JP4606985B2 - Wireless communication system - Google Patents

Description

  The present invention relates to a wireless communication system that can efficiently set an optimized route that does not pass through a home agent between a mobile terminal or a terminal accommodated in a mobile router and a communication partner terminal.

  In Mobile-IPv6, in order to switch the transfer route when a mobile terminal moves, the Mobile-IPv6 protocol must be running not only on the mobile terminal but also on the other terminal that communicates with the mobile terminal. There is. If the partner terminal does not support the Mobile-IPv6 protocol, the packet to be transmitted to the mobile terminal is transferred to the mobile terminal via the home agent HA linked to the home link to which the mobile terminal is normally connected. The Therefore, in such a case, there are problems such as an increase in transfer delay and concentration of traffic in the home agent HA.

  Therefore, in Patent Document 1, upon receiving a location registration update notification from the mobile terminal, a correspondence table between the current care-of address used by the mobile terminal at the destination and the address (home address) unique to the mobile terminal The proxy router on the communication path between the mobile terminal and the communication partner terminal stores it in place of the communication partner terminal, and the proxy router receives a packet addressed to the home address of the mobile terminal from the communication partner terminal. Referring to the stored correspondence table, the home address in the destination address area of the packet header is replaced with a care-of address, and a packet with the home address stored in the routing option header is transmitted by adding a routing option header. Thus, in Patent Document 1, a mobile terminal can communicate with a communication partner terminal that does not support mobile IP without going through a home agent.

JP 2002-185520 A (page 17, FIG. 9)

  According to the prior art described in Patent Document 1, since the mobile terminal does not transmit the location registration update notification to the proxy router unless it has actually moved, until the location registration update process is completed after the move, There is a problem that communication cannot be performed on the optimal route between the mobile terminal and the communication partner terminal.

  Further, according to the above-described conventional technology, when the communication partner terminal changes as the mobile terminal moves (for example, when content is downloaded from a local server in the vicinity of the destination wireless base station), the mobile terminal There was a problem that the address of the communication partner terminal at the destination could not be acquired and the location registration update notification could not be transmitted.

  Furthermore, according to the above prior art, in the case where the communication partner terminal of the mobile terminal changes as the mobile terminal moves, and the communication partner terminal does not support mobile IP, the mobile router acting as a proxy for the communication partner terminal The proxy router that stores the correspondence table between the current care-of address used at the destination and the address unique to the mobile terminal (home address) is also changed, but the mobile router cannot obtain the address of the proxy router at the destination There was a problem that the location registration update notification could not be transmitted.

  The present invention has been made in view of the above, and immediately after moving a mobile terminal or a mobile router, it passes through a home agent between the mobile terminal and the communication partner terminal or between the terminal under the mobile router and the communication partner terminal. An object of the present invention is to obtain a wireless communication system that can start communication on an optimum route without any problem.

  Further, the present invention provides a communication between a mobile terminal or a terminal under a mobile router and a communication partner terminal immediately after the movement of the mobile terminal or the mobile router when the communication partner terminal is changed as the mobile terminal or the mobile router moves. An object of the present invention is to obtain a wireless communication system capable of starting communication on an optimum route.

  Further, in the present invention, when the communication partner terminal does not support the mobile IP, immediately after the movement of the mobile terminal or the mobile router, the communication starts between the mobile terminal or the terminal under the mobile router and the communication partner terminal on the optimal route. An object of the present invention is to obtain a wireless communication system.

  In order to solve the above-described problems and achieve the object, the present invention provides a wireless communication system that performs communication between a mobile terminal and a communication partner terminal via an access router. A pre-location registration message including the care-of address used at the destination and the home address of the mobile terminal is transmitted to the communication partner terminal via the connected access router, and the pre-location registration message is transmitted after the movement. The communication partner terminal creates and transmits a packet to the communication partner terminal using the care-of address, and when the communication partner terminal receives the pre-position registration message, the care-of address after the movement of the mobile terminal based on the pre-position registration message and A home address correspondence is created and stored, and then the movement of the mobile terminal is detected. With updates the correspondence between the address and the home address, and transmits created packet to the mobile terminal by using the correspondence relationship that the update.

  According to the present invention, since the care-of address at the destination of the mobile terminal is notified to the communication partner terminal before the mobile terminal moves, immediately after the mobile terminal moves between the mobile terminal and the communication partner terminal. There is an effect that communication on the shortest and optimum route can be started without going through the home agent.

  Embodiments of a wireless communication system according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
FIG. 1 is a configuration diagram of a mobile IP network to which Embodiment 1 of the present invention is applied. In FIG. 1, the home agent HA is connected to access routers AR1 and AR2, and the access routers AR1 and AR2 accommodate radio base stations AP1 and AP2, respectively. The radio base station AP1 covers the radio area Area # 1, and the radio base station AP2 covers the radio area Area # 2. The MN is a mobile terminal, and the mobile terminal MN and the radio base stations AP1 and AP2 are connected by radio. In this case, the mobile terminal MN transmits / receives a packet to / from a communication counterpart terminal (hereinafter also referred to as a counterpart terminal) CN accommodated in the access router AR1 through a radio line.

  FIG. 2 is a diagram showing a header configuration of an IP packet transferred between the mobile terminal MN and the counterpart terminal CN in the first embodiment. FIG. 3 is a diagram showing a sequence of control messages among the mobile terminal MN, the access routers AR1 and AR2, and the counterpart terminal CN.

  Next, the operation will be described. In FIG. 1, it is assumed that the mobile terminal MN exists in the radio area Area # 1 under the control of the radio base station AP1, and then moves to the radio area Area # 2 under the control of the radio base station AP2. As indicated by an arrow (1) in FIG. 1, the mobile terminal MN communicates with the communication counterpart terminal CN via the radio base station AP1 and the access router AR1 without going through the home agent HA.

  The header structure of the IP packet corresponding to the arrow (1) in FIG. 1 is shown in FIGS. FIG. 2A shows the header configuration of an IP packet transmitted from the mobile terminal MN to the communication partner terminal CN. The destination address is “C”, which is the address of the communication partner terminal CN, and the transmission source address is “X” that is a care-of address under the access router AR1 of the mobile terminal MN is set, and “A” that is the home address of the mobile terminal MN is set in the home address option header. The counterpart terminal CN that has received the packet from the mobile terminal MN replaces the transmission source address with the value “A” of the home address option header, and recognizes the replaced address “A” as the actual packet transmission source. . The care-of address “X” is created using, for example, the network prefix assigned to the interface line of the access router AR1 and the MAC address of the mobile terminal MN.

  On the other hand, in the IP packet transmitted from the communication counterpart terminal CN to the mobile terminal MN, as shown in FIG. 2B, the destination address is “X”, which is the care-of address of the mobile terminal MN, and the source address is Sets “C”, which is the address of the partner terminal CN, and “A”, which is the home address of the mobile terminal MN, in the routing header. The mobile terminal MN that has received the packet from the communication counterpart terminal CN replaces the destination address with the value “A” of the routing header, and recognizes the replaced address “A” as the actual packet transmission destination.

  Next, a control information sequence will be described with reference to FIG. The access router AR1 transmits the network prefix (prefix of the wireless area Area # 1 in the area) assigned to the interface line of the access router AR1 to which the radio base station AP1 is connected to the router advertisement message periodically transmitted to the subordinate terminal. ), And the network prefix assigned to the interface line of the access router AR2 to which the radio base station AP2 is connected (prefix of the radio area Area # 2 where the mobile terminal MN moves next).

  The mobile terminal MN that has received the router advertisement message sets an optimized communication path between the mobile terminal MN and the communication partner terminal CN before moving to the radio area Area # 2 (subordinate to the radio base station AP2). Then, a prior location registration request message is transmitted to the communication partner terminal CN. This pre-location registration request message and its response message correspond to the arrow (2) in FIG. The pre-location registration request message includes the home address “A” of the mobile terminal MN and the care-of address “Y” in the radio area Area # 2 that moves next. The care-of address “Y” is created using, for example, the network prefix assigned to the interface line of the access router AR2 and the MAC address of the mobile terminal MN.

  The communication counterpart terminal CN has a location registration table that stores the correspondence between the care-of address and home address of each mobile terminal MN, and before receiving the pre-location registration request message from the mobile terminal MN, In the location registration table for the terminal MN, the care-of address is “X” (care-of address under the access router AR1) and the home address is “A”. Upon receiving the pre-location registration request message, the communication counterpart terminal CN includes a care-of address “Y” and a home address “A” included in the pre-location registration request message in the pre-location registration table managed separately from the location registration table. Are set and stored, and this setting information is used as position information at the next movement destination of the mobile terminal MN.

  The mobile terminal MN receives the router advertisement including the network prefix of the radio area Area # 2 from the access router AR2 or detects the establishment of the radio link with the radio base station AP2 under the condition of FIG. As shown by the arrow (3), communication with the communication partner terminal CN is started via the access router AR2. The header configuration of the IP packet at that time is shown in FIGS. FIG. 2C shows the header structure of a packet transmitted from the mobile terminal MN to the communication partner terminal CN. The destination address is “C”, which is the address of the communication partner terminal CN, and the transmission source address is “Y”, which is a care-of address under AR2 of the mobile terminal MN, is set, and “A”, which is the home address of the mobile terminal MN, is set in the home address option header. Receiving this packet, the correspondent terminal CN replaces the transmission source address with the value “A” of the home address option header, and recognizes the replaced address “A” as the actual packet transmission source.

  On the other hand, for the IP packet transmitted from the communication counterpart terminal CN to the mobile terminal MN, as shown in FIG. 2D, the destination address “Y”, which is the care-of address of the mobile terminal MN, and the source address Sets “C” as the address of the communication partner terminal CN, and sets “A” as the home address of the mobile terminal MN in the routing header. The mobile terminal MN that has received this packet replaces the destination address with the value “A” of the routing header, and recognizes the replaced address “A” as the actual packet transmission destination.

  When receiving the packet shown in FIG. 2C, the correspondent terminal CN receives the care-of address (in this case, “Y”) for the mobile terminal MN stored in the pre-location registration table and the header of the received packet. Based on the match with the source address set in the source address area (in this case, “Y”), it is determined that the packet has been transferred through a new route from the destination, and the contents of the care-of address in the location registration table are Replaced with the contents of the care-of address in the pre-location registration table (from care-of address X to Y). Thereafter, the header shown in FIG. 2D is set for the mobile terminal MN according to the new location registration table. Send the packet.

  In addition, after the movement is completed, the mobile terminal MN transmits a location registration message including the set of the current care-of address and the home address of the mobile terminal MN to the home agent HA, and notifies the home agent HA of the location change.

  As shown in FIG. 4, after the mobile terminal MN completes the movement, the mobile terminal MN transmits a movement completion notification message to the counterpart terminal CN, and the counterpart terminal CN determines the path switching by receiving the movement completion notification message. The content of the care-of address in the location registration table is replaced with the content of the care-of address in the pre-location registration table (from care-of address X to Y). Thereafter, the mobile terminal MN is in accordance with the new location registration table (D in FIG. ) May be set to transmit a packet. Note that the mobile terminal MN recognizes the detection of movement by inputting a radio section handover completion notification from the radio.

  As described above, in the first embodiment, the access router AR notifies the mobile terminal MN in advance of the network prefix necessary for generating a care-of address to be used at the next destination of the mobile terminal MN. The terminal MN transmits a pre-location registration request message including the care-of address used at the next destination based on the network prefix and the home address of the mobile terminal MN to the counterpart terminal CN, and the counterpart terminal CN transmits the pre-location registration request. Based on the message, the care-of address and home address at the destination of the mobile terminal are stored, and the counterpart terminal CN detects the packet reception on the new route after moving from the mobile terminal MN, or moves from the mobile terminal MN. It is determined that the communication route with the mobile terminal MN has been switched by receiving the completion notification, and transmitted to the mobile terminal MN. Since the care-of address set as the destination address of the packet to be transferred is switched to the care-of address after the movement, communication between the mobile terminal MN and the communication partner terminal CN immediately after the movement is performed through the shortest and optimum route without going through the home agent HA. Can continue.

Embodiment 2. FIG.
In the first embodiment, the mobile terminal MN that terminates the mobile IP protocol is assumed. However, in the second embodiment, the mobile router MR that accommodates a plurality of terminals that do not support the mobile IP protocol is placed at the position of the mobile terminal MN. The case of deployment will be shown. In the second embodiment, components that achieve the same functions as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 5 is a configuration diagram of a network to which the second embodiment is applied. In FIG. 5, it is assumed that the mobile router MR accommodates two sub-networks, and the terminal Node1 exists in the sub-network with the network prefix “F” and the terminal Node 2 exists in the sub-network with the network prefix “G”. The terminal Node1 moves from the wireless area Area # 1 under the access router AR1 to the wireless area Area # 2 under the access router AR2 including the mobile router MR while continuing to communicate with the counterpart terminal CN.

  FIG. 6 is a diagram illustrating a header configuration of an IP packet transferred between the mobile router MR and the counterpart terminal CN in the second embodiment. FIG. 7 is a diagram showing a control message sequence among the terminal Node1, the mobile router MR, the access routers AR1 and AR2, and the counterpart terminal CN.

  Next, the operation will be described. In FIG. 5, the terminal Node1 and the terminal Node2 exist under the mobile router MR, and the mobile router MR exists in the radio area Area # 1 that is the radio area of the radio base station AP1 and is subordinate to the access router AR1. It is assumed that the mobile station is in the service area and then moves to the wireless area Area # 2 which is the wireless area of the wireless base station AP2 and is under the control of the access router AR2.

  As indicated by an arrow (5) in FIG. 5, the terminal Node1 communicates with the counterpart terminal CN via the radio base station AP1 and the access router AR1 without going through the home agent HA. The header structure of the IP packet corresponding to the arrow (5) in FIG. 5 is shown in FIGS. FIG. 6A shows the header configuration of a packet transmitted from the terminal Node1 to the counterpart terminal CN. The header portion from the terminal Node1 to the mobile router MR is the address of the counterpart terminal CN as the destination address “ “C” is set as the source address “D”, which is the address of the terminal Node1. In the mobile router MR, “C”, which is the address of the partner terminal CN, is additionally set as an outer header, and “X”, which is a care-of address under the access router AR1 of the mobile router MR, is set as the destination address. . The counterpart terminal CN that has received this packet deletes the outer header and recognizes the source address “D” of the inner header as the packet source.

  On the other hand, as shown in FIG. 6B, for the packet from the communication partner terminal CN to the terminal Node1, the destination address of the inner header is “D”, which is the address of the terminal Node1, and the source address is communication. “C” that is the address of the partner terminal CN is set, “X” that is the care-of address of the mobile router MR is set as the destination address of the outer header, and “C” that is the address of the communication partner terminal CN is set as the source address. Set. The mobile router MR removes the outer header of the received packet and transmits it to the terminal Node1.

  Next, a control information sequence will be described with reference to FIG. The access router AR1 transmits a network prefix assigned to the interface line of the access router AR1 to which the radio base station AP1 is connected to the router advertisement message periodically transmitted to the subordinate terminal and the mobile router. 1) and a network prefix assigned to the interface line of the access router AR2 to which the radio base station AP2 is connected (a prefix of the radio area Area # 2 to which the mobile router MR moves next).

  The mobile router MR that has received the router advertisement message sets an optimized communication path between the subordinate terminal Node1 and the counterpart terminal CN before moving to the radio area Area # 2 (under AR2). A prior location registration request message is transmitted to the CN. This pre-location registration request message and its response message correspond to the arrow (6) in FIG. In the mobile router MR, the address “D” of the terminal Node1, the network prefix of the subnetwork to which the terminal Node1 belongs (in this case “F”), and the address “C” of the communication partner terminal CN are set in advance. In the pre-location registration request message, the router MR sends the home address “A” of the mobile router MR, the care-of address “Y” of the mobile router MR in the next moving radio area Area # 2, and the prefix “of the network to which the terminal Node1 belongs. "F" is transmitted.

  The content of the location registration table corresponding to the mobile router MR before receiving the advance location registration request message in the partner terminal CN is that the care-of address is “X” (care-of address under the access router AR1), and the home address of the mobile router MR Is “A” and the corresponding network prefix is “F”. When the counterpart terminal CN receives the pre-location registration request message, the care-of address “Y” ((care-of address under the access router AR2), MR home address “A”, and the corresponding network prefix “F” are stored in the pre-location registration table. Set and memorize.

  The mobile router MR receives the router advertisement including the network prefix in the radio area Area # 2 from the access router AR2 or detects the establishment of the radio link with the radio base station AP2 on the condition of the communication route. As shown by the arrow (7) in FIG. 5, the communication path is switched through the access router AR2. The header configuration of the IP packet at that time is shown in FIGS.

  FIG. 6C shows a header configuration of a packet from the terminal Node1 to the mobile router MR and the partner terminal CN. The packet from the terminal Node1 is the address of the communication partner terminal CN as a destination address. C ”, and the address“ D ”of the terminal Node1 is set as the source address. In the mobile router MR, an outer header is added to this packet. The destination address of the outer header is “C” that is the address of the communication partner terminal CN, and the source address is the subordinate of the access router AR2 of the mobile router MR. A care-of address “Y” is set. The counterpart terminal CN that has received this packet removes the outer header and recognizes the source address “D” of the inner header as the packet source.

  On the other hand, as shown in FIG. 6D, for the packet from the communication partner terminal CN toward the terminal Node1, the destination address of the outer header is “Y”, which is the care-of address of the mobile router MR, and the transmission source address. Is set to "C" which is the address of the communication partner terminal CN, the address "D" of the terminal Node1 is set to the destination address of the inner header, and "C" which is the address of the communication partner terminal CN is set to the transmission source address. The The mobile router MR removes the outer header of the received packet and transmits it to the terminal Node1.

  When receiving the packet shown in FIG. 6C, the communication partner terminal CN receives the care-of address (in this case, “Y”) for the mobile router MR stored in the pre-location registration table, and the received packet Based on the match with the source address (in this case, “Y”) set in the source address area of the header part, it is determined that the packet has been transferred through a new route from the destination, and the care-of address of the location registration table The contents are replaced with the contents of the care-of address in the pre-position registration table (from care-of address X to Y). Thereafter, for terminals having the address of network prefix “F” (including terminal Node1), the new position registration table Accordingly, each header shown in FIG. 6D is set and a packet is transmitted.

  Further, after the movement is completed, the mobile router MR transmits a location registration message including a set of the current care-of address and home address of the mobile router MR to the home agent HA, and notifies the home agent HA of the location change.

  As shown in FIG. 8, after the mobile router MR completes the movement, it transmits a movement completion notification message to the communication partner terminal CN, and the communication partner terminal CN detects the path switching by receiving the movement completion notification message. Then, the content of the care-of address in the location registration table is replaced with the content of the care-of address in the pre-location registration table (from care-of address X → Y). Thereafter, the mobile router MR is in accordance with the new location registration table in FIG. A packet may be transmitted by setting each header shown in (D). Note that the mobile router MR recognizes the detection of movement based on the input of the wireless section handover completion notification from the wireless device.

  In the header configuration of FIG. 6, the packet from the mobile router MR to the communication partner terminal CN and the packet from the communication partner terminal CN to the mobile router MR are both encapsulated and transmitted by the outer header. As shown, the option header can be used to reduce header overhead.

  9A shows a packet header in the direction of the terminal Node1 → the mobile router MR → the communication partner terminal CN when the mobile router MR is located in the radio area Area # 1, and FIG. Similarly, the configuration of the packet header in the direction of the communication counterpart terminal CN → mobile router MR → terminal Node 1 when the mobile router MR is located in the wireless area Area # 1 is shown. In (A) of FIG. 9, the header configuration of the transmission packet from the terminal Node1 and the setting contents thereof are the same as in (A) of FIG. 6, but in the IP header from the mobile router MR to the communication counterpart terminal CN. The home address option header is added, the care-of address “X” of the mobile router is added to the source address, and “D” (address of the terminal Node 1) that is the source address of the transmission packet from the terminal Node 1 is added to the home address option header Set.

  The communication partner terminal CN sets the content of the home address option header of the received packet as the transmission source address, and recognizes the value (in this case, the address “D” of the terminal Node 1) as the transmission source address. In FIG. 9B, from the communication counterpart terminal CN to the mobile router MR, a routing header is added to the IP header, the care-of address “X” of the mobile router is set as the destination address, and the terminal Node 1 An address “D” (the address of the terminal Node1) is set. The mobile router MR sets the content of the routing header of the received packet as the transmission source address (in this case, the address “D” of the terminal Node1), and transmits it to the terminal Node1.

  (C) in FIG. 9 shows a packet header in the direction of the terminal Node1 → the mobile router MR → the communication counterpart terminal CN when the mobile router MR is located in the radio area Area # 2, and in the home address option header, “D” (the address of the terminal Node1), which is the transmission source address of the transmission packet from the terminal Node1, is set. FIG. 9D shows the structure of the packet header in the direction of the communication counterpart terminal CN → mobile router MR → terminal Node 1 when the mobile router MR is located in the wireless area Area # 2. “D” (the address of the terminal Node1), which is the address of the terminal Node1, is set.

  As described above, in the second embodiment, the access router AR notifies the mobile router MR in advance of the network prefix necessary for generating the care-of address at the next destination of the mobile router MR. The MR generates a care-of address at the destination based on the network prefix, and sets an optimized communication path between the terminal Node1 and the communication partner terminal CN for the communication partner terminal CN that is the communication destination of the subordinate terminal Node1. In order to set, a pre-location registration request message including a care-of address at the next destination of the mobile router MR, a home address of the mobile router MR, and a network prefix of a subnet to which the terminal Node1 belongs is transmitted to the communication counterpart terminal CN. , The care-of address and home address at the destination of the mobile router MR And the network prefix to be route optimized, and the communication partner terminal CN detects packet reception on the new route after moving from the mobile router MR, or receives movement completion notification from the mobile router MR. Thus, it is determined that the communication route has been switched along with the movement of the mobile router MR, and the care-of address set as the destination address is set to the care-of address after movement for the packet transmitted to the address having the network prefix to be route-optimized. Since switching is performed, communication between the terminal Node1 accommodated in the mobile router MR and the communication counterpart terminal CN can be continued on the shortest and optimum route without going through the home agent HA immediately after movement. .

  In addition, as described above, the mobile router communicates not only with the communication counterpart terminal CN of the terminal Node1 under the mobile router MR, but also with a communication counterpart terminal designated in advance and a communication counterpart terminal of a specific service class / application IP flow. The above route optimization process may also be performed in such communication.

Embodiment 3 FIG.
In the first embodiment, the case where the communication counterpart terminal CN of the mobile terminal MN supports the mobile IP protocol has been described. However, in the third embodiment, the communication counterpart terminal CN in the first embodiment supports the mobile IP protocol. If the mobile terminal MN has not moved, the communication is started between the mobile terminal MN and the communication counterpart terminal CN via the optimized route immediately after the mobile terminal MN moves. In the third embodiment, components that achieve the same functions as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 10 shows a network configuration to which the third embodiment is applied. In the third embodiment, a proxy router (CN-side proxy Router, C-side proxy Router) 10 is provided in front of the communication counterpart terminal CN in the network configuration shown in FIG. The mobile IP protocol is terminated instead of the CN, and a communication route optimization procedure is executed with the mobile terminal MN. The counterpart terminal CN shown in FIG. 10 does not support the mobile IP protocol.

  FIG. 11 is a diagram illustrating a control sequence among the mobile terminal MN, the access routers AR1 and AR2, the proxy router 10, and the communication counterpart terminal CN. Next, the operation will be described.

  In FIG. 10, the mobile terminal MN exists under the control of the radio base station AP1, and communicates with the counterpart terminal CN, the radio base station AP1, the access router AR1, and the proxy router 10 without going through the home agent HA. ing. The header configuration of the IP packet between the mobile terminal MN and the proxy router 10 when the mobile terminal MN is located under the radio base station AP1 (radio area Area # 1 = subordinate to the access router AR1) is described in the first embodiment. This is the same as (A) and (B) in FIG. Also, the header configuration of the IP packet between the mobile terminal MN and the proxy router 10 when the mobile terminal MN moves under the control of the radio base station AP2 (Area # 2 = subordinate of the access router AR2) is the same as in the first embodiment. This is the same as (C) and (D) of FIG.

  On the other hand, for the packet between the communication partner terminal CN and the proxy router 10 indicated by the arrow (8) in FIG. 10, the communication partner terminal CN sets the destination address to the home address “A” of the mobile terminal MN and the source address. , The proxy router 10 sets the destination address as the address “C” of the communication partner terminal CN and the source address of the mobile terminal MN as the source address “A”. ”Is sent. This is to make the communication partner terminal CN perform communication without being aware of the mobile IP.

  Next, the control sequence will be described with reference to FIG. The access router AR1 periodically transmits the network prefix (prefix of the existing wireless area Area # 1 in the area) to the router advertisement message transmitted to the terminal under its control in the interface line of the access router AR1 to which the radio base station AP1 is connected. ), And the network prefix assigned to the interface line of the access router AR2 to which the radio base station AP2 is connected (prefix of the radio area Area # 2 where the mobile terminal MN moves next).

  The mobile terminal MN that has received the router advertisement message sets an optimized communication path between the mobile terminal MN and the communication partner terminal CN before moving to the wireless area Area # 2 (subordinate to the access router AR2). A prior location registration request message is transmitted to the proxy router 10 that accommodates the communication partner terminal CN. It is assumed that the mobile terminal MN obtains in advance the address of the proxy router 10 corresponding to the communication partner terminal CN. This pre-location registration request and its response message correspond to the arrow (2) in FIG. The pre-location registration request message includes the home address “A” of the mobile terminal MN and the care-of address “Y” in the radio area Area # 2 that moves next.

  The proxy router 10 has a location registration table that stores the correspondence between the care-of address and home address of each mobile terminal MN. Before receiving the pre-location registration request message from the mobile terminal MN, the proxy router 10 In the location registration table for the MN, the care-of address is “X” (care-of address under the access router AR1), and the home address is “A”. When the proxy router 10 receives the advance location registration request message, the proxy router 10 includes the care-of address “Y” and the home address “A” included in the advance location registration request message in the advance location registration table managed separately from the location registration table. The group is set and stored, and this setting information is used as position information at the next destination of the mobile terminal MN.

  When the proxy router 10 receives the packet shown in (C) of FIG. 2 from the mobile terminal MN as in the case of the communication counterpart terminal CN of the first embodiment, the proxy router 10 stores information on the mobile terminal MN stored in the pre-location registration table. Based on the match between the care-of address (in this case “Y”) and the source address set in the source address area of the header portion of the received packet (in this case “Y”), the packet is new from the destination. The content of the care-of address in the location registration table is replaced with the content of the care-of address in the pre-location registration table (from care-of address X to Y). Thereafter, a new location registration is performed for the mobile terminal MN. According to the table, the header shown in FIG. 2D is set and the packet is transmitted.

  In addition, after the movement is completed, the mobile terminal MN transmits a location registration message including the set of the current care-of address and the home address of the mobile terminal MN to the home agent HA, and notifies the home agent HA of the location change.

  As shown in FIG. 12, after the mobile terminal MN completes the movement, the mobile terminal MN transmits a movement completion notification message to the proxy router 10, and the proxy router 10 determines the path switching by receiving the movement completion notification message, The content of the care-of address in the location registration table is replaced with the content of the care-of address in the pre-location registration table (from care-of address X to Y). Thereafter, the mobile terminal MN is in accordance with the new location registration table (D in FIG. ) May be set to transmit a packet.

  As described above, in the third embodiment, the access router AR notifies the mobile terminal MN in advance of the network prefix necessary for generating the care-of address at the next destination of the mobile terminal MN, and moves The terminal MN generates a care-of address based on the network prefix, and sets an optimized communication path between the mobile terminal MN and the communication partner terminal CN to the proxy router 10 that terminates the mobile IP protocol instead of the communication partner terminal CN. In order to set, a pre-location registration request message including a care-of address and home address at the destination of the mobile terminal MN is transmitted, the care-of address and home address at the destination are stored in the proxy router 10, and the proxy router 10 is a packet reception detection on a new route after moving from the mobile terminal MN, or mobile terminal MN When the movement completion notification is received, it is determined that the communication path has been switched with the movement of the mobile terminal MN, and the care-of address after the movement is stored that stores the care-of address set as the destination address of the packet transmitted to the mobile terminal MN. Therefore, communication between the mobile terminal MN and the communication counterpart terminal CN that does not support the mobile IP protocol can be continued in the shortest and optimum route without going through the home agent HA immediately after the movement.

Embodiment 4 FIG.
In the second embodiment, the case where the communication partner terminal CN of the mobile terminal MN supports the mobile IP protocol has been described. However, in the fourth embodiment, the communication partner terminal CN in the second embodiment supports the mobile IP protocol. If the mobile terminal MN has not moved, the communication is started between the mobile terminal MN and the communication counterpart terminal CN via the optimized route immediately after the mobile terminal MN moves. In the fourth embodiment, components that achieve the same functions as those in the second embodiment are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 13 is a diagram showing a network configuration to which the fourth embodiment is applied. In the fourth embodiment, a proxy router (CN-side proxy Router) is placed in front of the communication counterpart terminal CN in the network configuration shown in FIG. , C-side proxy Router) 10 is deployed, the proxy router 10 terminates the mobile IP protocol instead of the communication partner terminal CN, and executes a communication route optimization procedure with the mobile terminal MN. The communication counterpart terminal CN shown in FIG. 10 does not support the mobile IP protocol.

  FIG. 14 is a diagram illustrating a control sequence among the terminal Node1, the mobile router MR, the access routers AR1 and AR2, and the proxy router 10 in the fourth embodiment. Next, the operation will be described. In FIG. 13, the terminal Node1 and the terminal Node2 exist under the mobile router MR, and the mobile router MR exists within the wireless area Area # 1 (the wireless area of the wireless base station AP1 and the access router AR1). The terminal Node1 communicates with the communication partner terminal CN accommodated in the proxy router 10 via the radio base station AP1 and the access router AR1 without going through the home agent HA.

  The header configuration of the IP packet between the terminal Node1, the mobile router MR, and the proxy router 10 when the terminal Node1 is located under the radio base station AP1 (radio area Area # 1 = subordinate to the access router AR1) This is the same as (A) and (B) of FIG. 6 and (A) and (B) of FIG. The header configuration of the IP packet between the terminal Node1, the terminal Node1, the mobile router MR, and the proxy router 10 when the mobile terminal MN moves under the control of the radio base station AP2 (Area # 2 = under the access router AR2) is as follows: Similarly, it is the same as (C) and (D) of FIG. 6 or (C) and (D) of FIG. 9 used in the second embodiment.

  On the other hand, for the packet between the communication partner terminal CN and the proxy router 10 indicated by the arrow (8) in FIG. 13, the communication partner terminal CN communicates the destination address to the address “D” of the terminal Node1 and the transmission source address. A packet in which the address “C” of the partner terminal CN is set, while the proxy router 10 sets the destination address as the address “C” of the partner terminal CN and the address “D” of the terminal Node1 as the source address Send the packet. This is to make the communication partner terminal CN perform communication without being aware of the mobile IP.

  Next, the control sequence will be described with reference to FIG. The access router AR1 periodically transmits a network prefix assigned to the interface line of the access router AR1 to which the wireless base station AP1 is connected to the router advertisement message transmitted to the terminal and mobile router under its control (the wireless area Area # in the area). 1) and a network prefix assigned to the interface line of the access router AR2 to which the radio base station AP2 is connected (a prefix of the radio area Area # 2 to which the mobile router MR moves next).

  The mobile router MR that has received the router advertisement message sets an optimized communication path between the subordinate terminal Node1 and the communication counterpart terminal CN before moving to the wireless area Area # 2 (under the access router AR2). The prior location registration request message is transmitted to the proxy router 10 in which the communication partner terminal CN is accommodated. This pre-location registration request and its response message correspond to the arrow (6) in FIG. It is assumed that the address “D” of the terminal Node1, its network prefix “F”, and the address of the proxy router 10 corresponding to the communication partner terminal CN that is the communication partner are set in advance in the mobile router MR. The pre-location registration request message transmitted from the mobile router MR to the proxy router 10 includes the home address “A” of the mobile router MR, the care-of address “Y” of the mobile router MR in the radio area Area # 2 that moves next, And the prefix “F” of the network to which the terminal Node1 belongs.

  The proxy router 10 has a location registration table that stores the correspondence between the care-of address of the mobile router MR and the home address. Before receiving the pre-location registration request message from the mobile router MR, the proxy router MR In the location registration table, the care-of address is “X” (care-of address under the access router AR1), the home address is “A”, and the corresponding network prefix is “F”. When the proxy router 10 receives the advance location registration request message, the proxy router 10 includes a care-of address “Y” ((under the access router AR2) in the advance location registration table managed separately from the location registration table. ), Home address “A”, and corresponding network prefix “F” are set and stored, and this setting information is used as position information at the next destination of the mobile router MR.

  The mobile router MR receives the router advertisement including the network prefix in the radio area Area # 2 from the access router AR2 or detects the establishment of the radio link with the radio base station AP2 under the condition of FIG. As shown by the arrow (7), transfer of a packet between the terminal Node1 and the communication partner terminal CN is started on a new route via the access router AR2.

  When the proxy router 10 receives the packet shown in (C) of FIG. 6 or (C) of FIG. 9 similarly to the communication counterpart terminal CN of the second embodiment, the proxy router 10 stores the mobile stored in the pre-position registration table. The packet moves based on a match between the care-of address for the router MR (in this case, “Y”) and the source address (in this case, “Y”) set in the source address area of the header of the received packet. The content of the care-of address in the location registration table is replaced with the content of the care-of address in the pre-location registration table (from care-of address X to Y). Transmits a packet by setting the header shown in FIG. 6D or 9D according to the new location registration table.

  The mobile router MR transmits a location registration message including the current care-of address and home address of the mobile router MR and the network prefix of the accommodated subnet to the home agent HA after the movement is completed. Notify position change.

  As shown in FIG. 15, after the mobile router MR completes the movement, the mobile router MR transmits a movement completion notification message to the proxy router 10, and the proxy router 10 determines the path switching by receiving the movement completion notification message, The content of the care-of address in the location registration table is replaced with the content of the care-of address in the pre-location registration table (from care-of address X → Y). Alternatively, each header shown in FIG. 9D may be set to transmit a packet.

  As described above, in the fourth embodiment, the access router AR notifies the mobile router MR in advance of the network prefix necessary for generating the care-of address at the next destination of the mobile router MR. The MR generates a care-of address at the destination based on the network prefix, and communicates with the terminal Node1 to the proxy router 10 that terminates the mobile IP protocol on behalf of the communication partner terminal CN that is the communication destination of the subordinate terminal Node1. Pre-location registration including a care-of address at the next destination of the mobile router MR, a home address of the mobile router MR, and a network prefix of the subnet to which the terminal Node1 belongs in order to set an optimized communication path between the counterpart terminals CN The request message is transmitted, and the proxy router 10 The router 10 stores the care-of address and home address at the destination of the router, and the network prefix to be route-optimized. Further, the proxy router 10 detects packet reception on the new route after moving from the mobile router MR, or mobile Receiving the movement completion notification from the router MR, it is determined that the communication path has been switched along with the movement of the mobile router MR, and the packet to be sent to the address having the network prefix to be route optimized is set as the destination address. Since the address is switched to the care-of address after the movement, the terminal Node1 accommodated in the mobile router and the communication partner terminal CN that does not support the mobile IP protocol can be switched to the shortest without going through the home agent HA immediately after the movement. And optimal Communication can be continued along the route.

Embodiment 5 FIG.
In the fifth embodiment, when the communication partner terminal CN of the mobile terminal MN is changed by the movement of the mobile terminal MN, the optimization is performed between the mobile terminal MN and the changed communication partner terminal CN immediately after the mobile terminal MN moves. Route communication can be started.

  FIG. 16 is a diagram illustrating a network configuration according to the fifth embodiment. In FIG. 16, the communication partner terminal CN of the mobile terminal MN is CN1 in the wireless area Area # 1, and is CN2 in the wireless area Area # 2 after the movement. The IP address of the old communication partner terminal CN1 is “C”, and the new communication partner The IP address of the terminal CN2 is “E”.

  FIG. 17 is a diagram showing a control sequence in the fifth embodiment. Next, the operation will be described. In FIG. 16, the mobile terminal MN exists under the radio base station AP1, and communicates with the old communication counterpart terminal CN1, the radio base station AP1, and the access router AR1 without going through the home agent HA ( The route of arrow (1) in FIG. The header configuration of the IP packet between the mobile terminal MN and the old communication counterpart terminal CN1 when the mobile terminal MN is located under the radio base station AP1 (radio area Area # 1 = subordinate to the access router AR1) This is the same as (A) and (B) of FIG.

  Next, a control information sequence will be described with reference to FIG. The access router AR1 periodically transmits the network prefix (prefix of the existing wireless area Area # 1 in the area) to the router advertisement message transmitted to the terminal under its control in the interface line of the access router AR1 to which the radio base station AP1 is connected. ), And the network prefix assigned to the interface line of the access router AR2 to which the radio base station AP2 is connected (prefix of the radio area Area # 2 where the mobile terminal MN moves next), and further in the new radio area Area # 2 It transmits including the address “E” of the new communication partner terminal CN2.

  The mobile terminal MN that has received the router advertisement message sets an optimized communication path between the mobile terminal MN and the communication partner terminal CN before moving to the wireless area Area # 2 (subordinate to the access router AR2). A prior location registration request message is transmitted to the new communication partner terminal CN2. When transmitting this pre-location registration request message, the address “E” included in the router advertisement message is used as the address of the communication partner terminal CN2. The pre-location registration request and its response message correspond to the arrow (2) in FIG. The pre-location registration request message includes the home address “A” of the mobile terminal MN and the care-of address “Y” in the radio area Area # 2 that moves next.

  The new communication partner terminal CN2 stores the correspondence between the care-of address currently used by the mobile terminal MN and the home address, and the correspondence between the care-of address used after the mobile terminal MN moves and the home address. When receiving the pre-location registration request message, the communication counterpart terminal CN2 includes the care-of address “Y” and the home address included in the pre-location registration request message in the pre-location registration table. A set of “A” is set and stored.

  The mobile terminal MN receives the router advertisement including the network prefix of the radio area Area # 2 from the access router AR2 or detects the establishment of the radio link with the radio base station AP2 under the condition of FIG. As indicated by the arrow (3), communication with the new communication counterpart terminal CN2 is started via the access router AR2. The header configuration of the IP packet at that time is the same as (C) and (D) of FIG. 2 used in the first embodiment, but the address “C” becomes the address “E”.

  When the new communication partner terminal CN2 receives the packet of FIG. 2C from the mobile terminal MN, the new communication partner terminal CN2 has received the care-of address (in this case, “Y”) for the mobile terminal MN stored in the pre-location registration table. Based on the match with the source address (in this case, “Y”) set in the source address area of the header of the packet, it is determined that the mobile terminal MN has moved to the radio area Area # 2, The contents are transferred to the location registration table. Thereafter, the mobile terminal MN transmits the address “E” as the source address in the header configuration of FIG. 2D according to the contents of the location registration table. To do.

  After the movement is completed, the mobile terminal MN transmits a location registration message including the current care-of address of the mobile terminal MN and the home address to the home agent HA, and notifies the home agent HA of the location change.

  As described with reference to FIG. 4 in the first embodiment, the mobile terminal MN moves to the new communication partner immediately after moving to the radio area Area # 2 (subordinate to the radio base station AP2 = subordinate to the access router AR2). A movement completion notification may be transmitted to the terminal CN2, and the communication partner terminal CN2 may determine that the mobile terminal MN has moved to the wireless area Area # 2 upon receipt of the movement completion notification.

  In the above, the address of the new communication partner terminal CN2 at the destination of the mobile terminal MN is included in the router advertisement. However, the access router sends a new message to the mobile terminal MN as a new communication partner at the destination. The address of the terminal CN2 may be notified. Further, the home agent HA may receive the location registration message from the mobile terminal MN, and notify the mobile terminal MN of the address of the new communication counterpart terminal CN2 at the destination by a dedicated message. The address of the new communication counterpart terminal CN2 may be included in the location registration response message. Alternatively, when the home agent HA receives a location registration message from the mobile terminal MN, it instructs the communication counterpart terminal CN2 at the next destination to notify the mobile terminal MN of the address, and the next destination The address of the communication partner terminal CN2 may be notified to the mobile terminal MN by a dedicated message from the communication partner terminal CN2 in FIG.

  Further, not only the address of the communication partner terminal CN at the destination, but also the instruction information indicating whether or not the communication partner terminal CN valid in the current area is used at the next destination, or the communication partner terminal availability state You may make it notify to the mobile terminal MN together with (failure, temporarily unavailable).

  As described above, in the fifth embodiment, the access router AR uses the network prefix and destination necessary for generating a care-of address for the next destination of the mobile terminal MN in advance for the mobile terminal MN. The mobile terminal MN notifies the address of the communication counterpart terminal CN2 of the mobile terminal MN, the mobile terminal MN generates a care-of address based on the network prefix, and the mobile terminal MN responds to the address of the communication counterpart terminal CN2 at the notified destination. A pre-location registration request message including the home address with the care-of address at the destination of the MN is transmitted, and the care-of address of the mobile terminal MN at the destination and the home address of the mobile terminal MN are stored in the communication partner terminal CN2. In addition, the communication partner terminal CN2 at the moving destination receives a packet from the mobile terminal MN on the new route after moving. The mobile terminal MN determines that the mobile terminal MN has moved to the wireless area by receiving or receiving a movement completion notification from the mobile terminal MN, and sets the care-of address that has been notified in advance to the destination address of the packet transmitted to the mobile terminal MN Therefore, even if the communication partner terminal CN is changed as viewed from the mobile terminal MN immediately after the movement between the mobile terminal MN and the communication counterpart terminal CN2 at the destination, the shortest route is not required via the home agent HA. Communication can be started.

Embodiment 6 FIG.
In the sixth embodiment, when the communication counterpart terminal CN of the mobile terminal MN does not support mobile IP, when the communication counterpart terminal CN of the mobile terminal MN changes due to movement of the mobile terminal MN, the mobile terminal MN Immediately after moving, communication can be started between the mobile terminal MN and the communication partner terminal CN after the change through the optimized route.

  FIG. 18 is a diagram illustrating a network configuration according to the sixth embodiment. In FIG. 18, the communication partner terminal CN of the mobile terminal MN is CN1 in the wireless area Area # 1 and CN2 in the wireless area Area # 2 after movement, and the IP address of the old communication partner terminal CN1 is “C”. The IP address of the terminal CN2 is “E”. The communication partner terminals CN1 and CN2 do not support mobile IP, and a proxy router 10 that terminates the mobile IP protocol on behalf of the communication partner terminal CN1 is provided in front of the communication partner terminal CN1, and the communication partner terminal CN2 Is provided with a proxy router 11 that terminates the mobile IP protocol on behalf of the communication partner terminal CN2.

  FIG. 19 is a diagram showing a control sequence in the sixth embodiment. Next, the operation will be described. In FIG. 18, the mobile terminal MN is under the control of the radio base station AP1, and communicates with the counterpart terminal CN1, the radio base station AP1, and the access router AR1 without going through the home agent HA (FIG. 18). 18 arrow (1) path). The header configuration of the IP packet between the mobile terminal MN and the communication counterpart terminal CN when the mobile terminal MN is located under the radio base station AP1 (radio area Area # 1 = subordinate to the access router AR1) 2 is the same as (A) and (B) of FIG.

  Next, the control sequence will be described with reference to FIG. The access router AR1 periodically transmits the network prefix (prefix of the existing wireless area Area # 1 in the area) to the router advertisement message transmitted to the terminal under its control in the interface line of the access router AR1 to which the radio base station AP1 is connected. ), The network prefix assigned to the interface line of the access router AR2 to which the radio base station AP2 is connected (prefix of the radio area Area # 2 to which the mobile terminal MN moves next), and the communication partner in the radio area Area # 2 It transmits including the address “E” of the terminal CN2 and the IP address “J” of the proxy router 11 corresponding to the communication partner terminal CN2.

  The mobile terminal MN that has received this router advertisement message requests the pre-location registration request to the proxy router 11 corresponding to the communication counterpart terminal CN2 after moving before moving to the wireless area Area # 2 (subordinate to the access router AR2). Send a message. This pre-location registration request and its response message correspond to the arrow (2) in FIG. That is, the mobile terminal MN creates and transmits a pre-location registration request message to be transmitted to the proxy router 11 using the IP address “J” of the proxy router 11 included in the router advertisement message. The pre-location registration request message includes the home address “A” of the mobile terminal MN and the care-of address “Y” of the mobile terminal MN in the radio area Area # 2 that moves next.

  In the proxy router 11, a location registration table that stores the correspondence between the care-of address currently used by the mobile terminal MN and the home address, and a pre-store that stores the correspondence between the care-of address and the home address used after the mobile terminal MN moves. When the proxy router 11 receives the pre-location registration request message, the proxy router 11 includes a care-of address “Y” and a home address “A” included in the pre-location registration request message in the pre-location registration table. Set and store.

  The mobile terminal MN receives the router advertisement including the network prefix of the radio area Area # 2 from the access router AR2, or detects the establishment of the radio link with the radio base station AP2 under the condition of the access router AR2 Then, communication with the communication partner terminal CN2 is started via the proxy router 11. At this time, the mobile terminal MN starts communication using the address of the communication partner terminal CN2 as the address of the new communication partner terminal CN. The header configuration of the IP packet at that time is the same as (C) and (D) of FIG. 2 used in the first embodiment, but the address “C” becomes the address “E”.

  When the proxy router 11 receives the packet of FIG. 2C from the mobile terminal MN, the proxy router 11 cares about the mobile terminal MN (in this case, “Y”) stored in the pre-location registration table, and the received packet Based on the match with the source address (in this case, “Y”) set in the source address area of the header part, it is determined that the mobile terminal MN has moved to the radio area Area # 2, and the contents of the pre-location registration table are Then, the mobile terminal MN transmits the mobile terminal MN with the address “E” set as the source address in the header configuration of FIG. 2D according to the contents of the location registration table.

  After the movement is completed, the mobile terminal MN transmits a location registration message including the current care-of address of the mobile terminal MN and the home address to the home agent HA, and notifies the home agent HA of the location change.

  The mobile terminal MN, as shown in FIG. 12, immediately moves to the wireless area Area # 2 (subordinate to the radio base station AP2 = subordinate to the access router AR2), and then sends a movement completion notification message to the proxy router 11. The proxy router 11 determines that the mobile terminal MN has moved to the wireless area Area # 2 by receiving the movement completion notification message, and moves the contents of the pre-location registration table to the location registration table. A packet may be transmitted to the MN according to the contents of the location registration table.

  In the above, the address of the communication partner terminal CN2 at the destination of the mobile terminal MN and the address of the proxy router 11 corresponding to this communication partner terminal CN2 are included in the router advertisement. Alternatively, the address of the proxy router 11 may be notified to the mobile terminal MN by another message. . Further, the home agent HA may receive the location registration message from the mobile terminal MN, and notify the mobile terminal MN of these address information by a dedicated message. Furthermore, the address information is sent to the location registration response message. May be included. Further, in addition to the address information, information indicating the presence / absence of a proxy router may be included.

  As described above, in the sixth embodiment, the access router AR uses the network prefix and the destination necessary for generating the care-of address for the next destination of the mobile terminal MN in advance for the mobile terminal MN. The mobile terminal MN notifies the address of the communication partner terminal CN2 of the mobile terminal MN and the address of the proxy router 11 corresponding to the communication partner terminal CN2, and the mobile terminal MN generates a care-of address based on the network prefix, and the notified proxy router 11 To the address of the mobile terminal MN, a pre-location registration request message including the home address with the care-of address at the destination of the mobile terminal MN is transmitted, and the proxy router 11 stores the care-of address and home address at the destination of the mobile terminal MN. In addition, the proxy router 11 receives the packet from the mobile terminal MN on the new route after moving. Upon detection or reception of movement completion notification from the mobile terminal MN, it is determined that the mobile terminal MN has moved to the wireless area, and the care-of address that has been notified in advance is set as the destination address of the packet transmitted to the mobile terminal MN. Furthermore, since the mobile terminal MN communicates with the communication partner terminal CN using the address of the new communication partner terminal CN after the movement, immediately after the movement between the mobile terminal MN and the communication partner terminal CN2 that does not support mobile IP, Even if the communication partner terminal CN is changed as viewed from the mobile terminal MN, communication can be started on the shortest and optimum route without going through the home agent HA.

Embodiment 7 FIG.
In the seventh embodiment, a case will be described in which a terminal accommodated in the mobile router MR performs route optimization between a terminal and a communication partner terminal CN when communicating with a communication partner terminal CN that is different at a destination.

  FIG. 20 is a diagram illustrating a network configuration according to the seventh embodiment. In FIG. 20, the communication partner terminal CN of the terminal Node1 is CN1 in the wireless area Area # 1, and CN2 in the wireless area Area # 2 after movement. The IP address of the old communication partner terminal CN1 is “C”, and the new communication partner terminal The IP address of CN2 is “E”.

  FIG. 21 is a diagram showing a control sequence in the seventh embodiment. Next, the operation will be described. In FIG. 20, the mobile router MR that accommodates the terminal Node1 exists under the radio base station AP1, and the terminal Node1 passes through the communication counterpart terminal CN1 corresponding to the radio area Area # 1, the radio base station AP1, and the access router AR1. , Communication is performed without going through the home agent HA (route indicated by arrow (5) in FIG. 20). The header configuration of the IP packet between the terminal Node1 and the communication counterpart terminal CN1 when the mobile router MR is located under the radio base station AP1 (radio area Area # 1 = subordinate to the access router AR1) is the same as that of the second embodiment. 6 is the same as (A), (B) of FIG. 6 or (A), (B) of FIG.

  Next, a control sequence will be described with reference to FIG. The access router AR1 periodically transmits a network prefix assigned to the interface line of the access router AR1 to which the radio base station AP1 is connected to the router advertisement message transmitted to the terminal and the mobile router MR. # 1 prefix), the network prefix assigned to the interface line of the access router AR2 to which the radio base station AP2 is connected (prefix of the radio area Area # 2 to which the mobile router MR moves next), and further the radio area Area # 2 including the address “E” of the communication partner terminal CN2 in 2 and the identification information (ID) of the communication partner terminal CN that is a unique value in a plurality of areas.

  The mobile router MR that has received this router advertisement message makes a prior location registration request to the communication partner terminal CN2 that is the communication partner after the movement of the terminal Node1 before moving to the wireless area Area # 2 (under AR2). Send a message. This pre-location registration request and its response message correspond to the arrow (9) in FIG. In the mobile router MR, the correspondence relationship between the address “D” of the terminal Node1, the network prefix “F” to which the terminal Node1 belongs, and the ID of the communication partner terminal CN that is the communication partner of the terminal Node1 is set in advance. To do. The mobile router MR searches the network prefix of the corresponding terminal Node1 from the ID included in the router advertisement, and sends a pre-location registration request message to the IP address “E” of the communication partner terminal CN2 included in the router advertisement message. Send. In the pre-location registration request message, the home address “A” of the mobile router MR, the care-of address “Y” of the mobile router MR in the radio area Area # 2 to move next, and the network prefix “F” of the subnet to which the terminal Node1 belongs are included. Include.

  The communication partner terminal CN2 has a location registration table that stores the correspondence between the care-of address and home address currently used by the mobile router MR and the network prefix corresponding to the terminal Node1, and the care-of address and home address used after the mobile terminal MN moves. And a pre-location registration table that stores the correspondence relationship between the optimization target network prefixes, and when the communication partner terminal CN2 receives the pre-location registration request message, the pre-location registration request message is stored in the pre-location registration table. The set of the care-of address “Y”, the home address “A”, and the network prefix “F” to be optimized is set and stored.

  Further, the mobile router MR notifies the address “E” of the communication partner terminal CN2 included in the router advertisement message to the terminal Node1 corresponding to the ID.

  The mobile router MR accesses the communication path by either receiving a router advertisement including the network prefix of the radio area Area # 2 from the access router AR2 or detecting establishment of a radio link with the radio base station AP2. Switch to the communication path via the router AR2. At that time, the mobile router MR transmits a movement notification message to the terminal Node1. The terminal Node1 starts communication with the communication partner terminal CN2 when receiving the movement notification message from the mobile router MR. The header configuration of the IP packet transferred between the terminal Node1 and the communication counterpart terminal CN2 is the same as (C), (D) of FIG. 6 described in Embodiment 2 or (C), (D) of FIG. However, the address “C” is the address “E” of the communication partner terminal CN2.

  When the communication partner terminal CN2 receives the packet shown in FIG. 6C or FIG. 9C from the mobile router MR, it determines that the mobile terminal MN has moved to the wireless area Area # 2 in the same manner as described above. Then, the content of the pre-location registration table is moved to the location registration table. Thereafter, according to the content of the location registration table, for the packet including the network prefix “F” of the subnet to which the terminal Node1 belongs, D) or the header configuration shown in FIG. 9D, the address “E” is set as the transmission source address and transmitted.

  After the movement is completed, the mobile router MR transmits a location registration message including the set of the current care-of address and home address of the mobile router MR to the home agent HA, and notifies the home agent HA of the location change.

  As described with reference to FIG. 8 of the second embodiment, the mobile router MR immediately moves to the wireless area Area # 2 (subordinate to the radio base station AP2 = subordinate to the access router AR2). A movement completion notification may be transmitted to CN2, and communication counterpart terminal CN2 may determine that mobile router MR and terminal Node1 accommodated therein have moved to radio area Area # 2 upon receipt thereof.

  In the above description, the address and ID of the communication partner terminal CN2 at the destination of the node Node1 are included in the router advertisement. However, the address information (address and ID of the communication partner terminal CN2) is sent to the mobile router MR. You may make it notify with another message. The home agent HA receives the location registration message from the mobile router MR, notifies the address information to the mobile router MR by a dedicated message or a location registration response message, and the mobile router MR sends the above information to the terminal Node1. You may make it notify address information.

  As described above, in the seventh embodiment, the access router AR uses the network prefix and destination necessary for generating the care-of address at the next destination of the mobile router MR in advance for the mobile router MR. Of the communication partner terminal CN2 of the terminal Node1 and the ID of the communication partner terminal CN group that is a unique value in a plurality of areas, the mobile router MR generates a care-of address based on the network prefix and is notified. The pre-location registration request message including the care-of address and home address at the destination of the mobile router MR and the network prefix to be route optimized is transmitted to the address of the communication partner terminal CN2, and the communication partner terminal CN2 moves. The care-of address and home address of the mobile router MR Further, the communication partner terminal CN2 detects the packet reception on the new route after moving from the mobile router MR, or receives the movement completion notification from the mobile router MR, so that the mobile router When it is determined that the packet has moved, and a packet including the network prefix to be route optimized in the destination address is transmitted to the mobile router MR, the care-of address notified in advance is set as the destination address of the packet. Therefore, immediately after the movement between the terminal Node1 and the communication partner terminal CN2, even if the communication partner terminal CN is changed as viewed from the terminal Node1 accommodated in the mobile router MR, the shortest and optimum route is achieved without going through the home agent HA. Communication can be started.

Embodiment 8 FIG.
In the eighth embodiment, a case will be described in which a terminal accommodated in the mobile router MR communicates with a communication partner terminal that does not support the mobile IP protocol and communicates with a communication partner terminal that is different at the destination.

  FIG. 22 is a diagram illustrating a network configuration according to the eighth embodiment. The communication partner terminal CN of the terminal Node1 is CN1 in the wireless area Area # 1, and is CN2 in the wireless area Area # 2 after the movement. The IP address of CN1 is “C”, and the IP address of the new communication counterpart terminal CN2 is “E”. Further, proxy routers 10 and 11 for terminating the mobile IP protocol are provided in place of the communication counterpart terminals CN1 and CN2.

  FIG. 23 is a diagram showing a control sequence in the eighth embodiment. Next, the operation will be described. In FIG. 22, the mobile router MR that accommodates the terminal Node1 exists under the radio base station AP1, and the terminal Node1 is the communication counterpart terminal CN1 corresponding to the radio area Area # 1, the radio base station AP1, the access router AR1, and the proxy. Communication is performed via the router 10 without passing through the home agent HA (routes (5) and (9) in FIG. 22). The header configuration of the IP packet transferred between the terminal Node1 and the proxy router 10 when the mobile router MR is located under the radio base station AP1 (radio area Area # 1 = subordinate to the access router AR1) This is the same as (A) and (B) of FIG. 6 and (A) and (B) of FIG.

  On the other hand, for the packet between the communication partner terminal CN1 and the proxy router 10 indicated by the arrow (9) in FIG. 22, the communication partner terminal CN1 sets the destination address to the address “D” of the terminal Node1 and the communication partner to the transmission source address. A packet in which the address “C” of the terminal CN1 is set, while the proxy router 10 sends a packet in which the destination address is set to the address “C” of the communication partner terminal CN1 and the source address is set to the address “D” of the terminal Node1. Send. Further, for the packet between the terminal Node1 and the mobile router MR indicated by the arrow (4) in FIG. 22, the destination address is set to the address “C” of the communication partner terminal CN1 from the terminal Node1, and the address of the terminal Node1 is set to the source address The packet in which “D” is set is transferred from the mobile router MR to the address “D” of the terminal Node1 as the destination address and the packet “address” of the communication partner terminal CN1 as the source address.

  Next, the control sequence will be described with reference to FIG. The access router AR1 transmits a network prefix assigned to the interface line of the access router AR1 to which the radio base station AP1 is connected to the router advertisement message periodically transmitted to the subordinate terminal and the mobile router. 1), a network prefix assigned to the interface line of the access router AR2 to which the radio base station AP2 is connected (a prefix of the radio area Area # 2 to which the mobile router MR moves next), and a radio area Area # 2, including the address “E” of the communication partner terminal CN 2 in 2, the ID of the communication partner terminal CN 2 having a unique value in a plurality of areas, and the address “J” of the proxy router 11 corresponding to the communication partner terminal CN 2.

  The mobile router MR that has received this router advertisement message sends a pre-location registration request message to the communication partner terminal CN2 that is the communication partner of the terminal Node1 before moving to the wireless area Area # 2 (subordinate to the access router AR2). Send. This pre-location registration request and its response message correspond to the sequence of arrow (6) in FIG. In the mobile router MR, the correspondence relationship between the address “D” of the terminal Node1, its network prefix “F”, and the ID of the communication partner terminal CN that is the communication partner is set in advance. The mobile router MR searches the network prefix of the corresponding terminal Node1 from the ID included in the router advertisement, and transmits a pre-location registration request message to the address of the proxy router 11 included in the router advertisement message. The pre-location registration request message includes the home address “A” of the mobile router MR, the care-of address “Y” in the radio area Area # 2 that moves next, and the network prefix “F” of the subnet to which the terminal Node1 belongs.

  The proxy router 11 stores the correspondence relationship between the care-of address currently used by the terminal, the home address, and the network prefix, and the correspondence relationship between the care-of address, home address, and network prefix used after the terminal is moved. When the proxy router 11 receives the pre-location registration request message, the proxy router 11 includes the care-of address “Y” and the home address “included in the pre-location registration request message in the pre-location registration table. A ”and a set of optimization target network prefix“ F ”are set and stored.

  Further, the mobile router MR notifies the address “E” of the communication partner terminal CN2 included in the router advertisement message to the terminal Node1 corresponding to the ID.

  The mobile router MR receives the router advertisement including the network prefix of the radio area Area # 2 from the access router AR2 or detects the establishment of the radio link with the radio base station AP2 on the condition of the communication route. Switch to the communication path via the access router AR2. At that time, a movement notification message is transmitted to the terminal Node1. The terminal Node1 starts communication with the communication partner terminal CN2 when receiving the movement notification message. At that time, the header configuration of the IP packet transferred between the terminal Node1 and the proxy router 11 acting as the proxy of the communication partner terminal CN2 is the same as that in FIG. 6C, D, or FIG. Same as (C) and (D), but the address “C” becomes the address “E” of the communication partner terminal CN2.

  When the proxy router 11 corresponding to the communication partner terminal CN2 receives the packet of FIG. 6C or FIG. 9C from the mobile router MR, the mobile router MR and the terminal Node1 accommodated therein receive the wireless area Area. It is determined that it has moved to # 2, and the contents of the pre-location registration table are moved to the location registration table. Thereafter, for packets that include the network prefix “F” of the subnet to which the terminal Node1 belongs in the destination address, According to the contents, the address “E” is set as the transmission source address in the header configuration of FIG. 6D or FIG. 9D and transmitted.

  After the movement is completed, the mobile router MR transmits a location registration message including the set of the current care-of address and home address of the mobile router MR to the home agent HA, and notifies the home agent HA of the location change.

  Note that, as described with reference to FIG. 12 of the third embodiment, the mobile router MR immediately moves to the wireless area Area # 2 (subordinate to the radio base station AP2 = subordinate to the access router AR2). The proxy router 11 may determine that the mobile router MR and the terminal Node1 accommodated therein have moved to the wireless area Area # 2 upon reception of the movement completion notification.

  In the above description, the router advertisement includes the address and ID of the communication partner terminal CN2 at the destination of the node Node1, and the address “J” of the proxy router 11 corresponding to the communication partner terminal CN2. The communication partner terminal CN2 address, ID, proxy router 11 address) may be notified to the mobile router MR by another message. The home agent HA receives the location registration message from the mobile router MR, notifies the address information to the mobile router MR by a dedicated message or a location registration response message, and the mobile router MR sends the above information to the terminal Node1. You may make it notify address information.

  As described above, in the eighth embodiment, the access router AR uses the network prefix and destination necessary for generating a care-of address at the next destination of the mobile router MR in advance for the mobile router MR. Of the communication partner terminal CN2 of the terminal Node1, the ID of the communication partner terminal CN group that is a unique value in a plurality of areas, and the address of the proxy router 11 corresponding to the communication partner terminal CN2, the mobile router MR A care-of address is generated based on the network prefix, and a pre-location registration request including the care-of address at the destination of the mobile router MR, the home address, and the network prefix to be route optimized for the notified address of the proxy router 11 Send the message, and the proxy router 11 The care-of address of the mobile router MR, the home address, and the corresponding network prefix are stored, and the proxy router 11 detects packet reception on a new route after moving from the mobile router MR, or reports completion of movement from the mobile router MR. Upon reception, it is determined that the mobile router has moved to the wireless area, and when the packet including the network prefix subject to route optimization in the destination address is transmitted to the mobile router MR, the destination address of the packet is notified in advance. Since the care-of address is set, the communication partner terminal CN is changed between the terminal Node1 and the communication partner terminal CN2 that does not support the mobile IP protocol immediately after the movement as viewed from the terminal Node1 accommodated in the mobile router MR. Even if it becomes It is possible to start communication in the shortest and optimal route without passing through the chromatography beam agent HA.

Embodiment 9 FIG.
In the ninth embodiment, when the communication partner terminal CN of the mobile terminal MN is changed due to movement of the mobile terminal MN, route optimization for concealing the address change of the communication partner terminal CN from the mobile terminal MN will be described.

  The network configuration to which the ninth embodiment is applied is the same as that shown in FIG. FIG. 24 is a diagram illustrating a control message sequence according to the ninth embodiment. FIG. 25 is a diagram illustrating an address conversion method performed by the access router in order to conceal the address change of the communication partner terminal CN in the ninth embodiment.

  Next, the operation will be described. In FIG. 24, the access router AR1 stores a correspondence table of virtual addresses and real IP addresses as the address of the communication counterpart terminal CN, and in the router advertisement message periodically transmitted to the subordinate terminals, the radio base station Network prefix assigned to the interface line of the access router AR1 to which the AP1 is connected (prefix of the existing wireless area Area # 1) and network assigned to the interface line of the access router AR2 to which the wireless base station AP2 is connected The transmission is performed including the prefix (prefix of the radio area Area # 2 where the mobile terminal MN moves next) and the virtual address (anycast address) CN-A of the communication partner terminal CN.

  The mobile terminal MN that has received this router advertisement message stores CN-A as the address of the communication counterpart terminal CN2 after movement. Further, the mobile terminal MN transmits a pre-location registration request message to the communication partner terminal CN2 before moving to the radio area Area # 2 (subordinate to the access router AR2). At this time, the stored virtual address CN-A is used as the address of the communication partner terminal CN2.

  When the access router AR1 that has received the pre-location registration request message in which the virtual address CN-A is set as the destination address recognizes that the message type is “pre-location registration request”, as shown in FIG. The destination address of the prior location registration request message is changed from the virtual address CN-A to the IP address “E” of the communication partner terminal CN2, and transmitted to the communication partner terminal CN2. In the access router AR1, the address information “E” for converting the virtual address CN-A is acquired in advance when the prior location registration request message is received.

  Further, when the access router AR1 receives the advance location registration request message, the access router AR1 stores the address (care-of address “X” of the mobile terminal MN) included in the source address area of the advance location registration request message, and stores the destination. When a packet including the address “X” as an address is received, if it is detected that the packet is a pre-location registration response message, the source address is changed from “X” as shown in FIG. Change to “CN-A” and transmit to mobile terminal MN.

  Upon receiving the previous location registration request message from the access router AR1, the correspondent terminal CN2 receives the care-of address “Y” and the home address “included in the previous location registration request message in the previous location registration table corresponding to the mobile terminal MN. A set of “A” is set and stored.

  The mobile terminal MN receives the router advertisement including the network prefix of the radio area Area # 2 from the access router AR2, or detects the establishment of the radio link with the radio base station AP2 under the condition of the access router AR2 Communication with the communication partner terminal CN2 is started through the communication path via.

  When the access router AR2 receives a packet from the mobile terminal MN including the virtual address CN-A in the destination address toward the communication counterpart terminal CN2, as shown in FIG. 25A, the virtual address “CN-A” Is changed to the address “E” of the communication partner terminal CN2, and transmitted to the communication partner terminal CN2. Further, when the access router AR2 receives a packet including the address “E” of the communication partner terminal CN2 from the communication partner terminal CN2 in the transmission source address of the packet header, as shown in FIG. Is changed to the virtual address “CN-A” and transmitted to the mobile terminal MN. The packet between the mobile terminal and the communication partner terminal CN2 via the access router AR2 is the packet between the mobile terminal and the communication partner terminal CN2 via the access router AR2, since the care-of address of the mobile terminal MN is “Y”. In FIG. 25, the address “X” included in the source or destination address in FIGS. 25A and 25B is “Y”. In the access router AR2, the address “E” of the communication partner terminal CN2 corresponding to the virtual address CN-A is set in advance.

  When the communication partner terminal CN2 detects that a packet on a new route has been received from the mobile terminal MN, it moves the contents of the pre-location registration table to the location registration table. Thereafter, the location registration is performed for the mobile terminal MN. Create the header part according to the contents of the table.

  In the above description, the virtual address “CN-A” of the communication partner terminal CN is included in the router advertisement, but the virtual address “CN-A” is notified to the mobile terminal MN by another message. Anyway. In addition, the home agent HA may receive the location registration message from the mobile terminal MN, and notify the virtual address “CN-A” by a dedicated message. Furthermore, the virtual address “CN” is added to the location registration response message. -A "may be included. Furthermore, when the access router AR1 receives the pre-location registration request, when the next communication counterpart terminal CN differs depending on the moving direction of the mobile terminal MN when converting the virtual address CN-A, the mobile terminal MN Includes the flag indicating the moving direction or the change history information of the care-of address, and the access router AR1 specifies the moving destination of the mobile terminal MN from the information and transmits the communication partner at the moving destination. You may make it convert into the address of the terminal CN.

  As described above, in the ninth embodiment, the access router AR notifies the mobile terminal MN of the virtual address of the communication counterpart terminal CN, and in addition, the care-of address at the next destination of the mobile terminal MN in advance. The mobile terminal MN generates a care-of address based on the network prefix and generates a care-of address at the destination of the mobile terminal MN to the notified virtual address. The access router AR captures the pre-location registration request message including the home address with the address, converts the virtual address into the address of the communication partner terminal CN at the next destination, and communicates with the communication partner. To the terminal CN, and the communication partner terminal CN sends the care-of address and home address at the destination of the mobile terminal MN Further, the communication partner terminal CN determines that the communication route has been switched by detecting the reception of a packet on the new route after moving from the mobile terminal MN, so that the packet transmitted from the communication partner terminal CN to the mobile terminal MN The care-of address that has been notified in advance is set as the destination address, and the mobile terminal MN communicates with the communication partner terminal CN using the virtual address, but actually communicates with the virtual address at the access router. Since the address of the communication partner terminal CN is converted, the mobile terminal MN is not aware of the change of the communication partner terminal CN, and the mobile terminal MN and the communication partner terminal CN pass through the home agent HA immediately after the movement. Communication can be started with the shortest and optimum route.

Embodiment 10 FIG.
In the tenth embodiment, when the communication counterpart terminal CN of the terminal accommodated in the mobile router MR is changed due to the movement of the mobile router MR and the terminal, the communication counterpart terminal CN is communicated with the terminal accommodated in the mobile router MR. The route optimization for concealing the address change will be described.

  The network configuration to which the tenth embodiment is applied is the same as that shown in FIG. FIG. 26 is a diagram showing a sequence of control messages in the tenth embodiment. FIG. 27 is a diagram illustrating an address conversion method performed by the access router in order to conceal the address change of the communication partner terminal CN in the tenth embodiment.

  Next, the operation will be described. In FIG. 26, the mobile router MR holds in advance a correspondence table between the virtual address (anycast address) for the communication counterpart terminal CN and the terminal Node1, and the virtual address corresponding to the communication counterpart terminal CN is preliminarily or periodically stored in the terminal Node1. To be notified. At this time, the mobile router MR notifies the virtual address corresponding to the communication partner terminal CN to (a) a plurality of terminals Node, respectively, and (b) the plurality of terminals Node communicate with the same communication partner terminal CN. In such a case, notification is made by either a group multicast notification or (c) a notification to all the terminals Node all at once by broadcast.

  The operations of the access router AR1, mobile router MR, communication partner terminal CN2, and home agent HA are the same as those of the seventh embodiment except for the following points, and redundant description is omitted. The difference is that, when the mobile router MR moves to the wireless area Area # 2 (subordinate to the access router AR2) and receives a packet including the virtual address CN-A as the destination address from the terminal Node1, FIG. As shown in FIG. 4, the virtual address “CN-A” is changed to the address “E” of the communication partner terminal CN2 included in the router advertisement from the access router AR1, encapsulated by the outer capsule header, and passed through the access router AR1. While transmitting to the communication partner terminal CN2, as shown in FIG. 27B, the outer capsule header of the packet from the communication partner terminal CN2 is deleted, and the address of the communication partner terminal CN2 included in the transmission source address of the inner header “E” is changed to the virtual address “CN-A” and transmitted to the terminal Node1.

  As described above, in the tenth embodiment, the access router AR notifies the mobile router MR of the real address of the communication counterpart terminal CN2 at the next destination, and the mobile router MR is the next destination. A pre-location registration request message is transmitted to the communication partner terminal CN2, and the communication partner terminal CN2 stores the care-of address and home address at the destination of the mobile terminal MN, and detects packet reception on the new route after movement. Thus, it is determined that the communication path has been switched, and the care-of address that has been notified in advance is set as the destination address of the packet transmitted from the communication counterpart terminal CN2 to the terminal Node1 accommodated in the mobile router MR and accommodated in the mobile router MR. Terminal Node1 communicates with the communication partner terminal CN2 using the virtual address, but in the mobile router MR Since the address of the communication partner terminal CN2 that actually communicates with the virtual address is converted, the terminal Node1 accommodated in the mobile router MR is not aware of the address change of the communication partner terminal CN, and the terminal Node1 and the communication partner terminal CN can start communication immediately after moving on the shortest and optimum route without going through the home agent HA.

Embodiment 11 FIG.
In the eleventh embodiment, the radio coverage areas of two radio systems (radio systems A and B) overlap, and the radio area of one radio system A (hereinafter abbreviated as radio A) is continuous so as to be in contact with the adjacent area. If the wireless area of the other wireless system B (hereinafter abbreviated as “radio B”) is discontinuously arranged in a spot-like manner (intermittently), Only the route optimization when the terminal accommodated in the mobile router MR or the mobile terminal MN communicates with the communication partner terminal CN will be described. For example, the wireless system A is a narrowband communication system, and the wireless system B is a broadband communication system.

  FIG. 28 is a diagram showing a network configuration in the eleventh embodiment. In FIG. 28, the mobile router MR has a wireless base station AP1 in the area # A1 of the wireless system A, a wireless base station AP3 in the area Area # B1 of the wireless system B, and an area Area # A2 of the wireless system A. Can communicate with the wireless base station AP2 and the wireless base station AP4 within the area # B2 of the wireless system B, and the terminal Node1 accommodated in the mobile router MR can communicate with the communication partner terminal CN and the wireless B area Area. Communication is performed only within # B1 and Area # B2. The radio base stations AP1 and AP3 are connected to the access router AR1, and the radio base stations AP2 and AP4 are connected to the access router AR2. FIG. 29 shows a control message sequence in the eleventh embodiment.

  Next, the operation will be described. In FIG. 28, the mobile router MR that accommodates the terminal Node1 initially exists under the radio A radio base station AP1. At that time, as shown in FIG. 29, the access router AR1 that accommodates the wireless base station AP1 of the wireless A periodically transmits the network prefix assigned to the interface line connected to the wireless base station AP1 A wireless area Area # A1 prefix), the network prefix assigned to the interface line of the access router AR2 to which the adjacent wireless base station AP2 of the wireless A is connected (the wireless area Area of the wireless A to which the mobile router MR moves next) # A2 prefix) and the network prefix of wireless area Area # B1 of wireless B to be moved next are broadcast by router advertisement.

  The mobile router MR that has received this router advertisement message sets an optimized communication path between the subordinate Node1 and the communication partner terminal CN before moving to Area # B1 (subordinate to the radio base station AP3) of the radio B. Therefore, the wireless B area # B1 pre-position registration request message is transmitted to the communication counterpart terminal CN via the wireless A wireless base station AP1 and the access router AR1. In the mobile router MR, the address “D” of Node1, the network prefix “F”, and the address “C” of the communication partner terminal CN are set in advance. The pre-location registration request message includes the home address “A” of the mobile router MR, the care-of address “J” of the mobile router MR in the radio area Area # B1 of the radio B, and the prefix “F” of the network to which the terminal Node1 belongs. .

  In addition, the mobile router MR registers the location of the wireless area Area # A1 of the wireless A with the home agent HA. This location registration message includes the home address “A” of the mobile router MR, the care-of address “X” of the mobile router MR in the radio area Area # A1 of the radio A, and the prefix “F” of the subordinate network.

  When receiving the above-mentioned pre-location registration request message, the correspondent terminal CN sets and stores the care-of address “J”, the home address “A”, and the corresponding network prefix “F” in the pre-location registration table.

  When the mobile router MR moves and reaches within the wireless B area Area # B1, a wireless B connection notification connected to the mobile router MR is transmitted to the mobile router MR. When receiving the wireless B connection notification, the mobile router MR transmits a connection notification to the terminal Node1.

  When receiving the connection notification from the mobile router MR, the terminal Node1 starts communication with the communication partner terminal CN. When the mobile router MR receives a packet addressed to the communication counterpart terminal CN from the terminal Node1, the mobile router MR transfers the packet to the communication counterpart terminal CN via the radio base station AP3 and the access router AR1. At that time, the header configuration of the IP packet transferred from the mobile router MR to the correspondent terminal CN is the same as that in FIG. 6A or FIG. 9A used in the second embodiment. However, in this case, the address “X” of the transmission source address of the outer header is the care-of address “J” in the radio area Area # B1 of the radio B of the mobile router MR.

  When receiving the packet of FIG. 6 (A) or FIG. 9 (A), the correspondent terminal CN has received the care-of address (in this case, “J”) for the mobile router MR stored in the pre-location registration table. Based on the match with the source address (in this case, “J”) set in the source address area of the header of the packet, the mobile router MR determines that the mobile router MR has moved to the wireless B area # B1, and the mobile router When the packet is further transferred to the MR and the terminal Node1, the IP packet shown in FIG. 6B or 9B is generated and transmitted. In this case, the address “X” of the destination address of the outer header is the address “J”.

  With such an IP header, the mobile router MR can directly communicate with the communication counterpart terminal CN via the radio base station AP3 and the access router AR1 without going through the home agent HA.

  Note that the mobile router MR registers the location of the wireless B wireless area Area # B1 with the home agent HA. This location registration message includes the home address “A” of the mobile router MR, the care-of address “J” of the mobile router MR in the radio area Area # B1 of the radio B, and the prefix “F” of the network to which the terminal Node1 belongs.

  On the other hand, when the mobile router MR moves and deviates from the wireless B wireless area Area # B1, a wireless B disconnection notification is transmitted to the mobile router MR from a wireless device compatible with the wireless B connected to the mobile router MR. The When receiving the wireless B disconnect notification, the mobile router MR transmits a disconnect notification to the terminal Node1. When receiving the disconnection notice, the terminal Node1 stops packet transfer to the communication partner terminal CN via the wireless B.

  The mobile router MR moves from the radio area Area # B1 of the radio B to the home agent HA and the counterpart terminal CN using the radio A (via the radio base station AP1 and the access router AR1). In order to indicate that wireless B communication is disabled, a location registration cancellation message is transmitted. In these location registration cancellation messages, it is assumed that the valid time (Life Time) area included in the message is set to zero.

  After the mobile router MR is connected to the wireless B, the access router AR1 transmits the network prefix and the next destination (wireless) in the wireless B wireless area Area # B1 via the wireless B wireless base station AP3. A router advertisement including a network prefix in B wireless area Area # B2) is periodically transmitted.

  The mobile router MR that receives the router advertisement in the wireless area Area # B1 of the wireless B stores the network prefix in the next destination of the next wireless B (the wireless area Area # B2 of the wireless B), and stores the wireless prefix. After receiving the B disconnect notification, pre-location registration including a care-of address at the next destination (wireless B wireless area Area # B2) to the communication counterpart terminal CN via wireless A (wireless base station AP1, access router AR1) Send a message. In this pre-location registration message, the care-of address “K” of the mobile router MR in the radio area Area # B2 of the radio B (this address is generated from the network prefix of the router advertisement and the MAC address of the mobile router MR), the mobile The home address “A” of the router MR and the prefix “F” of the network to which the terminal Node1 belongs are included.

  When the communication partner terminal CN receives the prior location registration request message, it sets and stores the care-of address “K”, home address “A”, and corresponding network prefix “F” in the prior location registration table.

  In addition, the mobile router MR uses the network prefix at the next destination of the wireless A (the wireless area Area # A2 of the wireless A) included in the router advertisement received from the access router AR1 via the wireless A in the wireless area Area # A2. And a location registration message is transmitted to the home agent HA including the home address “A” of the mobile router MR.

  When the mobile router MR moves further and reaches within the wireless B wireless area Area # B2, a wireless B connection notification connected to the mobile router MR is transmitted to the mobile router MR. . Upon receiving the wireless B connection notification, the mobile router MR transmits a connection notification to the terminal Node1.

  When receiving the connection notification from the mobile router MR, the terminal Node1 starts communication with the communication partner terminal CN. When the mobile router MR receives a packet addressed to the communication counterpart terminal CN from the terminal Node1, the mobile router MR transfers the packet to the communication counterpart terminal CN via the radio base station AP4 and the access router AR2. At that time, the header configuration of the IP packet transferred from the mobile router MR to the correspondent terminal CN is the same as that in FIG. 6A or FIG. 9A used in the second embodiment. However, in this case, the address “X” of the transmission source address of the outer header is the care-of address “K” in the radio area Area # B2 of the radio B of the mobile router MR.

  When receiving the packet of FIG. 6 (A) or FIG. 9 (A), the correspondent terminal CN has received the care-of address (in this case, “K”) for the mobile router MR stored in the pre-location registration table. Based on the match with the transmission source address (in this case, “K”) set in the transmission source address area of the header of the packet, the mobile router MR determines that it has moved to the wireless area Area # B2 of the wireless B, and the mobile router When the packet is further transferred to the MR and the terminal Node1, the IP packet shown in FIG. 6B or 9B is generated and transmitted. In this case, the address “X” of the destination address of the outer header is the address “K”.

  With such an IP header, the mobile router MR can directly communicate with the communication counterpart terminal CN via the radio base station AP4 and the access router AR2 without going through the home agent HA.

  The mobile router MR registers the location of the wireless B area # B2 with the home agent HA. This location registration message includes the home address “A” of the mobile router MR, the care-of address “K” of the mobile router MR in the radio area Area # B2 of the radio B, and the prefix “F” of the network to which the terminal Node1 belongs.

  Thereafter, when the mobile router MR moves and deviates from the wireless B wireless area Area # B2, a wireless B disconnection notification is transmitted to the mobile router MR from the wireless device corresponding to the wireless B connected to the mobile router MR. When receiving the wireless B disconnect notification, the mobile router MR transmits a disconnect notification to the terminal Node1. When receiving the disconnection notice, the terminal Node1 stops packet transfer to the communication partner terminal CN via the wireless B.

  Note that the communication partner terminal CN may determine that the communication path has been switched by receiving the movement completion notification from the mobile router MR.

  As described above, in the eleventh embodiment, the area of the wireless system A in which the mobile router MR can always communicate and the area of the wireless system B in which the areas are discontinuously arranged and perform spot communication overlap in the same place. In the wireless system arranged as described above, the access router AR notifies the mobile router MR using the wireless A or the wireless B in advance of the network prefix necessary for generating the care-of address in the area of the wireless B. The router MR generates a care-of address in the area of the wireless B based on the network prefix, and optimizes the communication between the terminal Node1 and the communication partner terminal CN with respect to the communication partner terminal CN that is the communication destination of the subordinate terminal Node1. In order to set the communication path, the care-of address in the wireless B area, the home address of the mobile router MR , And a pre-location registration request message including the network prefix of the subnet to which the terminal Node1 belongs, using the wireless A, and in the communication partner terminal CN, the care-of address and home address at the destination of the mobile router MR, and route optimization The target network prefix is stored in memory, and the communication partner terminal CN receives a packet having the care-of address after movement from the mobile router MR in the transmission source address area, so that the communication path is cut off as the mobile router MR moves. Since it is determined that the packet has been changed, the packet sent to the address having the network prefix to be route-optimized is switched to the care-of address after movement that stores the care-of address set as the destination address. Contained in MR Immediately after movement between the correspondent terminal CN and terminal Node1 is, without going through the home agent HA, it is possible to continue the communication in the shortest path.

Embodiment 12 FIG.
In the eleventh embodiment, the route optimization method in the case where the communication partner terminal CN of the terminal Node1 is one has been described. However, in the twelfth embodiment, as in the eleventh embodiment, the radios of the two radio systems A and B are used. A description will be given of route optimization in a case where the communication partner terminal CN of the terminal Node1 is different for each destination in the wireless system in which the cover areas overlap.

  FIG. 30 is a diagram illustrating a network configuration according to the twelfth embodiment. In FIG. 30, the mobile router MR has a radio base station AP1 in the area # A1 of the radio A, a radio base station AP3 in the area Area # B1 of the radio B, and a radio base station in the area Area # A2 of the radio A. In the area Area # B2 of the wireless B, the AP 2 can communicate with the wireless base station AP4, and the terminal Node1 accommodated in the mobile router MR is the communication partner terminal CN and the areas Area # B1 and Area # B2 of the wireless B. Communicate only within. However, the terminal Node1 communicates with the communication partner terminal CN1 in the area B of the wireless B and the communication partner terminal CN2 in the area Area # B2 of the wireless B. FIG. 31 shows a control message sequence in the twelfth embodiment.

  Next, the operation will be described. In FIG. 30, the mobile router MR that accommodates the terminal Node1 initially exists under the radio A radio base station AP1. At that time, as shown in FIG. 31, the access router AR1 that accommodates the wireless base station AP1 of the wireless A periodically repeats the prefix of the wireless area Area # A1 of the wireless A that is in the area, and the next movement destination of the wireless A. The prefix of the wireless area Area # A2, the prefix of the wireless area Area # B1 that is the next destination of the wireless B, and the address of the communication counterpart terminal CN1 in the wireless area Area # B1 are broadcast by router advertisement.

  The mobile router MR that has received this router advertisement message notifies the address of the communication partner terminal CN1 to the terminal Node1, and before moving to the wireless B area # B1 (subordinate to the wireless base station AP3), In order to set an optimized communication path between the subordinate Node1 and the communication partner terminal CN1, a wireless B area # B1 pre-position registration request message is transmitted to the communication partner terminal CN1, the wireless base station AP1 of the wireless A, and the access router AR1. To send through. The pre-location registration request message includes the home address “A” of the mobile router MR, the care-of address “J” of the mobile router MR in the radio area Area # B1 of the radio B, and the prefix “F” of the network to which the terminal Node1 belongs. include.

  In addition, the mobile router MR registers the location of the wireless area Area # A1 of the wireless A with the home agent HA. This location registration message includes the home address “A” of the mobile router MR, the care-of address “X” of the mobile router MR in the radio area Area # A1 of the radio A, and the prefix “F” of the subordinate network.

  Upon receiving the pre-location registration request message, the communication partner terminal CN1 sets and stores the care-of address “J”, the home address “A”, and the corresponding network prefix “F” in the pre-location registration table.

  When the mobile router MR moves and reaches within the wireless B area Area # B1, a wireless B connection notification connected to the mobile router MR is transmitted to the mobile router MR. When receiving the wireless B connection notification, the mobile router MR transmits a connection notification to the terminal Node1.

  When receiving the connection notification from the mobile router MR, the terminal Node1 starts communication with the communication partner terminal CN1. When the mobile router MR receives a packet addressed to the communication counterpart terminal CN1 from the terminal Node1, the mobile router MR transfers the packet to the communication counterpart terminal CN1 via the radio base station AP3 and the access router AR1. At that time, the header configuration of the IP packet transferred from the mobile router MR to the communication partner terminal CN1 is the same as that in FIG. 6A or FIG. 9A used in the second embodiment, as in the eleventh embodiment. It is. However, in this case, the address “X” of the transmission source address of the outer header is the care-of address “J” in the radio area Area # B1 of the radio B of the mobile router MR.

  Similarly to the eleventh embodiment, when the communication partner terminal CN1 receives the packet of FIG. 6 (A) or FIG. 9 (A), the care-of address for the mobile router MR (in this case, “ J ") and the match between the source address set in the source address area of the header part of the received packet (in this case," J "), the mobile router MR moves to radio area Area # B1 of radio B When the packet is transferred to the mobile router MR and the terminal Node1, the IP packet shown in FIG. 6B or FIG. 9B is generated and transmitted. In this case, as in the eleventh embodiment, the address “X” of the destination address of the outer header is the address “J”.

  With such an IP header, the mobile router MR can directly communicate with the communication counterpart terminal CN1 via the radio base station AP3 and the access router AR1 without going through the home agent HA.

  Note that the mobile router MR registers the location of the wireless B wireless area Area # B1 with the home agent HA. This location registration message includes the home address “A” of the mobile router MR, the care-of address “J” of the mobile router MR in the radio area Area # B1 of the radio B, and the prefix “F” of the network to which the terminal Node1 belongs.

  On the other hand, when the mobile router MR moves and deviates from the wireless B wireless area Area # B1, a wireless B disconnection notification is transmitted to the mobile router MR from a wireless device compatible with the wireless B connected to the mobile router MR. The When receiving the wireless B disconnect notification, the mobile router MR transmits a disconnect notification to the terminal Node1. When receiving the disconnection notice, the terminal Node1 stops packet transfer to the communication partner terminal CN via the wireless B.

  The mobile router MR moves from the wireless area Area # B1 of the wireless B to the home agent HA and the counterpart terminal CN1 using the wireless A (via the wireless base station AP1 and the access router AR1). In order to indicate that wireless B communication is disabled, a location registration cancellation message is transmitted.

  After the mobile router MR is connected to the wireless B, the access router AR1 transmits the network prefix in the wireless area Area # B1 of the wireless B and the next destination (wireless B) via the wireless base station AP3 of the wireless B. Router advertisement including the network prefix in the wireless area Area # B2) and the address of the communication partner terminal CN2 in the wireless B next destination (wireless area Area # B2).

  The mobile router MR that has received the router advertisement in the wireless area Area # B1 of the wireless B notifies the terminal Node1 of the address of the communication partner terminal CN2 in the wireless area Area # B2 next to the wireless B. The care-of address “K” in the wireless area Area # B2 is generated from the network prefix at the next destination of the wireless B (the wireless area Area # B2 of the wireless B), and the wireless A (wireless Via the base station AP1 and the access router AR1), a pre-location registration message including the care-of address “K” at the next destination (the radio area Area # B2 of the radio B) is transmitted to the communication counterpart terminal CN2. In this pre-location registration message, the care-of address “K” of the mobile router MR in the radio area Area # B2 of the radio B (this address is generated from the network prefix of the router advertisement and the MAC address of the mobile router MR), the mobile The home address “A” of the router MR and the prefix “F” of the network to which the terminal Node1 belongs are included.

  When the communication partner terminal CN receives the prior location registration request message, it sets and stores the care-of address “K”, home address “A”, and corresponding network prefix “F” in the prior location registration table.

  In addition, the mobile router MR uses the network prefix at the next destination of the wireless A (the wireless area Area # A2 of the wireless A) included in the router advertisement received from the access router AR1 via the wireless A in the wireless area Area # A2. And a location registration message is transmitted to the home agent HA including the home address “A” of the mobile router MR.

  When the mobile router MR moves further and reaches within the wireless B wireless area Area # B2, a wireless B connection notification connected to the mobile router MR is transmitted to the mobile router MR. . Upon receiving the wireless B connection notification, the mobile router MR transmits a connection notification to the terminal Node1.

  When receiving the connection notification from the mobile router MR, the terminal Node1 starts communication with the communication partner terminal CN2. When the mobile router MR receives a packet addressed to the communication counterpart terminal CN2 from the terminal Node1, the mobile router MR transfers the packet to the communication counterpart terminal CN2 via the radio base station AP4 and the access router AR2. At that time, the header configuration of the IP packet transferred from the mobile router MR to the communication counterpart terminal CN is the same as that in FIG. 6A or FIG. 9A used in the second embodiment, as in the eleventh embodiment. It is. However, in this case, the address “X” of the transmission source address of the outer header is the care-of address “K” in the radio area Area # B2 of the radio B of the mobile router MR, and the address “C” of the communication partner terminal CN is the communication The address “E” of the partner terminal CN2 is obtained.

  When receiving the packet of FIG. 6 (A) or FIG. 9 (A), the correspondent terminal CN2 has received the care-of address (in this case, “K”) for the mobile router MR stored in the pre-location registration table. Based on the match with the transmission source address (in this case, “K”) set in the transmission source address area of the header of the packet, the mobile router MR determines that it has moved to the wireless area Area # B2 of the wireless B, and the mobile router When the packet is further transferred to the MR and the terminal Node1, the IP packet shown in FIG. 6B or 9B is generated and transmitted. In this case, the address “X” of the destination address of the outer header is the address “K”, and the address “C” of the communication partner terminal CN is the address “E” of the communication partner terminal CN2.

  With such an IP header, the mobile router MR can directly communicate with the communication counterpart terminal CN2 via the radio base station AP4 and the access router AR2 without going through the home agent HA.

  The mobile router MR registers the location of the wireless B area # B2 with the home agent HA. This location registration message includes the home address “A” of the mobile router MR, the care-of address “K” of the mobile router MR in the radio area Area # B2 of the radio B, and the prefix “F” of the network to which the terminal Node1 belongs.

  Thereafter, when the mobile router MR moves and deviates from the wireless B wireless area Area # B2, a wireless B disconnection notification is transmitted to the mobile router MR from the wireless device corresponding to the wireless B connected to the mobile router MR. When receiving the wireless B disconnect notification, the mobile router MR transmits a disconnect notification to the terminal Node1. When receiving the disconnection notice, the terminal Node1 stops packet transfer to the communication partner terminal CN via the wireless B.

  The communication partner terminals CN1 and CN2 may determine that the communication path has been switched by receiving the movement completion notification from the mobile router MR.

  As described above, in the twelfth embodiment, the area of the wireless system A in which the mobile router MR can always communicate and the area of the wireless system B in which the areas are discontinuously arranged and perform spot communication overlap in the same place. If the communication counterpart terminal CN of the terminal Node1 under the mobile router MR is different in the movement destination area in the wireless system arranged in this manner, the access router AR uses the wireless A or the wireless B in advance to the mobile router MR. , The network prefix necessary for generating the care-of address in the wireless B area and the address of the communication partner terminal CN at the moving destination are notified, and the mobile router MR determines the care-of address in the wireless B area based on the network prefix. For the address of the communication partner terminal CN that has been generated and notified, A pre-location registration request message including the network address of the mobile router MR, the home address of the mobile router MR, and the network prefix of the subnet to which the terminal Node1 belongs is transmitted using the wireless A, and the communication partner terminal CN notices at the destination of the mobile router MR An address, a home address, and a network prefix to be route optimized are stored, and the communication partner terminal CN determines that the communication route has been switched along with the movement of the mobile router MR based on the movement detection on the mobile router MR side. Since the care-of address set as the destination address is switched to the care-of address after the movement for the packet transmitted to the address having the network prefix to be route-optimized, the terminal Node1 accommodated in the mobile router MR communication Immediately after movement between the hand terminal CN, without passing through the home agent HA, it is possible to continue the communication in the shortest and optimal route.

Embodiment 13 FIG.
In the twelfth embodiment, the case where the areas of the wireless system B are discontinuously arranged in spots is shown. However, in the thirteenth embodiment, a plurality of areas of the wireless system B are continuously arranged in places. The route optimization between the terminal Node1 under the mobile router MR and the communication counterpart terminals CN1 and CN2 will be described.

  FIG. 32 is a diagram illustrating a network configuration according to the thirteenth embodiment. The mobile router MR is a radio base station AP1 in the area # A1 of the radio A, a radio base station AP3-1 in the area # B1-1 of the radio B, and a radio base station in the area # B1-2 of the radio B. AP 3-2, radio base station AP2 in area # A2 of radio A, radio base station AP4-1 in area # B2-1 of radio B, and radio base station in area # B2-2 of radio B Each of the nodes Node1 that can communicate with the AP4-2 and is accommodated in the mobile router MR is a communication partner terminal CN and areas B #, B # 1, B # 2, A # of the area B of the wireless B. Communicate only within B2-2. However, the terminal Node1 communicates with the communication partner terminal CN1 in the areas B # 1 and Area # B1-2 of the wireless B, and with the communication partner terminal CN2 in the areas Area # B2-1 and Area # B2-2 of the wireless B. . FIG. 33 shows a control message sequence in the thirteenth embodiment.

  Next, the operation will be described. In FIG. 32, the mobile router MR accommodating the terminal Node1 initially exists under the radio base station AP1 of the radio A, moves within the area A # of the radio A, and the area Area # B1- of the radio B. Suppose you move to 1, # B1-2. The area A # A1 of the wireless A overlaps the areas of the areas B # 1 and # B1-2 of the wireless B, and is accessed using the wireless A while communicating with the wireless B. It is possible to communicate with the router AR1, the home agent HA, or other devices in the network. Thereafter, the mobile router MR moves under the control of the wireless base station AP2 of the wireless A, and further moves to areas Area # B2-1 and # B2-2 of the wireless B. The area A # A2 of the wireless A overlaps with the areas Area # B2-1 and # B2-2 of the wireless B.

  The access router AR1 that accommodates the radio base station AP1 of the radio A periodically prefixes the area A # of the radio A that is in the area, the prefix of the area Area # A2 that moves next to the radio A, and the area of the radio B The prefix in Area # B1-1 and the address “C” of communication partner terminal CN1 in Area # B1-1 are broadcast by router advertisement.

  The mobile router MR that has received this router advertisement message notifies the address of the communication counterpart terminal CN1 to the terminal Node1 and moves to the area B # 1 of the wireless B (subordinate to the wireless base station AP3-1). Before, the wireless B area # B1-1 pre-location registration request message is transmitted to the address of the notified communication partner terminal CN1 via the wireless A wireless base station AP1 and the access router AR1. This pre-location registration request message includes the home address “A” of the mobile router MR, the care-of address “J” of the mobile router MR in the area B # of the wireless B, and the prefix “F” of the network to which the terminal Node1 belongs. Include.

  The mobile router MR registers the location of the area A # A1 of the wireless A with the home agent HA. This location registration message includes the home address “A” of the mobile router MR, the care-of address “X” of the mobile router MR in the area A # A1 of the radio A, and the prefix “F” of the subordinate network.

  Upon receiving the pre-location registration request message, the communication partner terminal CN1 sets and stores the care-of address “J”, the home address “A”, and the corresponding network prefix “F” in the pre-location registration table.

  When the mobile router MR moves and reaches within the wireless B wireless area Area # B1-1, the wireless B compatible area connected to the mobile router MR transmits the wireless B area Area # B1- A connection notification to 1 is sent. When the mobile router MR receives the connection notification of the wireless area Area # B1-1, the mobile router MR transmits a connection notification to the terminal Node1.

  When receiving the connection notification from the mobile router MR, the terminal Node1 starts communication with the communication partner terminal CN1. When the mobile router MR receives a packet addressed to the communication counterpart terminal CN1 from the terminal Node1, the mobile router MR transfers the packet to the communication counterpart terminal CN1 via the radio base station AP3-1 and the access router AR1. At that time, the header configuration of the IP packet transferred from the mobile router MR to the communication counterpart terminal CN1 is the same as that of the twelfth embodiment.

  Similarly to the twelfth embodiment, when the communication partner terminal CN1 receives a packet from the terminal Node1, the mobile router MR (terminal Node1) has a wireless B wireless area Area # B1- based on the stored contents of the pre-location registration table. When the mobile router MR is further transferred to the terminal Node1, the stored content of the updated location registration table is updated. An IP packet corresponding to is generated and transmitted.

  With such an IP header, the mobile router MR can directly communicate with the communication counterpart terminal CN1 via the radio base station AP3-1 and the access router AR1 without going through the home agent HA.

  Note that the mobile router MR registers the location of the wireless B wireless area Area # B1-1 with the home agent HA. The location registration message includes the home address “A” of the mobile router MR, the care-of address “J” of the mobile router MR in the radio area Area # B1-1 of the radio B, and the prefix “F” of the network to which the terminal Node1 belongs. include.

  After the mobile router MR has moved to the wireless area Area # B1-1, the access router AR1 transmits the network prefix in the wireless B wireless area Area # B1-1 via the wireless B wireless base station AP3-1. A router advertisement including a network prefix in the next movement destination (wireless B wireless area Area # B1-2) is periodically transmitted.

  The mobile router MR that has received this router advertisement generates a care-of address “L” from the network prefix in the next destination (wireless B Area # B1-2), and wireless A (wireless A base station AP1, access router AR1). ), A pre-location registration message including the care-of address “L” in area Area # B1-2 of wireless B, which is the next destination, is transmitted to communication partner terminal CN1. This pre-location registration message includes the care-of address “L” of the mobile router MR, the home address “A” of the mobile router MR, and the prefix “F” of the network to which the terminal Node 1 belongs in the area B # of the wireless B. Including.

  Upon receiving the prior location registration request message, the communication partner terminal CN1 sets and stores the care-of address “L”, the home address “A”, and the corresponding network prefix “F” in the prior location registration table.

  When the mobile router MR moves from the area B # 1 of the wireless B to the area Area # B1-2, the wireless B area connected to the mobile router MR is connected to the area B of the wireless B from the wireless router MR. A notification of connection to Area # B1-2 is transmitted.

  The mobile router MR transfers the packet addressed to the communication counterpart terminal CN1 through the route between the radio base station AP3-2 and the access router AR1 when receiving the connection notification. At that time, the header configuration of the IP packet transferred from the mobile router MR to the communication counterpart terminal CN1 is the same as that of the twelfth embodiment.

  When receiving the packet having the new care-of address “L” as the transmission source address from the mobile router MR, the communication counterpart terminal CN1 recognizes that the route has been changed from the stored contents of the pre-location registration table, and the terminal under the mobile router MR When a packet addressed to the prefix “F” to which Node1 belongs is received, the packet is transmitted to a new care-of address “L”.

  Note that the mobile router MR registers the location of the wireless B wireless area Area # B1-2 with the home agent HA. The location registration message includes the home address “A” of the mobile router MR, the care-of address “L” of the mobile router MR in the radio area Area # B1-2 of the radio B, and the prefix “F” of the network to which the terminal Node1 belongs. include.

  After the mobile router MR has moved to the radio area Area # B1-2, the access router AR1 transmits the network prefix in the radio B radio area Area # B1-2 via the radio B radio base station AP3-2. A router advertisement including the network prefix at the next destination (wireless area Area # B2-1 of the wireless B) and the address “E” of the communication partner terminal CN2 in the area Area # B2-1 is periodically transmitted.

  The mobile router MR that has received this router advertisement generates a care-of address “K” from the network prefix in the next destination (wireless B area Area # B2-1), and The address “E” of the communication partner terminal CN2 at the destination is transmitted.

  On the other hand, when the mobile router MR moves out of the area B of the wireless B due to the movement of the mobile router MR, an area # B1 of the wireless B is connected to the mobile router MR from the wireless apparatus corresponding to the wireless B connected to the mobile router MR. -2 disconnect notification is sent. When the mobile router MR receives the Area B B1-2 disconnection notification of the wireless B, the mobile router MR transmits a disconnection notification to the terminal Node1. When receiving the disconnection notification, the terminal Node1 stops packet transfer to the communication partner terminal CN1 via the wireless B.

  Further, the mobile router MR uses the wireless A (via the wireless base station AP1 and the access router AR1) to the home agent HA and the communication partner terminal CN1, respectively, for the wireless B Area # B1-2. The location registration cancellation message is transmitted to indicate that wireless B communication is disabled. Next, when the mobile router MR detects that it has moved to the wireless A area # A2 by, for example, a connection notification from a wireless device compatible with the wireless A (not shown), the mobile router MR Register the location of area Area # A2. This location registration message includes the home address “A” of the mobile router MR, the care-of address “Y” of the mobile router MR in the area A # of the wireless A, and the prefix “F” of the subordinate network.

  Thereafter, the mobile router MR sends the care-of address “in the area B # of the wireless B that is the next destination to the communication destination terminal CN2 via the wireless A (the base station AP1 of the wireless A, the access router AR1)“ A pre-location registration message including “K” is transmitted. This pre-location registration message includes the care-of address “K” of the mobile router MR, the home address “A” of the mobile router MR, and the prefix “F” of the network to which the terminal Node 1 belongs in the area B # of the wireless B. Including.

  Upon receiving the prior location registration request message, the communication partner terminal CN2 sets and stores the care-of address “K”, the home address “A”, and the corresponding network prefix “F” in the prior location registration table.

  When the mobile router MR moves and reaches within the area B # 2 of the wireless B, the wireless B compatible radio connected to the mobile router MR transmits the area # B2-1 of the wireless B to the mobile router MR. Connection notification is sent. When receiving the connection notification, the mobile router MR transmits a connection notification to the terminal Node1.

  When receiving the connection notification from the mobile router MR, the terminal Node1 starts communication with the communication partner terminal CN2. When receiving the packet addressed to the communication counterpart terminal CN2, the mobile router MR transfers the packet to the communication counterpart terminal CN2 via the radio base station AP4-1 and the access router AR2. The configuration of the packet header transferred between the terminal Node1, the mobile router MR, and the communication counterpart terminal CN2 at that time is the same as that of the twelfth embodiment. However, the address “E” of the communication partner terminal CN2 is set in the portion where the address of the communication partner terminal CN is stored (address “C” is stored).

  When receiving the packet having the new care-of address as the transmission source address from the mobile router MR, the communication counterpart terminal CN2 recognizes that the route has been changed based on the stored contents of the pre-position registration table, and the communication partner terminal CN2 When a packet addressed to the prefix “F” to which the packet belongs is received, the packet is transmitted to a new care-of address “K”.

  In the area of the wireless B Area # B2-1, the access router AR1 transmits the network prefix and the next destination (wireless) in the wireless B wireless area Area # B2-2 via the wireless B wireless base station AP4-1. A router advertisement including a network prefix in B wireless area Area # B2-2) is periodically transmitted.

  The mobile router MR that has received this router advertisement generates a care-of address “M” from the network prefix at the next destination (wireless B area Area # B2-2), and communicates with the communication partner terminal via the wireless base station AP2. A prior location registration message is transmitted to CN2. This pre-location registration message includes the care-of address “M” of the mobile router MR, the home address “A” of the mobile router MR, and the prefix “F” of the network to which the terminal Node 1 belongs in the area B # of the wireless B. Including.

  Also, the mobile router MR sends the care-of address “Y” in the area B # of the wireless B to the home agent HA, the home address “A” of the mobile router MR, and the network prefix “F” corresponding to the care-of address. Is sent so that a packet including the corresponding network prefix “F” in the destination address can be transferred to the corresponding care-of address “Y”.

  When the mobile router MR moves further and moves into the area of the wireless B area Area # B2-2, an area # 2-2 connection notification is transmitted from the wireless wireless device of the wireless B. , Communication is started using the care-of address “M” used in Area # B2-2.

  As described above, in the thirteenth embodiment, the wireless system A in which the mobile router MR can always communicate and the wireless system B in which the areas are discontinuously disposed and perform spot-like communication are overlapped at the same place. If the wireless system B is locally and continuously arranged, the access router AR uses the wireless A or the wireless B in advance to the mobile router MR and uses the area # B1 of the nearest wireless B. The mobile router MR generates a care-of address in the area # B1-1 of the wireless B based on this network prefix and sends it to the address of the communication partner terminal CN. On the other hand, the care-of address in the area of the wireless B, the home address of the mobile router MR, and the net of the subnet to which the terminal Node1 belongs A pre-location registration request message including the network prefix is transmitted using the wireless A, and the communication partner terminal CN stores the care-of address and home address at the destination of the mobile router MR, and the network prefix to be route optimized In addition, it is determined that the communication route has been switched with the movement of the mobile router MR from the packet reception detection on the new route after moving from the mobile router MR, and is transmitted to the address having the network prefix to be route optimized. For the packet to be transmitted, since the care-of address after the movement storing the care-of address set as the destination address is switched, the terminal Node1 accommodated in the mobile router MR and the communication partner terminal CN immediately after the movement, Without going through Agent HA Communication can be continued with a short path. Further, in the area # B1-1 of the wireless B, since the care-of address used in the adjacent area # B1-2 is notified in advance to the communication counterpart terminal CN by the prior position registration message, the spot communication sections are continuous. Even in this case, communication can be continued on the shortest path immediately after the movement without going through the home agent HA.

  In the above description, the access router notifies the network prefix at the destination by the router advertisement, but may be notified by a dedicated message including the network prefix at the destination.

  As described above, the wireless communication system according to the present invention is useful for a system in which communication is performed between a mobile terminal and a communication partner terminal or between a terminal under a mobile router and a communication partner terminal without passing through a home agent.

It is a block diagram which shows the system configuration | structure of Embodiment 1 of this invention. It is a figure which shows the header structure of the packet between the mobile terminal used in Embodiment 1 etc. and a communicating party terminal. FIG. 3 is a sequence diagram of control signals between components in the first embodiment. FIG. 10 is another sequence diagram of control signals between the components of the first embodiment. It is a block diagram which shows the system configuration | structure of Embodiment 2 of this invention. It is a figure which shows the header structure of the packet used by Embodiment 2 etc. FIG. 10 is a sequence diagram of control signals between components in the second embodiment. FIG. 10 is another sequence diagram of control signals between the components of the second embodiment. It is a figure which shows the other header structure of the packet used by Embodiment 2 etc. It is a block diagram which shows the system configuration | structure of Embodiment 3 of this invention. FIG. 11 is a sequence diagram of control signals between components in the third embodiment. FIG. 10 is another sequence diagram of control signals between the components of the third embodiment. It is a block diagram which shows the system configuration | structure of Embodiment 4 of this invention. FIG. 10 is a sequence diagram of control signals between components in the fourth embodiment. FIG. 20 is another sequence diagram of control signals between the components of the fourth embodiment. It is a block diagram which shows the system configuration | structure of Embodiment 5 of this invention. FIG. 10 is a sequence diagram of control signals between components in the fifth embodiment. It is a block diagram which shows the system configuration | structure of Embodiment 6 of this invention. FIG. 20 is a sequence diagram of control signals between components in the sixth embodiment. It is a block diagram which shows the system configuration | structure of Embodiment 7 of this invention. FIG. 20 is a sequence diagram of control signals between components in the seventh embodiment. It is a block diagram which shows the system configuration | structure of Embodiment 8 of this invention. FIG. 20 is a sequence diagram of control signals between components in the eighth embodiment. It is a sequence diagram of the control signal between each component of Embodiment 9 of this invention. FIG. 20 is a diagram showing a header configuration of a packet used in the ninth embodiment. It is a sequence diagram of the control signal between each component of Embodiment 10 of this invention. FIG. 38 is a diagram illustrating a header configuration of a packet used in the tenth embodiment. It is a block diagram which shows the system configuration | structure of Embodiment 11 of this invention. FIG. 38 is a sequence diagram of control signals between components in the eleventh embodiment. It is a block diagram which shows the system configuration | structure of Embodiment 12 of this invention. FIG. 38 is a sequence diagram of control signals between components in the twelfth embodiment. It is a block diagram which shows the system configuration | structure of Embodiment 13 of this invention. FIG. 38 is a sequence diagram of control signals between components in the thirteenth embodiment.

Explanation of symbols

10, 11 Proxy routers AP1, AP2, AP3, AP4 Wireless base stations AP3-1, AP3-2, AP4-1, AP4-2 Wireless base stations AR, AR1, AR2 Access router CN, CN1, CN2 Remote node HA Home Agent MN Mobile terminal MR Mobile router
Node, Node1, Node2 terminal

Claims (20)

In a wireless communication system that performs communication between a mobile terminal and a communication partner terminal via an access router,
The mobile terminal
Before moving, a pre-location registration message including a care-of address used at the destination and the home address of the mobile terminal is transmitted to the communication partner terminal via the currently connected access router. Create and send a packet to the correspondent terminal using the care-of address sent in the registration message,
The communication partner terminal
When the pre-location registration message is received, a correspondence relationship between the care-of address and the home address after movement of the mobile terminal is created and stored based on the pre-location registration message, and when the movement of the mobile terminal is detected, the stored Update the correspondence between the current care-of address and the home address using the correspondence, create and send a packet to the mobile terminal using the updated correspondence ,
The access router shall include the information for creating the care-of address of the current mobile terminal and the information for creating the care-of address of the mobile terminal to be used at the next destination in the message periodically sent to the mobile terminal. radio communications system that characterized. The wireless communication system according to claim 1, wherein the communication partner terminal detects movement of the mobile terminal based on reception of a packet having a source address that matches the care-of address included in the pre-location registration message. . After moving, the mobile terminal sends a movement completion notification to the correspondent terminal,
The remote terminal is a wireless communication system according to claim 1, characterized in that for detecting the movement of the mobile terminal based on the reception of movement completion notification from the mobile terminal. In a wireless communication system that performs communication between a mobile terminal and a communication partner terminal via an access router,
The mobile terminal
Before moving, a pre-location registration message including a care-of address used at the destination and the home address of the mobile terminal is transmitted to the communication partner terminal via the currently connected access router. Create and send a packet to the correspondent terminal using the care-of address sent in the registration message,
The communication partner terminal
When the pre-location registration message is received, a correspondence relationship between the care-of address and the home address after movement of the mobile terminal is created and stored based on the pre-location registration message, and when the movement of the mobile terminal is detected, the stored Update the correspondence between the current care-of address and the home address using the correspondence, create and send a packet to the mobile terminal using the updated correspondence,
The access router periodically sends a message that is sent to the mobile terminal, including the address of the communication partner terminal to be connected at the next destination,
The mobile terminal acquires the address of the communication partner terminal to be connected next by the message from the access router, and moves to the communication partner terminal to be connected next through the currently connected access router before moving. radio communications system that and transmits the pre-location registration message including the home address of the care-of address with the mobile terminal of the mobile terminal used in the previous. In a wireless communication system that performs communication between a mobile terminal and a communication partner terminal accommodated in a proxy router via an access router,
The mobile terminal
Before moving, a pre-location registration message including a care-of address to be used at the destination and the home address of the mobile terminal is transmitted to the proxy router via the currently connected access router. Create and send a packet to the correspondent terminal using the care-of address sent in the message,
The proxy router
When the pre-location registration message is received, a correspondence relationship between the care-of address and the home address after movement of the mobile terminal is created and stored based on the pre-location registration message, and when the movement of the mobile terminal is detected, the stored Update the correspondence between the current care-of address and the home address using the correspondence, transfer the packet from the communication partner terminal to the mobile terminal using the updated correspondence ,
The access router shall include the information for creating the care-of address of the current mobile terminal and the information for creating the care-of address of the mobile terminal to be used at the next destination in the message periodically sent to the mobile terminal. radio communications system that characterized. The wireless communication system according to claim 5, wherein the proxy router detects movement of the mobile terminal based on reception of a packet having a source address that matches a care-of address included in the pre-location registration message. The mobile terminal sends a movement completion notification to the proxy router after moving,
The wireless communication system according to claim 5 , wherein the proxy router detects movement of the mobile terminal based on reception of a movement completion notification from the mobile terminal. In a wireless communication system that performs communication between a mobile terminal and a communication partner terminal accommodated in a proxy router via an access router,
The mobile terminal
Before moving, a pre-location registration message including a care-of address to be used at the destination and the home address of the mobile terminal is transmitted to the proxy router via the currently connected access router. Create and send a packet to the correspondent terminal using the care-of address sent in the message,
The proxy router
When the pre-location registration message is received, a correspondence relationship between the care-of address and the home address after movement of the mobile terminal is created and stored based on the pre-location registration message, and when the movement of the mobile terminal is detected, the stored Update the correspondence between the current care-of address and the home address using the correspondence, transfer the packet from the communication partner terminal to the mobile terminal using the updated correspondence,
The access router periodically includes the address of the communication partner terminal to be connected at the next movement destination and the address of the proxy router that accommodates the communication partner terminal to be connected at the next movement destination in the message periodically transmitted to the mobile terminal. Send
The mobile terminal obtains the address of the communication partner terminal to be connected next by the message from the access router and the address of the proxy router that accommodates the communication partner terminal to be connected at the next movement destination, and before moving, Send a pre-location registration message including the care-of address of the mobile terminal used at the destination and the home address of the mobile terminal to the proxy router that accommodates the next communication partner terminal via the currently connected access router. radio communications system that characterized. The access router stores the correspondence between the virtual address and the real address as the address of the communication partner terminal, notifies the subordinate mobile terminal of the virtual address as the address of the communication partner terminal,
The mobile terminal communicates with the communication partner terminal using the notified virtual address as the destination address,
The wireless communication system according to any one of claims 1 to 8, wherein the access router performs conversion between a virtual address and a real address for a packet transmitted and received between the mobile terminal and the communication partner terminal. In a wireless communication system in which a terminal accommodated in a mobile router and a communication partner terminal communicate via an access router,
Mobile router
Before moving, a pre-position registration message including a care-of address used at the moving destination and the home address of the mobile router is transmitted to the communication partner terminal via the currently connected access router. Transfer the packet from the terminal to the communication partner terminal using the care-of address sent in the registration message,
The communication partner terminal
When the pre-location registration message is received, a correspondence relationship between the care-of address after the movement of the mobile router and the home address is created and stored based on the pre-location registration message, and when the movement of the mobile router is detected, the stored Update the correspondence between the current care-of address and home address using the correspondence, create and send a packet to the terminal using the updated correspondence ,
The access router shall include the information for creating the care-of address of the current mobile router and the information for creating the care-of address of the mobile router to be used at the next destination in the message periodically sent to the mobile router. radio communications system that characterized. 11. The wireless communication system according to claim 10, wherein the communication partner terminal detects movement of the mobile router based on reception of a packet having a transmission source address that matches the care-of address included in the pre-location registration message. . The mobile router sends a movement completion notification to the correspondent terminal after movement,
The wireless communication system according to claim 10 , wherein the communication partner terminal detects movement of the mobile router based on reception of a movement completion notification from the mobile router. In a wireless communication system in which a terminal accommodated in a mobile router and a communication partner terminal communicate via an access router,
Mobile router
Before moving, a pre-position registration message including a care-of address used at the moving destination and the home address of the mobile router is transmitted to the communication partner terminal via the currently connected access router. Transfer the packet from the terminal to the communication partner terminal using the care-of address sent in the registration message,
The communication partner terminal
When the pre-location registration message is received, a correspondence relationship between the care-of address after the movement of the mobile router and the home address is created and stored based on the pre-location registration message, and when the movement of the mobile router is detected, the stored Update the correspondence between the current care-of address and home address using the correspondence, create and send a packet to the terminal using the updated correspondence,
The access router periodically sends the message sent to the mobile router including the address of the communication partner terminal to be connected at the next destination,
The mobile router acquires the address of the communication partner terminal to be connected next by the message from the access router, and moves to the communication partner terminal to be connected next through the currently connected access router before moving. A pre-location registration message including the care-of address of the mobile router used earlier and the home address of the mobile router is sent, and the communication partner terminal to be connected at the next destination received from the access router is sent to the subordinate terminal. radio communications system that and transmits a message including the address. In a wireless communication system that performs communication between a terminal accommodated in a mobile router and a communication counterpart terminal accommodated in a proxy router via an access router,
Mobile router
Before moving, a pre-location registration message including a care-of address used at the moving destination and the home address of the mobile router is transmitted to the proxy router via the currently connected access router. Forward the packet from the terminal to the proxy router using the care-of address sent in the message,
The proxy router
When the pre-location registration message is received, a correspondence relationship between the care-of address after the movement of the mobile router and the home address is created and stored based on the pre-location registration message, and when the movement of the mobile router is detected, the stored Update the correspondence between the current care-of address and the home address using the correspondence, transfer the packet from the communication partner terminal to the terminal using the updated correspondence ,
The access router shall include the information for creating the care-of address of the current mobile router and the information for creating the care-of address of the mobile router to be used at the next destination in the message periodically sent to the mobile router. radio communications system that characterized. The wireless communication system according to claim 14 , wherein the proxy router detects movement of the mobile router based on reception of a packet having a source address that matches a care-of address included in the pre-location registration message. The mobile router sends a move completion notification to the proxy router after moving,
The wireless communication system according to claim 14 , wherein the proxy router detects movement of the mobile router based on reception of a movement completion notification from the mobile router . In a wireless communication system that performs communication between a terminal accommodated in a mobile router and a communication counterpart terminal accommodated in a proxy router via an access router,
Mobile router
Before moving, a pre-location registration message including a care-of address used at the moving destination and the home address of the mobile router is transmitted to the proxy router via the currently connected access router. Forward the packet from the terminal to the proxy router using the care-of address sent in the message,
The proxy router
When the pre-location registration message is received, a correspondence relationship between the care-of address after the movement of the mobile router and the home address is created and stored based on the pre-location registration message, and when the movement of the mobile router is detected, the stored Update the correspondence between the current care-of address and the home address using the correspondence, transfer the packet from the communication partner terminal to the terminal using the updated correspondence,
The access router periodically includes the address of the correspondent terminal to be connected at the next destination and the address of the proxy router that accommodates the correspondent terminal to be connected at the next destination in the message periodically transmitted to the mobile router. Send
The mobile router obtains the address of the communication partner terminal to be connected next by the message from the access router and the address of the proxy router that accommodates the communication partner terminal to be connected at the next movement destination. A pre-location registration message including the care-of address of the mobile router used at the destination and the home address of the mobile router is sent to the proxy router that accommodates the next communication partner terminal via the currently connected access router. A wireless communication system, wherein a message including an address of a communication partner terminal to be connected at a next destination received from an access router is transmitted to a subordinate terminal. The mobile router stores the correspondence between the virtual address and the real address as the address of the communication partner terminal, notifies the subordinate terminal of the virtual address as the address of the communication partner terminal,
The terminal communicates with the communication partner terminal using the notified virtual address as the destination address,
Mobile router for packets that are exchanged between the terminal and the communication partner terminal to be accommodated in the mobile router, to any one of claims 10 to 17, characterized in that for converting between virtual and real addresses The wireless communication system described. A plurality of first radio base stations arranged so that the first radio area can be obtained continuously, and a second radio area overlapping the first radio area are arranged intermittently. A plurality of second radio base stations and a plurality of access routers accommodating the first and second radio base stations, and a terminal accommodated in a mobile router and a communication counterpart terminal are configured to transmit the second radio In a wireless communication system that performs communication via a base station and an access router,
The access router receives the information for creating the care-of address of the current mobile router and the information for creating the care-of address of the mobile router used in the second wireless area of the next destination. Periodically transmitted to the mobile router via one radio base station or second radio base station,
Mobile router
Based on the information received from the access router, before moving to the next second wireless area, the destination terminal is notified to the communication partner terminal via the currently connected first wireless base station and access router. The care-of address transmitted in the pre-position registration message after transmitting the pre-position registration message including the care-of address used in the wireless area 2 and the home address of the mobile router and moving to the second wireless area of the movement destination The packet from the terminal is transferred to the communication partner terminal using
The communication partner terminal
When the pre-location registration message is received, a correspondence relationship between the care-of address after the movement of the mobile router and the home address is created and stored based on the pre-location registration message, and when the movement of the mobile router is detected, the stored Update the correspondence between the current care-of address and home address using the correspondence, create and send a packet to the terminal using the updated correspondence ,
The access router includes information for creating a care-of address of the current mobile router, information for creating a care-of address of the mobile router used in the second wireless area of the next movement destination, and information of the next movement destination. The address of the communication partner terminal to be connected in the two wireless areas is periodically transmitted to the mobile router via the currently connected first wireless base station or the second wireless base station,
Mobile router
Based on the information received from the access router, before moving to the next second radio area, the second radio at the next destination via the first radio base station and the access router that are currently connected. A pre-location registration message including the care-of address used in the second wireless area of the moving destination and the home address of the mobile router is transmitted to the communication partner terminal to be connected in the area, and the access router receives the information from the access router. A message including an address of a communication partner terminal to be connected at the next destination to be received is transmitted, and after the movement, a packet from the terminal is transmitted to the communication partner terminal by using the care-of address transmitted in the prior location registration message. Forward,
The communication partner terminal to be connected in the second wireless area of the next destination is
When the pre-location registration message is received, a correspondence relationship between the care-of address after the movement of the mobile router and the home address is created and stored based on the pre-location registration message, and when the movement of the mobile router is detected, the stored using the corresponding relationship updating the correspondence between the current care-of address and the home address, radio communications systems that characterized in that creates and sends a packet to the terminal by using the correspondence relationship that the update. The radio communication system according to claim 19 , wherein the second radio base stations are arranged so that a second radio area can be obtained locally and continuously.

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