JP3645510B2 - Radio base station, radio terminal and communication control method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a wireless terminal that performs communication while moving through a network using a wireless link capable of bidirectional communication and a plurality of wireless links capable of communication in only one direction in an IP network. The present invention relates to a radio base station of a one-way radio link that establishes a radio link and relays data to a radio terminal, and a communication control method.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as a technology for guaranteeing the mobility of communication for a terminal that moves across a network on an IP (Internet Protocol) network, in the Internet Engineering Task Force (IETF), Mobile-IP (RFC 2002, “IP Mobility Support”). ) Has been specified.
[0003]
Hereinafter, Mobile-IP will be described.
[0004]
FIG. 8 shows a typical network configuration in Mobile-IP. A mobile terminal (MN: Mobile Node) 2200 is a terminal that moves through the network, and a communication counterpart terminal (CN: Correspondent Node) 2800 is a terminal that communicates with the mobile terminal 2200. The home network 2010 is a network determined by the mobile terminal 2200 as a home, and includes a packet relay device 2400 called a home agent (HA) that supports the movement of the mobile terminal 2200. The foreign network 2020 is a destination network of the mobile terminal 2200, and there is a packet relay apparatus 2300 called a foreign agent (FA) that supports communication of the mobile terminal 2200 in the foreign network 2020. However, Mobile-IP also assumes a form in which the foreign agent 2300 does not exist. In this case, the mobile terminal confidence needs to include a part of the function of the foreign agent. In the figure, reference numeral 2901 denotes a backbone network (IP network).
[0005]
Normally, in an IP network, an IP address that is a node identifier is also a location identifier. In the above example, the home address (Home address) given to the mobile terminal 2200 in the home network 2010 is a node identifier and also a location identifier. Therefore, when transmitting a packet to the mobile terminal 2200, the communication partner terminal 2800 transmits the packet on the assumption that the mobile terminal 2200 is at the home address.
[0006]
In Mobile-IP, in order to deliver a packet to a mobile terminal 2200 that has moved to a different network, a second address indicating its physical position, that is, a care-off address, is defined. . Here, the care-of address corresponds to a physical location of a transfer destination that transfers a packet that the mobile terminal 2200 should originally receive in the home network 2010 by a packet delivery method (tunneling) defined in Mobile-IP. Address.
[0007]
In order to correctly deliver a packet to this physical current position (care-of-address), the home agent 2400 holds information on the current position of the mobile terminal 2200, and the communication partner terminal 2800 transmits to the home address of the mobile terminal 2200. The received IP packet is received by proxy, and it is encapsulated and transferred to the care-of address of the foreign network 2020 where the mobile terminal 2200 is currently located.
[0008]
Here, the care-of address of the mobile terminal 2200 that communicates with the foreign network 2020 via the foreign agent 2300 is the address of the foreign agent 2300.
[0009]
The foreign agent 2300 that has received the forwarded packet inserts it into an appropriate link frame and forwards the packet to the mobile terminal 2200. Here, the destination address of the packet transferred to mobile terminal 2200 is the home address of mobile terminal 2200.
[0010]
As described above, when the mobile terminal 2200 communicates with the communication partner terminal 2800 in the foreign network 2020, the mobile terminal 2200 always receives packets on the home network 2010 by receiving support from the home agent 2400 and the foreign agent 2300. Can behave. Conversely, transmission of a packet from the mobile terminal 2200 to the communication partner terminal 2800 is normally transmitted directly without going through the home agent 2400. At this time, the source address of the packet is the home address of the mobile terminal 2200.
[0011]
Further, when the mobile terminal 2200 moves to the foreign network 2020, location registration processing is required for both to obtain support from the home agent 2400 and the foreign agent 2300.
[0012]
FIG. 9 shows a movement detection and registration processing sequence when the mobile terminal 2200 moves to the foreign network 0220.
[0013]
When the mobile terminal 2011 is located on the home network 2010, it directly communicates with the communication partner terminal 2800 (S4050).
[0014]
Then, it is assumed that the mobile terminal 2011 has moved to the foreign network 0220 (S4001).
[0015]
Here, the home agent 2400 and the foreign agent 2300 periodically send a control message called an agent advertisement (agent advertisement message) in order to inform the mobile terminal 2200 of the current location and convey the intention of providing the service. Broadcast (or multicast) (S4002).
[0016]
The mobile terminal 2200 that has moved to the foreign network 2020 detects an IP network-like movement by receiving the AgentAdvertisement (S4003), and transmits a movement registration request to use the Mobile-IP service to the foreign agent 2300 ( S4004). The foreign agent 2300 that has received the movement registration request performs necessary relay processing (S4005), and then transfers the movement registration request to the home agent 2400 (S4006).
[0017]
The home agent 2400 that has received the movement registration request performs movement registration processing for the mobile terminal 2200 (S4007), and transmits a movement registration response to the foreign agent 2300 (S4008). The foreign agent 2300 that has received the mobile registration response performs necessary relay processing (S4009), and transfers the mobile registration response to the mobile terminal 2200 (S4010).
[0018]
Upon receiving the registration response message, the mobile terminal 2200 performs routing setting (S4011).
[0019]
Thereafter, the communication between the mobile terminal 2200 and the communication partner terminal 2800 is continued through the home agent 2400 and the foreign agent 2300 (S4051 to S4054).
[0020]
In addition, even when moving from the foreign network 2020 to a different foreign network 2021, it is detected that the movement to the new foreign network 2021 is triggered by reception of the Agent Advertisement, and a new location registration process is performed via the foreign agent 2310. Start.
[0021]
On the other hand, IGMP (RFC 1112, Internet Group Management Protocol) is specified in IETF as a protocol for realizing multicast communication across networks. IGMP is a protocol for detecting whether there is a node that desires to participate in a multicast group in any network to which a router is directly connected.
[0022]
A multicast group is a set of a plurality of terminals that perform multicast communication using a certain multicast address.
[0023]
FIG. 10 shows a typical network configuration when performing multicast communication using IGMP. The mobile terminal 3200 is a terminal that moves on the network, and performs multicast communication with the communication partner terminal 3800 and the communication partner terminal 3810 (and other terminals (not shown)). Multicast routers (MRs) 3400, 3410, 3420, and 3430 are multicast routing routers. When IGMP detects that a terminal that joins a multicast group exists in one of networks directly connected to the multicast router, the multicast router (MR) 3400, 3410, 3420, 3430 Routing setting is performed so that multicast communication can be performed between a plurality of terminals to which the terminals belong, and packets are transferred.
[0024]
FIG. 11 shows a procedure for continuing multicast communication in the destination network when the mobile terminal 3200 that has started multicast communication moves in the network during communication.
[0025]
Here, it is assumed that communication using a multicast address is already performed between the terminal 3800 and the terminal 3810 (S4000).
[0026]
The mobile terminal 3200 that has activated the multicast application in the network 3010 (S4001) transmits an IGMP Report (IGMP report message) in order to inform the multicast router 3400 of the multicast group desired to join (S4002). The multicast router 3400 that has received the IGMP Report (S4003) performs routing setting for the multicast group that the mobile terminal 3200 desires to join (S4004). Thereafter, multicast communication is performed among the mobile terminal 3200, the communication partner terminal 3800, and the communication partner terminal 3810 belonging to the same multicast group (S4050).
[0027]
In addition, the multicast router 3400 periodically transmits an IGMP Query (IGMP query message) to check whether there is a node that joins the multicast group in the network to which the self-confidence is connected (S4005), and the mobile terminal 3200 responds with IGMP Report (S4006). The mobile terminal 3200 normally does not transmit the IGMP Report without receiving the IGMP Query except when starting the multicast application for the first time.
[0028]
Next, when the mobile terminal 3200 moves to the network 3011 (S4007), the multicast router 3410 does not perform the routing setting for the multicast group to which the mobile terminal 3200 joins, so that multicast communication with the communication partner terminals 3800 and 3810 is performed. Disconnected. The multicast router 3410 periodically transmits an IGMP Query in the same manner as other multicast routers (S4008). Receiving this, the mobile terminal 3200 returns information on the multicast group to which the user joins as IGMP Report (S4009). The multicast router 3410 (S4010) that has received the IGMP Report performs routing setting for the multicast group to which the mobile terminal 3200 joins (S4011). Thereafter, multicast communication is resumed between the communication partner terminal 3800 and the communication partner terminal 3810 in the same manner as when connected to the network 3010.
[0029]
Now, consider applying a network to which Mobile-IP or IGMP is applied to a wireless system. In general, when building an information download system (whether wired or wireless), the amount of information in the direction (downlink) from the network side (server device) to the user side (terminal) is smaller than the uplink in the reverse direction. There is a feature that is large. In addition, in order to realize a new high-speed downlink network at a low cost by using an existing narrowband wide area network such as PHS and PDC as it is, it is received together with a bidirectional wireless interface by the existing narrowband wide area network. A configuration with a dedicated new high-speed downlink radio interface is conceivable. This asymmetric scheme combining the existing wide area network for the uplink and the new high speed downlink network for the downlink is called a hybrid scheme.
[0030]
Here, a hybrid wireless mobile terminal having a first wireless interface for high-speed downlink that can be used only for reception as a mobile terminal and a second wireless interface for an existing wide area network that can be used for transmission and reception is considered.
[0031]
Even if the mobile terminal has moved to a wireless area where the first wireless interface can be used or handed off between the first wireless base stations (that is, connected to the foreign network), between the foreign network and the mobile terminal, It is assumed that only one-way (foreign network → mobile terminal direction) packet transmission is possible. In addition, the radio area of the first radio base station is included in the radio area of the second radio base station (see FIG. 7). That is, it is assumed that a mobile terminal that can communicate with the first radio base station (only reception) can communicate with the second radio base station at the same time.
[0032]
When the mobile terminal moves to the service area of the first radio base station, the radio link establishment process with the first radio base station and the upper layer processes such as Mobile-IP and IGMP are performed independently. Therefore, the movement registration process to the foreign agent in the foreign network cannot be started until the Agent Advertisement periodically transmitted by the foreign agent is received. Similarly, the multicast group joining process to the multicast router cannot be started until receiving the IGMP Query periodically transmitted by the multicast router. Further, even if the mobile terminal is configured to detect establishment of a radio link and start higher layer processing, the first radio interface can only be used for reception. It is not possible to directly send IP Agent Solitization (Agent Solicitation Message) or IGMP Report from the first wireless interface. On the other hand, since a foreign agent or a multicast router normally sends an Agent Advertisement or IGMP Query asynchronously with the establishment of a radio link with the first radio base station, the foreign agent or multicast router It is also impossible to trigger the start of higher layer processing.
[0033]
[Problems to be solved by the invention]
As described above, a hybrid type wireless mobile terminal having a wireless interface capable of bidirectional communication and a wireless interface capable of communication in only one direction communicates using a wireless link in both the upper and lower directions depending on the position form. There are two types of communication modes: a case where communication is performed, and a case where communication is performed using an uplink bidirectional link / downlink unidirectional link. Here, establishment of a radio link with the first radio base station when moving to a service area where a one-way radio link can be used, movement registration processing at the IP layer by Mobile-IP, and multicast group by IGMP Conventionally, upper layer processing such as subscription processing is independently performed. Therefore, in the destination network, the Mobile-IP move registration process and the multicast group join process are started until the Agent Advertisement periodically sent by the foreign agent or the IGMP Query periodically sent by the multicast router is received. Can not. As a result, when the connected network changes, in order to continue the unicast or multicast communication performed in the previously connected network, it is necessary to wait for the reception of the control message, which is originally Mobile-IP. Since IGMP is not a protocol designed in consideration of radio, it takes time until unicast or multicast communication can be resumed in an environment where the transmission cycle of control messages is set to be long. In addition, the period can be adjusted, and the bandwidth of the communication line is wasted even if the transmission period of control messages such as Agent Advertisement and IGMP Query is shortened.
[0034]
The present invention has been made in view of the above circumstances, and a wireless terminal equipped with a wireless interface that can be used only for reception without shortening the transmission cycle of the control message is faster than the conventional processing related to the control message. It is an object of the present invention to provide a radio base station, a radio terminal, and a communication control method that can start the communication.
[0035]
[Means for Solving the Problems]
The present invention transmits data to be received via a first wireless interface to a wireless terminal having a first wireless interface usable only for reception and a second wireless interface usable for transmission / reception. A wireless base station for establishing a wireless link related to the first wireless interface with the wireless terminal, and the wireless link between the wireless terminal and the wireless terminal by the setting means. It is characterized by comprising a transmission means for transmitting a predetermined control message related to a protocol higher than the wireless link when established.
[0036]
Preferably, the wireless communication system further includes caching means for receiving and caching the predetermined control message transmitted by a predetermined node belonging to the same network as the network to which the base station belongs, every predetermined period, When the link is established, the predetermined control message cached by the caching unit may be transmitted to the wireless terminal on behalf of the predetermined node.
[0037]
Preferably, the wireless terminal further comprises creation means for creating the predetermined control message to be transmitted by the wireless terminal to a predetermined node belonging to the same network as the network to which the base station belongs. The predetermined control message created by the creating unit may be transmitted to the predetermined node on behalf of the wireless terminal when the communication is established. Preferably, the transmission means includes control information including a request to transmit the predetermined control message from the wireless mobile terminal to the predetermined node when establishing a wireless link with the wireless terminal. When received, when the wireless link is established, the predetermined control message created by the creating means is transmitted to the predetermined node on behalf of the wireless terminal. Also good.
[0038]
The present invention also provides data to be received via a first wireless interface to a wireless terminal having a first wireless interface that can be used only for reception and a second wireless interface that can be used for transmission and reception. In a communication control method in a radio base station for transmitting a predetermined node according to a protocol higher than a radio link, which is transmitted every predetermined period by a predetermined node belonging to the same network as the network to which the base station belongs Receive and cache a control message, establish a wireless link related to the first wireless interface with the wireless terminal, and when the wireless link is established with the wireless terminal, The cached predetermined control message is transmitted to the wireless terminal on behalf of the predetermined node And wherein the door.
[0039]
The present invention also provides data to be received via a first wireless interface to a wireless terminal having a first wireless interface that can be used only for reception and a second wireless interface that can be used for transmission and reception. In the communication control method in the radio base station for transmitting the radio link, the radio link related to the first radio interface is established with the radio terminal, and the radio link is established with the radio terminal. With this as an opportunity, the wireless terminal should transmit to a predetermined node belonging to the same network as the network to which the base station belongs, and create the predetermined control message related to a higher layer protocol than the wireless link, The created predetermined control message is transmitted to the predetermined node on behalf of the wireless terminal.
[0040]
Further, according to the present invention, in a wireless terminal having a first wireless interface that can be used only for reception and a second wireless interface that can be used for transmission and reception, the wireless terminal should receive via the first wireless interface of the terminal itself. Setting means for establishing a radio link related to the first radio interface with a radio base station for transmitting data, and the radio base station at the time of establishing the radio link with the radio base station In response, the terminal transmits a predetermined control message related to a protocol higher than the radio link to be transmitted to a predetermined node belonging to the same network as the network to which the radio base station belongs. And transmitting means for transmitting control information including a request for transmission to the predetermined node.
[0041]
The present invention relating to a radio base station is also established as an invention relating to a communication control method in a radio base station or a communication system, and the present invention relating to a radio terminal is also valid as an invention relating to a communication control method in a radio terminal or a communication system. However, the present invention relating to the method is also established as an invention relating to the apparatus.
Further, the present invention relating to an apparatus or a method has a function for causing a computer to execute a procedure corresponding to the invention (or for causing a computer to function as a means corresponding to the invention, or for a computer to have a function corresponding to the invention. It is also established as a program (for realizing) and also as a computer-readable recording medium on which the program is recorded.
[0042]
According to the present invention, a wireless mobile terminal compatible with a hybrid system having a wireless interface that can be used only for reception and a wireless interface that can be used for transmission and reception can transmit and receive uplink communication from a communication state that uses only a wireless link that can transmit and receive. Switching to a possible wireless link / radio link dedicated to downlink reception, and in synchronization with wireless handoff between base stations of the radio link dedicated to reception, for example, Mobile-IP location registration processing or multicast group subscription processing, etc. Therefore, unicast or multicast communication can be continued smoothly at the time of switching the communication state or handoff between base stations.
[0043]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the invention will be described with reference to the drawings.
[0044]
(First embodiment)
In the present embodiment, in the unicast communication of a hybrid wireless mobile terminal, one of the wireless links used for downlink communication to the wireless mobile terminal can be used only in one direction, and the downlink wireless link is used. Can be applied when a wireless link establishment process is required between a wireless mobile terminal and a wireless base station. However, the wireless link is not necessarily limited to one direction, but works effectively in a wireless link that can be used only in one direction. For example, in the case of IEEE802.11, HiperLAN2, or MMAC, a terminal can perform communication using a wireless link by executing a wireless link establishment process with the wireless base station. The present invention is applicable to general cases including these.
[0045]
FIG. 1 shows an example of a network configuration including a radio base station apparatus, an agent apparatus, and a radio mobile terminal apparatus according to an embodiment of the present invention.
[0046]
As shown in FIG. 1, this network includes first radio base stations (AP) 100 and 110, radio terminals (wireless mobile terminals) (MN) 200, foreign agents (FA) 300 and 310, and home agents (HA) 400. , Access server (AS) 600, second radio base station (CS) 700, 701, communication counterpart terminal (CN) 800 of radio mobile terminal 200, backbone network 901, mobile communication network 902, local area networks 903, 904 905, the first radio base station service areas 1001 and 1002, and the second radio base station service area 1101. Although two foreign networks are shown in FIG. 1, the number of foreign networks is not particularly limited to this.
[0047]
The wireless mobile terminal 200 is a terminal that moves on a network. The communication partner terminal 800 is an arbitrary terminal that communicates with the wireless mobile terminal 200 in an IP manner. In FIG. 1, only one wireless mobile terminal 200 is shown, but a plurality of wireless mobile terminals 200 may exist.
[0048]
The radio mobile terminal 200 includes a first radio interface 201 for communicating with the first radio base stations 100 and 110, and a first radio link for establishing a radio link with the first radio base stations 100 and 110. The wireless link establishment function 202, the second wireless interface 203 for communicating with the second wireless base stations 700 and 701, and the access server 600 by establishing a wireless link with the second wireless base stations 700 and 701 A second wireless link establishment function 204 for enabling communication of the mobile node, and a mobile node control function 205 for controlling Mobile-IP, PPP (Point to Point Protocol, RFC1661), and the like.
[0049]
Here, the first wireless interface 201 can be considered to have only a reception function or a transmission / reception function.
This embodiment assumes a case where the wireless mobile terminal 200 cannot transmit a message to the first wireless base stations 100 and 110 by the first wireless interface 201. (1) The first wireless base station 100 , 110 can only transmit, and the first radio interface 201 of the radio mobile terminal 200 can only receive. (2) The first radio base stations 100 and 110 can transmit and receive, and the first radio base station The wireless interface 201 can receive only (in this case, a terminal having a bidirectional wireless communication function can exist between the first wireless base station 100 and 110 such as the wireless mobile terminal 210) (3 The first radio base stations 100 and 110 can only transmit, and the first radio interface 201 of the radio mobile terminal 200 can be used for both transmission and reception.
This is the same for the second embodiment.
[0050]
It is assumed that the second wireless interface 202 has a transmission / reception function.
[0051]
Further, in FIG. 1, the service area covered by the first radio base station and the service area covered by the second radio base station are individually shown. However, as shown in FIG. The radio areas 1001 and 1002 of the radio base station are included in the radio area 1101 of the second radio base station. That is, when the mobile radio terminal 200 is in a state where communication with the first radio base stations 100 and 110 is possible, it is assumed that the radio mobile terminal 200 is also in communication with the second radio base stations 700 and 701 at the same time.
For example, the radio area of one second radio base station includes only the radio area of the first radio base station belonging to the same foreign network, and the first radio base station belonging to a different foreign network There may be a case where multiple wireless areas coexist. In addition, for example, when the radio areas of a plurality of first radio base stations belonging to the same foreign network are covered by the radio area of one second radio base station, the radio areas of the plurality of second radio base stations It may be covered by the area.
These points are the same as in the second embodiment.
[0052]
Although FIG. 1 shows two first radio base stations and two second radio base stations, any number may exist. Further, the movement control of the terminal between the second radio base stations is performed in the second radio base stations 700 and 701 and the mobile communication network 902, and is transparent to the radio mobile terminal 200 and the access server 600. It is. That is, even if the second radio base station with which the mobile radio terminal 200 communicates changes, the communication between the radio mobile terminal and the access server is not affected.
[0053]
The first radio base station 100 is connected to the local area network 904 in the foreign network 20 by the first interface 101 and to the radio mobile terminal 200 through the radio by the second interface 104. In addition, a wireless link establishment function 102 for establishing a wireless link with the first wireless interface 201 of the wireless mobile terminal 200, and Mobile-IP Agent Advertisement periodically transmitted by a foreign agent are received and cached. In addition, when it is detected that a wireless link has been established with the wireless mobile terminal, the mobile-IP control function 103 for transmitting the cached Agent Advertiseme to the wireless mobile terminal 200 is provided. The first radio base station 100 performs service only in the service area 1001, and when the radio mobile terminal 200 moves to the service area 1002, the first radio base station 110 performs service.
[0054]
The first radio base station 110, the foreign network 21, and the service area 1002 are the same as the first radio base station 100, the foreign network 20, and the service area 1001.
[0055]
Note that the Mobile-IP control function (103, 113) of the first radio base station may be realized as a device different from the first radio base station.
[0056]
The foreign agent 300 is connected to the local area network 904 and functions as a Mobile-IP foreign agent. Similarly, the foreign agent 310 is connected to the local area network 905 and functions as a Mobile-IP foreign agent.
[0057]
The home agent 400 is connected to the local area network 903 and functions as a Mobile-IP home agent.
[0058]
Access server 600 functions as a dial-up access server that terminates PPP connection with wireless mobile terminal 200.
[0059]
Second radio base stations 700 and 701 connect radio mobile terminal 200 and access server 600 through mobile communication network 902. The second radio base station and the mobile communication network are, for example, those when PHS, PDC, and cdma-One are used for data communication, but are not necessarily limited to these.
[0060]
Moreover, although the home agent 400 and the access server 600 are shown as separate devices, they may be integrated devices. Similarly, the first radio base station 100 and the foreign agent 300 may be integrated devices. Similarly, the first radio base station 110 and the foreign agent 310 may also be integrated devices.
[0061]
Hereinafter, the sequence of the present embodiment will be described.
[0062]
FIG. 2 shows an example of a sequence when the mobile terminal 200 moves from the home network 10 to the foreign network 20.
[0063]
First, the mobile radio terminal 200 establishes a connection by PPP with the access server 600 via the second radio base station 700 and the mobile communication network 902 (S1101 to S1103 in FIG. 2). Various parameters relating to PPP are negotiated and authenticated between the mobile node control function 205 and the access server 600, but details of the procedure are omitted here. The PPP negotiation (S1102) may include a plurality of message exchanges. When the PPP negotiation is completed, the wireless mobile terminal 200 is connected to the backbone network 901 in an IP manner and can communicate with an arbitrary device connected to the backbone network in an IP manner. At this time, the IP address assigned to the wireless mobile terminal 200 is set as the home address in Mobile-IP. The communication between the radio mobile terminal 200 and the communication partner terminal 800 at this stage is performed by the second radio base station both in the uplink (direction transmitted from the radio mobile terminal 200) and in the downlink (direction received by the radio mobile terminal 200). 700 and the mobile communication network 902 (S1150).
[0064]
Next, when the mobile radio terminal 200 moves to the service area 1001 of the first radio base station 100, downlink unicast communication can be performed via the first radio base station 100. The uplink communication keeps the state via the second radio base station 700. In the present embodiment, Mobile-IP is used to realize this.
[0065]
Here, the foreign agent 300 periodically multicasts (or broadcasts) Agent Advertisement to the local area network 904 (S1104). The Agent Advertisement is periodically transmitted to the service area 1002 of the first radio base station via the first radio base station 100. Also, the first radio base station 100 caches the latest Agent Advertisement that is periodically transmitted by the Mobile-IP control function 103 (S1105). However, when the foreign agent 300 and the first radio base station are integrated devices, it is not always necessary to cache.
[0066]
The first radio base station 100 periodically transmits control information such as BCCH (Broadcast Control Channel) to notify the presence of the base station through the radio (S1106). Upon receiving this BCCH and detecting a base station (S1107), the radio link establishment function 202 of the radio mobile terminal 200 establishes a radio link with the radio link establishment function 102 of the first radio base station 100 ( S1108). In establishing a wireless link, a plurality of messages are exchanged for setting various parameters, authenticating, and the like, but a method and a procedure for transmitting and receiving those messages are omitted here.
[0067]
Here, when the first radio base station 100 detects that a radio link is established with the radio mobile terminal 200 (S1109), the cached Agent Advertisement is transmitted via radio (S1110). When the first radio base station 100 and the foreign agent 300 are an integrated device, it may be detected that a radio link has been established, and the foreign agent function of the device may transmit Agent Advertisement.
[0068]
When the mobile node control function 205 of the wireless mobile terminal 200 receives the Agent Advertisement and detects that it has moved to the foreign network 20 (S1111), it transmits a movement registration request message with the foreign agent 300 as the destination (S1112). The movement registration request message is received by the foreign agent 300 via the second radio base station 700, the mobile communication network 902, the access server 600, the local area network 903, the backbone network 901, and the local area network 904. However, the transmission route of the movement registration request is not limited to this.
[0069]
When the foreign agent 300 receives the movement registration request message transmitted from the wireless mobile terminal 300, the foreign agent 300 performs a relay process (S1113) and then forwards it to the home agent 400 (S1114).
[0070]
Upon receiving the movement registration request message, the home agent 400 performs movement registration processing in accordance with the Mobile-IP specification (S1115). If it is determined that the registration request message is valid, a mobile registration response message including a notification of successful registration is transmitted to the foreign agent 300 (S1116). Thereafter, when the home agent 400 receives a packet addressed to the home address of the wireless mobile terminal 300, it encapsulates it and forwards it to the foreign agent 300, that is, to the care-of address.
[0071]
Upon receiving the mobile registration response message, the foreign agent 300 performs necessary relay processing (S1117), and relays the mobile registration response to the wireless mobile terminal 200 (S1118).
[0072]
When the mobile node control function 205 of the wireless mobile terminal 200 knows that the registration request has been accepted by the mobile registration response message, the mobile node control function 205 receives a packet addressed to itself from the first wireless interface 201 and receives a packet other than that addressed to itself. Performs routing setting so as to transmit from the second wireless interface 203 (S1119).
[0073]
At this stage, communication in the direction from the wireless mobile terminal 200 to the communication counterpart terminal 800 (S1151) remains via the second radio base station 700, but communication in the direction from the communication counterpart terminal 800 to the radio mobile terminal 200 (S1152). ) Is changed to pass through the first radio base station 100. On the way, the IP packet is encapsulated (S1153) and transferred to the corresponding IP packet addressed to the care-of address in the home agent 400 (S1154), and the foreign agent 300 receiving it is decapsulated (S1155) and then taken out. The transmitted packet is transmitted to the wireless mobile terminal 200 (S1156).
[0074]
Next, when the wireless mobile terminal 200 moves from the service area 1001 of the first wireless base station 100 to the service area 1002 of another first wireless base station 110, unicast communication with the communication partner terminal 800 is performed. , Switching to via the first radio base station 110.
[0075]
FIG. 3 shows an example of a sequence when the mobile terminal 200 moves to the foreign network 21.
[0076]
Here, the foreign agent 310 periodically multicasts (or broadcasts) Agent Advertisement to the local area network 905 (S1204). The Agent Advertisement is periodically transmitted to the service area 1003 of the first radio base station via the first radio base station 110. Also, the first radio base station 110 caches the latest Agent Advertisement that is periodically transmitted by the Mobile-IP control function 113 (S1205). However, when the foreign agent 310 and the first radio base station are integrated devices, it is not always necessary to cache.
[0077]
Similar to the first radio base station 100, the first radio base station 110 periodically transmits a BCCH notifying the presence of the base station through the radio (S1206). Upon receiving this BCCH and detecting a new base station (S1209), the radio link establishment function 202 of the radio mobile terminal 200 establishes a radio link with the radio link establishment function 102 of the first radio base station 100. (S1208). In establishing a wireless link, a plurality of messages are exchanged for setting various parameters, authenticating, etc., but the method and procedure for transmitting and receiving those messages are omitted here.
[0078]
Here, when the first radio base station 110 detects that a radio link has been established with the radio mobile terminal 200 (S1209), the cached Agent Advertisement is transmitted via radio (S1210). When the first radio base station 110 and the foreign agent 310 are an integrated device, it may be detected that a radio link has been established, and the foreign agent function of the device may transmit Agent Advertisement.
[0079]
When the mobile node control function 205 of the wireless mobile terminal 200 receives the Agent Advertisement and detects that it has moved to the foreign network 21 (S1211), it transmits a movement registration request message with the foreign agent 310 as the destination (S1212). The movement registration request message is received by the foreign agent 310 via the second radio base station 700, the mobile communication network 902, the access server 600, the local area network 903, the backbone network 901, and the local area network 905. However, the transmission route of the movement registration request is not limited to this.
[0080]
When the foreign agent 310 receives the movement registration request message transmitted from the wireless mobile terminal 200, the foreign agent 310 performs a relay process (S1213) and then forwards it to the home agent 400 (S1214).
[0081]
Upon receiving the movement registration request message, the home agent 400 performs movement registration processing in accordance with the Mobile-IP specification (S1215). If it is determined that the registration request message is valid, a mobile registration response message including a notification of successful registration is transmitted to the foreign agent 310 (S1216). Thereafter, when the home agent 400 receives a packet addressed to the home address of the wireless mobile terminal 200, the home agent 400 encapsulates it and forwards it to the foreign agent 310, that is, the current care-of address.
[0082]
Upon receiving the mobile registration response message, the foreign agent 310 performs necessary relay processing (S1217), and relays the mobile registration response to the wireless mobile terminal 200 (S1218).
[0083]
When the mobile node control function 205 of the wireless mobile terminal 200 knows that the registration request has been accepted by the mobile registration response message, the mobile node control function 205 receives a packet addressed to itself from the first wireless interface 201 and receives a packet other than that addressed to itself. Performs routing setting so as to transmit from the second wireless interface 203 (S1219).
[0084]
At this stage, the communication from the wireless mobile terminal 200 toward the communication partner terminal 800 (S1251) remains via the second wireless base station 700, but the communication from the communication partner terminal 800 toward the wireless mobile terminal 200 (S1252). ) Is changed so as to pass through the first radio base station 110. On the way, the IP packet is encapsulated (S1253) and transferred (S1254) to the IP packet addressed to the corresponding care-of address in the home agent 400, and the foreign agent 310 receiving it is decapsulated (S1255) and taken out. The transmitted packet is transmitted to the wireless mobile terminal 200 (S1256).
[0085]
In the above, the radio base stations 100 and 110 use the cached Agent Advertisement as a trigger when the radio link is established with the radio mobile terminal 200 (instead of the foreign agents 300 and 310). The radio base stations 100 and 110 transmit Agent Solicitation (instead of the radio mobile terminal 200) triggered by the establishment of a radio link with the radio mobile terminal 200. A configuration in which transmission to the foreign agents 300 and 310 is also possible. In this case, for example, when establishing the radio link, the radio mobile terminal 200 requests the radio base stations 100 and 110 to request that the Agent Solicitation be transmitted to the foreign agents 300 and 310 on behalf of the radio base stations 100 and 110. When the radio base stations 100 and 110 have received the control information at the time of establishing the radio link, the agent solicitation is performed on behalf of the foreign agent 300, What is necessary is just to make it transmit to 310.
[0086]
Further, instead of the wireless base station, another node (server) belonging to the same network as the wireless base station detects that a wireless link is established between the wireless mobile terminal and the wireless base station, and A form in which a control message is transmitted is also possible.
[0087]
As described above, according to the present embodiment, a wireless mobile terminal supporting a hybrid system having a wireless interface usable only for reception and a wireless interface usable for transmission / reception uses only a wireless link capable of transmission / reception. The mobile-IP location registration processing is performed in synchronization with the wireless communication between the base station of the wireless link that can transmit / receive uplink and the wireless link dedicated to downlink reception, and between the base stations of the dedicated wireless link. Therefore, unicast communication can be continued smoothly at the time of switching the communication state or handing off between base stations.
[0088]
(Second Embodiment)
In this embodiment, in the multicast communication of a hybrid radio mobile terminal, one of the radio links used in the downlink direction of the radio mobile terminal can be used only in one direction, and in order to use the downlink radio link, The present invention can be applied when a wireless link establishment process is required between a terminal and a wireless base station. It is assumed that the wireless mobile terminal can receive multicast data only when moving to an area where a one-way wireless link can be used. Further, the radio link is not necessarily limited to one direction, but works effectively in a radio link that can be used only in one direction. For example, in the case of IEEE802.11, HiperLAN2, or MMAC, a terminal can perform communication using a wireless link by executing a wireless link establishment process with the wireless base station. The present invention is applicable to general cases including these.
[0089]
FIG. 4 shows an example of a network configuration including a radio base station apparatus and a radio mobile terminal apparatus according to an embodiment of the present invention.
[0090]
As shown in FIG. 4, this network includes first radio base stations (AP) 100 and 110, a radio terminal (wireless mobile terminal) (MN) 200, multicast routers (MR) 500 and 510, a router 520, an access server ( AS) 600, second radio base station (CS) 700, 701, multicast communication terminal (communication partner terminal) (CN) 800, backbone network 901, mobile communication network 902, local area networks 903, 904, 905, first Wireless base station service areas 1001 and 1002 and a second wireless base station service area 1101. Although two foreign networks are shown in FIG. 4, the number of foreign networks is not particularly limited to this.
[0091]
The multicast routers 500 and 510 are routers that perform multicast routing.
[0092]
The router 520 has both a multicast routing function and a unicast routing function.
[0093]
The wireless mobile terminal 200 is a terminal that moves on a network. The multicast communication terminal 800 is an arbitrary device that performs multicast communication. In FIG. 1, only one wireless mobile terminal 200 is shown, but a plurality of wireless mobile terminals 200 may exist.
[0094]
The radio mobile terminal 200 includes a first radio interface 201 for communicating with the first radio base stations 100 and 110, and a first radio link for establishing a radio link with the first radio base stations 100 and 110. The wireless link establishment function 202, the second wireless interface 203 for communicating with the second wireless base stations 700 and 701, and the access server 600 by establishing a wireless link with the second wireless base stations 700 and 701 A second wireless link establishment function 204 for enabling communication of the mobile node, and a mobile node control function 303 for controlling Mobile-IP, PPP (Point to Point Protocol, RFC1661), and the like.
[0095]
Here, the first wireless interface 201 can be considered to have only a reception function or a transmission / reception function.
As described in the first embodiment, there are various cases where the wireless mobile terminal 200 cannot transmit a message to the first wireless base station depending on the first wireless interface 201 (the wireless mobile terminal 210 is also the first case). This is the same as the embodiment of FIG.
[0096]
It is assumed that the second wireless interface 202 has a transmission / reception function.
[0097]
Further, as described in the first embodiment, the wireless area of the first wireless base station is included in the wireless area of the second wireless base station (see FIG. 7).
[0098]
Although FIG. 4 shows two first radio base stations and two second radio base stations, any number may exist. Further, the movement control of the terminal between the second radio base stations is performed in the second radio base stations 700 and 701 and the mobile communication network 902, and is transparent to the radio mobile terminal 200 and the access server 600. It is. That is, even if the second radio base station with which the mobile radio terminal 200 communicates changes, the communication between the radio mobile terminal and the access server is not affected.
[0099]
The first radio base station 100 is connected to the local area network 904 in the foreign network by the first interface 101 and to the radio mobile terminal 200 by the second interface 104. A wireless link establishment function 102 for establishing a wireless link with the first wireless interface 201 of the wireless mobile terminal 200; receiving an address of a multicast group to which the wireless mobile terminal 200 belongs at the time of establishing the wireless link; When it is detected that a wireless link has been established with the wireless mobile terminal, an IGMP Report is created based on the multicast address received from the wireless mobile terminal, and an IGMP Report is transmitted on behalf of the wireless mobile terminal It has an IGMP control function 105. The first radio base station 100 performs service only in the service area 1001 of the first radio base station.
[0100]
The first radio base station 110, the foreign network 21, and the service area 1002 are the same as the first radio base station 100, the foreign network 20, and the service area 1001.
[0101]
In addition, you may implement | achieve the IGMP control function (105,115) of a 1st radio base station as an apparatus different from the said 1st radio base station.
[0102]
The access server 600 functions as a dial-up access server that terminates the PPP connection from the wireless mobile terminal 200.
[0103]
Second radio base stations 700 and 701 connect radio mobile terminal 200 and access server 600 through mobile communication network 902. The second radio base station and the mobile communication network are, for example, those when PHS, PDC, and cdma-One are used for data communication, but are not necessarily limited to these.
[0104]
Hereinafter, the processing sequence of this embodiment will be described.
[0105]
FIG. 5 shows an example of a sequence when the mobile terminal 200 moves from the home network 10 to the foreign network 20.
[0106]
First, the wireless mobile terminal 200 establishes an IP connection by PPP with the access server 600 via the second wireless base station 700 and the mobile communication network 902 (S2101 to S2103). Various parameters relating to PPP are negotiated and authenticated between the mobile node control function 205 and the access server 600, but details of the procedure are omitted here. That is, the PPP negotiation (S2102) may include a plurality of message exchanges. When the PPP negotiation is completed, the wireless mobile terminal 200 is connected to the backbone network 901 in an IP manner, and can communicate with any device connected to the backbone network by unicast. The communication between the radio mobile terminal 200 and the communication partner terminal 800 at this stage is performed by the second radio base station both in the uplink (direction transmitted from the radio mobile terminal 200) and in the downlink (direction received by the radio mobile terminal 200). 700 and the mobile communication network 902 (S2150). However, at this time point, multicast data cannot be received from the multicast communication terminal 800 yet.
[0107]
Next, when the mobile radio terminal 200 moves to the service area 1001 of the first radio base station 100, the multicast data from an arbitrary device can be received via the first radio base station 100.
[0108]
Here, the multicast router 500 periodically transmits IGMP Query to the local area network 904 by multicast (S2104). The IGMP Query is periodically transmitted to the service area 1001 of the first radio base station via the first radio base station 100.
[0109]
The first radio base station 100 periodically transmits control information such as BCCH (Broadcast Control Channel) to notify the presence of the base station through the radio (S2106). Upon receiving this BCCH and detecting a new base station (S2107), the radio link establishment function 202 of the radio mobile terminal 200 establishes a radio link with the radio link establishment function 102 of the first radio base station ( S2108). When establishing a radio link, the radio mobile terminal 200 requests the first radio base station 100 to send an IGMP Report as a proxy to the multicast router 500 and sets a multicast address of a multicast group desired to join. The control information to be included is notified to the first radio base station 100. In addition, a plurality of messages are exchanged for setting various parameters necessary for establishing a wireless link, authentication, and the like, but a method and a procedure for transmitting and receiving those messages are omitted here. In addition, a multicast address of a multicast group desired to be joined may be transmitted to the first radio base station 100 separately from when the radio link is established. In that case, if a radio link has already been established, the first radio base station 100 immediately creates an IGMP Report and transmits it to the multicast router 500.
[0110]
Here, when the first radio base station 100 detects that a radio link is established with the radio mobile terminal 200 (S2109), when the control information is received when the radio link is established, Based on the multicast address notified from the wireless mobile terminal 200 when the wireless link is established, an IGMP Report is created and transmitted to the multicast router 500 as a proxy (S2110).
[0111]
The multicast router 500 that has received the IGMP Report sets multicast routing by using a protocol such as DVMRP (Distance Vector Multicast Routing Protocol, RFC1075), so that multicast data from the multicast communication terminal 800 can be received (S2111).
[0112]
The multicast router 500 that has completed the setting of the multicast routing and can receive the multicast data transmitted by the multicast communication terminal 800 is sent from the multicast communication terminal 800 to the local area network 904 to which the interface that has received the IGMP Report is connected. Multicast data is transferred (S2112). At this time, the multicast data is transmitted as a multicast packet and received by the radio mobile terminal 200 via the first radio base station 100.
[0113]
Next, when the mobile radio terminal 200 moves from the service area 1001 of the first radio base station 100 to the service area 1002 of another first radio base station 110, it receives multicast data from the multicast communication terminal 800. , Switching to via the first radio base station 110.
[0114]
FIG. 6 shows an example of a sequence when the mobile terminal 200 moves to the foreign network 21.
[0115]
Here, similarly to the multicast router 500 (S2200), the multicast router 501 periodically transmits IGMP Query to the local area network 905 by multicast (S2201). The IGMP Query from the multicast router 501 is periodically transmitted to the service area 1002 of the first radio base station via the first radio base station 110.
[0116]
Similar to the first radio base station 100, the first radio base station 110 periodically transmits a BCCH notifying the presence of the own base station through the radio (S2202). Upon receiving this BCCH and detecting a new base station (S2203), the radio link establishment function 202 of the radio mobile terminal 200 establishes a radio link with the radio link establishment function 112 of the first radio base station 110. (S2204). When establishing a radio link, the first mobile radio base station 110 is notified of the address of the multicast group to which the mobile radio terminal 200 has joined via the previous base station and the address of the multicast group to which new subscription is desired. . In addition, a plurality of messages are exchanged for setting various parameters necessary for establishing a wireless link, authentication, etc., but the procedure is omitted here. In addition, a multicast address of a multicast group desired to be joined may be transmitted to the first radio base station 110 separately from when the radio link is established. In that case, if a radio link has already been established, the first radio base station 110 immediately creates an IGMP Report and transmits it to the multicast router 510.
[0117]
Here, when the first radio base station 110 detects that a radio link is established with the radio mobile terminal 200 (S2205), based on the multicast address notified from the radio mobile terminal 200 when the radio link is established. An IGMP Report is created and transmitted to the multicast router 500 as a proxy (S2206).
[0118]
Receiving the IGMP Report, the multicast router 510 sets multicast routing so that multicast data from the multicast communication terminal 800 can be received (S2207).
[0119]
The multicast router 500 that has completed the setting of the multicast routing and can receive the multicast data transmitted by the multicast communication terminal 800 is sent from the multicast communication terminal 800 to the local area network 905 connected to the interface that has received the IGMP Report. Multicast data is transferred (S2251). At this time, the multicast data is transmitted as a multicast packet and is received by the radio mobile terminal 200 via the first radio base station 110.
[0120]
In the above description, the radio base stations 100 and 110 send an IGMP report (instead of the radio mobile terminal 200) to the foreign agents 300 and 310 when a radio link is established with the radio mobile terminal 200 as a trigger. The radio base stations 100 and 110 cache the IGMP Query from the multicast routers 500 and 510 and confirm that the radio link has been established with the radio mobile terminal 200. As a trigger, a form in which the cached IGMP Query is transmitted via the radio (in place of the multicast routers 500 and 510) is also possible.
[0121]
Further, instead of the wireless base station, another node (server) belonging to the same network as the wireless base station detects that a wireless link is established between the wireless mobile terminal and the wireless base station, and A form in which a control message is transmitted is also possible.
[0122]
As described above, according to the present invention, a wireless mobile terminal supporting a hybrid system having a wireless interface that can be used only for reception and a wireless interface that can be used for transmission and reception uses only a wireless link that can be transmitted and received. Multicast group join processing can be performed in synchronization with switching from a communication state to a radio link capable of uplink transmission / reception and a radio link dedicated to downlink reception, and wireless handoff between base stations of the radio link dedicated to reception Therefore, multicast communication can be continued smoothly at the time of switching the communication state or at the time of handoff between base stations.
[0123]
In the above description, Mobile-IP and IGMP have been described as examples. However, the present invention can also be applied to other protocols and control messages thereof.
[0124]
Each function described above can be realized as software.
The present embodiment can also be implemented as a program for causing a computer to execute predetermined means (or for causing a computer to function as predetermined means, or for causing a computer to realize predetermined functions), The present invention can also be implemented as a computer-readable recording medium on which the program is recorded.
[0125]
Note that the configuration illustrated in the embodiment of the present invention is an example, and is not intended to exclude other configurations, and a part of the illustrated configuration may be replaced with another or one of the illustrated configurations. Other configurations obtained by omitting a part, adding another function or element to the illustrated configuration, or combining them are also possible. Also, another configuration that is logically equivalent to the exemplified configuration, another configuration that includes a portion that is logically equivalent to the exemplified configuration, another configuration that is logically equivalent to the main part of the illustrated configuration, and the like are possible. is there. Further, another configuration that achieves the same or similar purpose as the illustrated configuration, another configuration that achieves the same or similar effect as the illustrated configuration, and the like are possible.
In addition, various variations of various components illustrated in the embodiment of the present invention can be implemented in appropriate combination.
Further, the embodiment of the present invention is an invention of an invention as an individual device, an invention of two or more related devices, an invention of the entire system, an invention of components within an individual device, or a method corresponding thereto. The invention includes inventions according to various viewpoints, stages, concepts, or categories.
Therefore, the present invention can be extracted from the contents disclosed in the embodiments of the present invention without being limited to the exemplified configuration.
[0126]
The present invention is not limited to the above-described embodiment, and can be implemented with various modifications within the technical scope thereof.
[0127]
【The invention's effect】
According to the present invention, a wireless terminal equipped with a wireless interface that can be used only for reception can start processing related to the control message earlier than before without shortening the transmission cycle of the control message.
[Brief description of the drawings]
FIG. 1 is a diagram showing a network configuration example of a hybrid wireless mobile communication system according to a first embodiment of the present invention.
FIG. 2 is a wireless mobile terminal registration sequence for switching from a communication state using only a transmittable / receiveable radio link to a communication state using a radio link usable only for downlink communication according to the embodiment; Figure showing an example
FIG. 3 is a diagram showing an example of a registration sequence of wireless mobile terminals when handing off between wireless link base stations that can be used only for downlink communication according to the embodiment;
FIG. 4 is a diagram showing a network configuration example of a hybrid wireless mobile communication system according to a second embodiment of the present invention.
FIG. 5 is a wireless mobile terminal registration sequence for switching from a communication state using only a wireless link capable of transmission / reception to a communication state using a wireless link usable only for downlink communication according to the embodiment; Figure showing an example
FIG. 6 is a diagram showing an example of a registration sequence of wireless mobile terminals when handing off between wireless link base stations that can be used only for downlink communication according to the embodiment;
FIG. 7 is a diagram showing a positional relationship between a first radio base station and a second radio base station.
FIG. 8 is a diagram showing an example of a network configuration when Mobile-IP is used.
FIG. 9 is a diagram showing an example of a Mobile-IP registration sequence.
FIG. 10 is a diagram showing an example of a network configuration when using Multicast.
FIG. 11 is a diagram showing an example of an operation sequence of Multicast.
[Explanation of symbols]
First radio base station 100, 110
First interface 101, 111
Wireless link establishment functions 102 and 112
Mobile-IP control function 103,113
Second interface 104, 114
IGMP control function 105, 115
Wireless mobile terminals 200, 210
First wireless interface 201
First wireless link establishment function 202
Second wireless interface 203
Second radio link establishment function 204
Mobile node control function 205
Foreign agents 300, 310
Home Agent 400
Access server 600
Multicast routers 500 and 510
Router 520
Second radio base station 700, 701
Communication partner terminal (CN) 800
Backbone network 901
Mobile communication network 902
Local area network 903, 904, 905

Claims (13)

Radio for transmitting data to be received via the first radio interface to a radio terminal having a first radio interface usable only for reception and a second radio interface usable for transmission / reception In the base station
Setting means for establishing a radio link according to the first radio interface with the radio terminal;
Transmitting means for transmitting a predetermined control message related to a protocol higher than the wireless link when the wireless link is established with the wireless terminal by the setting means, Wireless base station. Caching means for receiving and caching the predetermined control message transmitted by a predetermined node belonging to the same network as the network to which the base station belongs, every predetermined period,
The transmission means transmits the predetermined control message cached by the caching means to the wireless terminal on behalf of the predetermined node when the wireless link is established. The radio base station according to claim 1. The radio base station according to claim 2, wherein the predetermined control message is an agent advertisement message in Mobile-IP. The radio base station according to claim 2, wherein the predetermined control message is an IGMP query message in IP multicast. A creation means for creating the predetermined control message to be transmitted by the wireless terminal to a predetermined node belonging to the same network as the network to which the base station belongs;
The transmission means transmits the predetermined control message created by the creation means to the predetermined node on behalf of the wireless terminal when the wireless link is established. The radio base station according to claim 1. The transmission means receives control information including a request to transmit the predetermined control message from the wireless mobile terminal to the predetermined node as a proxy when establishing a wireless link with the wireless terminal. When the wireless link is established, the predetermined control message created by the creating means is transmitted to the predetermined node on behalf of the wireless terminal when the wireless link is established. Item 6. The radio base station according to Item 5. The radio base station according to claim 5, wherein the predetermined control message is an agent solicitation message in Mobile-IP. The radio base station according to claim 5, wherein the predetermined control message is an IGMP report message in IP multicast. Radio for transmitting data to be received via the first radio interface to a radio terminal having a first radio interface usable only for reception and a second radio interface usable for transmission / reception In the communication control method in the base station,
A predetermined node belonging to the same network as the network to which the base station belongs is transmitted every predetermined period, receives and caches a predetermined control message related to a protocol higher than the radio link,
Establishing a wireless link according to the first wireless interface with the wireless terminal;
When the wireless link is established with the wireless terminal, the predetermined control message being cached is transmitted to the wireless terminal on behalf of the predetermined node. Communication control method. Radio for transmitting data to be received via the first radio interface to a radio terminal having a first radio interface usable only for reception and a second radio interface usable for transmission / reception In the communication control method in the base station,
Establishing a wireless link according to the first wireless interface with the wireless terminal;
When the wireless link is established with the wireless terminal, the wireless terminal should transmit to a predetermined node belonging to the same network as the network to which the base station belongs. Creating the predetermined control message according to the layer protocol;
The communication control method, wherein the created predetermined control message is transmitted to the predetermined node on behalf of the wireless terminal. A wireless terminal having a first wireless interface usable only for reception and a second wireless interface usable for transmission / reception, and transmitting data to be received to the wireless terminal via the first wireless interface A communication control method in a communication system including a radio base station for performing
The radio base station receives and caches a predetermined control message related to a protocol higher than the radio link, which is transmitted every predetermined period by a predetermined node belonging to the same network as the network to which the base station belongs. At the same time, predetermined control information that informs the existence of the own base station is periodically transmitted to the service area through the radio,
Establishing a radio link related to the first radio interface of the radio terminal between the radio base station that has received the predetermined control information and detected the radio base station, and the radio base station;
The radio base station transmits the cached predetermined control message to the radio terminal on behalf of the predetermined node when the radio link is established with the radio terminal. And a communication control method. A wireless terminal having a first wireless interface usable only for reception and a second wireless interface usable for transmission / reception, and transmitting data to be received to the wireless terminal via the first wireless interface A communication control method in a communication system including a radio base station for performing
The radio base station periodically transmits predetermined control information that informs the existence of the base station to the service area through radio,
Establishing a radio link related to the first radio interface of the radio terminal between the radio base station that has received the predetermined control information and detected the radio base station, and the radio base station;
The radio base station should transmit the radio terminal to a predetermined node belonging to the same network as the network to which the base station belongs when the radio link is established with the radio terminal. , Creating the predetermined control message related to the protocol of the higher layer than the radio link
The communication control method, wherein the created predetermined control message is transmitted to the predetermined node on behalf of the wireless terminal. In a wireless terminal having a first wireless interface usable only for reception and a second wireless interface usable for transmission / reception,
Setting means for establishing a radio link related to the first radio interface with a radio base station for transmitting data to be received via the first radio interface of the own terminal;
When establishing a radio link with the radio base station, from the radio link to which the own terminal should transmit to a predetermined node belonging to the same network as the network to which the radio base station belongs And a transmission means for transmitting control information including a request to transmit a predetermined control message related to a higher-layer protocol to the predetermined node on behalf of the own terminal. .

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