JP4099385B2 - Mobility control node, radio resource control method, communication system, and radio resource control program - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a mobile IP or a technology related to an extended system thereof, and relates to a mobility control node, a radio resource control method, a communication system, and a radio resource control program.
[0002]
[Prior art]
Conventionally, in a mobile communication system using CDMA, transmission order control of high priority packets and low priority packets is performed in units of base stations, and priority is given to packets with high priority (in terms of delay value, the maximum allowable delay is short). There has been a technique for increasing the effective capacity of the downlink channel by transmitting data automatically. However, since there is no cooperative control for resource utilization (transmission power utilization) between base stations, the effective capacity as a whole system is not always maximized.
[0003]
On the other hand, in Non-Patent Document 1, the mobile station and the base station take the lead, stop the low-priority packet transmission at the base station adjacent to the congested base station, and reduce the adjacent cell interference, This is a technique of transmitting high priority packets in a congested base station, and realizes the maximum effective capacity of the entire system.
[0004]
[Non-Patent Document 1]
“Wireless QoS for Coordinating Base Station Management Sources” 2002 IEICE General Conference B-5-71
[0005]
[Problems to be solved by the invention]
However, in the technique of Non-Patent Document 1, since both the mobile station and the base station need to implement a protocol for inter-base station cooperative control, it can be easily introduced into an existing IP-based mobile communication system. The disadvantage is not.
[0006]
In addition, packet transmission for cooperative control is required between the base station and the mobile station, and thus there is a drawback that extra radio resources must be consumed.
[0007]
The present invention has been made to solve the above-described problems, and is a mobility control node that can be easily introduced into an existing IP-based mobile communication system and can suppress consumption of radio resources required for cooperative control. An object of the present invention is to provide a radio resource control method, a communication system, and a radio resource control program.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, a mobility control node according to the present invention is a mobility control node that manages a plurality of access routers based on mobile IP or an extended method thereof, as described in claim 1, and includes at least A binding cache storing the address of the mobile node under the access router and the care-of address of the mobile node including prefix information that can identify the access router to which the mobile node is connected; and the mobile node stored in the binding cache Based on the care-of address, the congestion degree grasping means for grasping the traffic congestion degree of each access router specified by the prefix information in the care-of address, and the peripheral access of the access router where the traffic congestion degree is grasped to be a predetermined standard or more From router to mobile node Characterized in that a control means for controlling so as to temporarily limit the transmission of packets.
[0009]
The radio resource control method according to the present invention, as described in claim 9, manages a plurality of access routers based on mobile IP or an extension method thereof, and at least addresses of mobile nodes under the access router, Radio resource control method for controlling radio resources of a plurality of access routers by a mobility control node having a binding cache storing a care-of address of a mobile node including prefix information that can identify an access router to which the node is connected A congestion degree grasping step for grasping the traffic congestion degree of each access router identified by the prefix information in the care-of address based on the care-of address of the mobile node stored in the binding cache, and the traffic congestion degree Grasping above the specified standard From peripheral access router of the access routers, and having a control step of controlling so as to temporarily limit the transmission of packets to the mobile node.
[0010]
In addition, a communication system according to the present invention includes a plurality of access routers and a mobility control node that manages access routers based on mobile IP or an extended method thereof, as described in claim 13. The mobility control node is a binding cache that stores at least an address of a mobile node under an access router and a care-of address of the mobile node including prefix information that can identify an access router to which the mobile node is connected. And a congestion degree grasping means for grasping the traffic congestion degree of each access router specified by the prefix information in the care-of address based on the care-of address of the mobile node stored in the binding cache, and the traffic congestion degree is a predetermined value. Access recognized as exceeding the standard Control means for controlling to temporarily limit transmission of packets from the peripheral access router to the mobile node by restricting transfer of packets addressed to the peripheral access router to the peripheral access router of the router, By the control by, the transmission of packets from the peripheral access router to the mobile node is temporarily restricted, so that the interference with the packet transmission from the access router to the mobile node whose traffic congestion level is higher than a predetermined standard is reduced. It is characterized by.
[0011]
As described above, the present invention is characterized in that the mobility control node performs all the control (for example, grasping the degree of congestion including the priority of packets described later and suppressing transmission of low-priority packets). Since an access router (for example, a base station) and a mobile node (for example, a mobile station) in this mobile communication system can use a conventional mechanism as it is, introduction is easy. In addition, since all control is performed by the mobility control node, there is no new signal required between the access router and the mobile node, and there is no consumption of radio resources for control.
[0012]
As described above, according to the present invention, introduction into an existing IP-based mobile communication system is easy, and consumption of radio resources required for cooperative control can be suppressed.
[0013]
In addition, no new operation is required for the mobile node, and the processing load on the mobile node is light. Since the present invention relates to a mobility control node in an IP-based mobile communication system, all packets handled by the mobility control node are IP packets, and mobile node address management is also performed on an IP address basis. As described above, the present invention makes it possible to specify the access router to which each mobile node is connected from the IP address acquired by the mobile node at the destination by taking advantage of the structural features of the IP address. It is possible to know the priority of each IP packet by using the Diffserv Code Point included in the field and the upper protocol identification number of UDP / TCP. This is due to the fact that the IP address and IP header originally contain various information, and the present invention maximizes the use of only the information contained in these IP addresses and the IP header of each packet. The purpose is to perform radio resource control between access routers.
[0014]
By the way, the mobility control node according to the present invention can adopt the following configuration.
[0015]
As described in claim 2, the congestion degree grasping means may grasp the traffic congestion degree of each access router based on the number of mobile nodes connected to each access router. As described, the traffic congestion degree of each access router may be grasped based on the number of packets transferred to the mobile node connected to each access router or the total packet length. The congestion degree grasping means may grasp the traffic congestion degree of each access router for each priority class as described in claim 4.
[0016]
As described in claim 5, the control means restricts transfer of packets addressed to the peripheral access router from the mobility control node to the peripheral access router, thereby transmitting the packet from the peripheral access router to the mobile node. It is characterized by temporarily limiting. At this time, as described in the sixth aspect, when restricting transfer of packets addressed to the peripheral access router, the control means may restrict transfer of packets having a priority level equal to or lower than a predetermined level.
[0017]
More specifically, the mobility control node according to the present invention can be configured as follows. That is, as described in claim 7, the mobility control node according to the present invention is a mobility control node that manages a plurality of access routers based on mobile IP or an extended method thereof, and is at least a mobile node under the access router. And a value of a predetermined field indicating a priority class in a packet addressed to the mobile node, and a binding cache storing the care-of address of the mobile node including prefix information that can identify the access router to which the mobile node is connected A determination means for determining whether or not the packet is a low priority class packet, and a transfer destination access router is identified based on the transfer destination address of the packet, and the packet to the access router is identified. Rate calculation means for calculating the transfer data rate, and transfer data A first determination means for determining whether or not the data rate exceeds a first ratio of a predetermined radio channel capacity, and transfer when the transfer data rate exceeds a first ratio of the predetermined radio channel capacity. And a first control means for controlling the peripheral access router of the previous access router so as to temporarily limit transmission of a low priority class packet. Further, as described in claim 8, the mobility control node accesses the transfer destination when the transfer data rate exceeds a second rate smaller than the first rate in a predetermined radio channel capacity. It is desirable that the router further includes a second control unit that controls to temporarily limit transmission of the low priority class packet.
[0018]
Similarly, the radio resource control method according to the present invention can be more specifically configured as follows. That is, as described in claim 10, the radio resource control method according to the present invention manages a plurality of access routers based on mobile IP or an extension method thereof, and at least addresses of mobile nodes under the access router, Radio resource control method for controlling radio resources of a plurality of access routers by a mobility control node having a binding cache storing a care-of address of a mobile node including prefix information that can identify an access router to which the node is connected A determination step for determining whether or not the packet is a packet of a low priority class based on a value of a predetermined field representing a priority class in the packet addressed to the mobile node, and a forwarding address of the packet Based on the A rate calculation step of calculating a transfer data rate of packets to the access router, a first determination step of determining whether or not the transfer data rate exceeds a first ratio of a predetermined radio channel capacity, and a transfer data rate of A first control step of controlling the peripheral access router of the transfer destination access router to temporarily limit transmission of packets of a low priority class when a predetermined percentage of a predetermined radio channel capacity is exceeded It is characterized by having. The radio resource control method determines whether or not the transfer data rate exceeds a second rate smaller than the first rate in a predetermined radio channel capacity, as described in claim 11. A second determination step, and temporarily restricting transmission of low priority class packets to a transfer destination access router when a transfer data rate exceeds a second ratio of a predetermined radio channel capacity. It is desirable to further have a second control step for controlling.
[0019]
In the above invention, the mobility control node determines whether or not the packet is a low priority class packet based on the value of a predetermined field indicating the priority class in the packet addressed to the mobile node, and Based on the transfer destination address, the access router of the transfer destination is specified, the transfer data rate of the packet to the access router is calculated, and the transfer data rate is a first ratio (for example, 100%) of a predetermined radio channel capacity. It is determined whether or not. Here, when the transfer data rate exceeds the first ratio of the predetermined radio channel capacity, the mobility control node temporarily transmits the low priority class packet to the peripheral access router of the transfer destination access router. Control to limit.
[0020]
Thereby, in the peripheral access router of the transfer destination access router whose transfer data rate exceeds the first ratio (for example, 100%) of the predetermined radio channel capacity, the low priority class from the peripheral access router to the mobile node Is temporarily limited, interference for packet transmission from the transfer destination access router to the mobile node is reduced, and consumption of radio resources between the access routers can be reduced. In addition, since all control is performed by the mobility control node, there is no new signal required between the access router and the mobile node, and there is no consumption of radio resources for control. Similarly to the above, since an access router (for example, a base station) and a mobile node (for example, a mobile station) in an existing IP-based mobile communication system can use a conventional mechanism as it is, introduction is easy. As described above, according to the present invention, introduction into an existing IP-based mobile communication system is easy, and consumption of radio resources required for cooperative control can be suppressed.
[0021]
More specifically, in the first control step or the second control step, the low priority class packet is stored in the memory, and the memory is stored after a predetermined time. The low-priority class packet is taken out from the packet and transmitted to control the transmission of the low-priority class packet temporarily.
[0022]
By the way, the present invention can be described as the invention related to the radio resource control program as follows. That is, the radio resource control program according to the present invention manages a plurality of access routers based on mobile IP or its extension method, and at least addresses of mobile nodes under the access router, 13. A computer incorporated in a mobility control node having a binding cache storing a care-of address of a mobile node including prefix information that can identify an access router to which the node is connected. Each step of the radio resource control method according to item 1 is executed.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[0024]
[System configuration]
In FIG. 1, the block diagram of the communication system 1 of this embodiment is shown. As shown in the figure, the communication system 1 performs packet communication conforming to Hierarchical Mobile IPv6, which is an extension method of Mobile IPv6, and provides a mobile node (MN) 30 and a link for connecting the MN 30 to the packet communication network. Access router (AR) and mobility anchor point (MAP) 20 that manages the movement of the MN 30. Here, the MAPs 20A, 20B,... Are collectively referred to as MAP 20 and the MAP 20 corresponds to the mobility control node of the present invention. In addition, the area | region range 45 drawn with the dotted line in FIG. 1 shows the range where each AR provides an access link. The AR located at the center of each region range 45 is, for example, AR1 to AR19 as shown in FIG. These AR1 to AR19 are connected to the MAP 20A via a wired or wireless line.
[0025]
In the communication system 1 based on Hierarchical Mobile IPv6 as described above, a home agent (HA) 10 once transfers a packet addressed to the MN to the MAP 20, and the MAP 20 transfers the packet to the current position of the MN 30.
[0026]
In FIG. 1, AR1 to AR19 notify all MNs 30 connected to each other by including the address of MAP 20A in a Router advertisement message. The MN 30 connected to one of the ARs notifies the MAP 20A of the link care-of address (LCoA). When the MAP 20A receives a packet addressed to each MN, the MN 20A transfers the packet to each LCoA. Furthermore, when a general mobile node MNh is connected to a certain access router ARj, a unique token Noh (64 bit) is added to the node using the hardware address of the interface, etc., to the prefix Prej (64 bit) of the ARj. The care-of address LCoAjh is used (stateless address automatic setting RFC2462).
[0027]
Here, AR is a router equivalent to a base station having a radio interface, and CDMA is adopted for the radio link. The downlink radio channel capacity is determined by the maximum transmission power of each AR. That is, if the transmission power of the surrounding AR is reduced, interference caused by the transmission of the surrounding AR is reduced, and the transmission power required for each MN (equivalent to a mobile station) 30 is reduced. Packets can be transmitted to more MNs 30 within the maximum transmission power, and the downlink radio channel capacity increases.
[0028]
FIG. 2 shows the configuration of the MAP 20. As shown in the figure, the MAP 20 includes a transmission / reception interface 24 that transmits and receives data, a packet buffer unit 21 that temporarily stores packets, and a routing unit that performs encapsulation processing of packets addressed to the MN, routing of packets, and the like. 23, a binding cache 22 storing a transfer destination address (that is, a care-of address (LCoA)) and a TCP transfer stop flag for each MN as shown in FIG. 3, and an adjacent AR address for each AR as shown in FIG. An AR management table 25 that stores a UDP transfer rate and the like, and a resource management unit 26 that monitors the encapsulation process performed by the routing unit 23 and the AR management table 25 are configured.
[0029]
The above-described binding cache 22 stores a table 22A shown in FIG. 3, and this table 22A includes information on an IP address of the MN, a care-of address (LCoA) related to the MN, and a TCP transfer stop flag. . For example, in the table 22A of FIG. 3, for the MN whose IP address is MN2, LCoA is LCoA 62 and the TCP transfer stop flag is on. Therefore, the packet addressed to MN2 is transferred to the address LCoA 62, but if the packet is a TCP packet, the transmission of the packet is temporarily stopped. Specific processing will be described later.
[0030]
As shown in FIG. 4, the AR management table 25 includes an AR IP address, a prefix serving as an identifier for identifying the AR, a downstream communication capacity from the AR to the MN, an address of an adjacent AR of the AR, and a UDP. Each information of packet transfer rate is included. For example, for an AR whose IP address is AR10 (hereinafter referred to as “AR10”), the transfer rate of the UDP packet is 2.33 Mbps and exceeds the downlink capacity of 2 Mbps. Therefore, the TCP transfer stop flag (see FIG. 3) of the MN connected to the adjacent AR (that is, AR5, AR6, AR9, AR11, AR14, AR15) of the AR10 is set to ON. Specific processing will be described later.
[0031]
[Processing content]
As described above, the present invention is characterized in that the MAP 20 performs all the control (for example, grasping the degree of congestion including the priority of packets and suppressing transmission of low priority packets). In the following, as processing in the MAP 20, processing in the routing unit 23 in FIG. 9 and processing in the resource management unit 26 in FIG. 10 will be described.
[0032]
As shown in FIG. 9, the routing unit 23 first receives a received packet from the transmission / reception interface 24 (S01), and in accordance with the entry in the table 22A in the binding cache 22, Encapsulation is performed with the IP header addressed to the registered LCoA (S02). Then, the packet subjected to the encapsulation process is transmitted again from the transmission / reception interface 24 (S03).
[0033]
Note that the routing unit 23 refers to the table 22A (FIG. 3) in the binding cache 22 when performing the encapsulation processing of the packet addressed to the MN as described above, but transfers to the MN addressed with the TCP transfer stop flag set. The TCP packet to be temporarily buffered in the packet buffer unit 21. Then, when the TCP transfer flag of the MN is cleared after the valid time elapses in the table 22A, the routing unit 23 takes out the TCP packet addressed to the MN buffered in the packet buffer unit 21, and performs the capsule processing according to the table 22A. The data is transmitted to the transmission / reception interface 24.
[0034]
As shown in FIG. 10, the resource management unit 26 monitors the encapsulation process performed by the routing unit 23 (S11), and the packet is TCP or UDP depending on the value of the next header field of the encapsulated IP packet. Is determined (S12). Then, by referring to the AR management table 25, the AR address of the prefix that matches the prefix of the IP address of the transfer destination is specified, and the transfer data rate of the UDP packet or the transfer data rate of the TCP packet to each AR is determined. , Calculation is performed for each packet type obtained in the determination of S12 (S13, S14). Then, the calculation result of the transfer data rate is stored in the AR management table 25 (S15). In addition to the processing of FIG. 10, the AR management table 25 is updated every 100 msec.
[0035]
Further, the resource management unit 26 monitors the AR management table 25 (S16), and in the AR management table 25, whether or not the AR UDP transfer rate exceeds 70% of the downlink radio channel capacity of the AR. Is determined (S17). If the UDP transfer rate of the AR exceeds 70% of the downlink radio channel capacity of the AR, a TCP transfer stop flag with an effective time of 100 msec is set in the entries of all the MNs connected to the AR (S18). As a result, when the UDP transfer rate of the AR exceeds 70% of the downlink radio channel capacity of the AR, TCP packets addressed to all the MNs connected to the AR are temporarily transmitted by the routing unit 23 (effective time 100 msec has elapsed). Until it is buffered in the packet buffer unit 21. This is a method in which a UDP packet is preferentially transmitted with respect to a TCP packet within the local station of the AR.
[0036]
Further, the resource management unit 26 determines whether or not the AR UDP transfer rate exceeds 100% of the downlink radio channel capacity of the AR in the AR management table 25 (S19). If the UDP transfer rate of the AR exceeds 100% of the downlink radio channel capacity of the AR, a TCP having an effective time of 100 msec is entered for all MN entries connected to the AR adjacent to the AR on the binding cache 22. A transfer stop flag is set (S20). As a result, when the UDP transfer rate of the AR exceeds 100% of the downlink radio channel capacity of the AR, the TCP packets addressed to all the MNs connected to the adjacent AR of the AR are temporarily (effective time) by the routing unit 23. It is buffered in the packet buffer unit 21 (until 100 msec elapses). In this method, UDP packets are preferentially transmitted with respect to TCP packets by inter-base station cooperative processing.
[0037]
The effect of the processing of FIGS. 9 and 10 will be described. Assume that a UDP packet exceeding 100% of the downlink capacity of the AR 10 has been transmitted from the MAP 20A in FIG. 1 to the AR 10 shown in FIG. In this state, as shown in FIG. 6 (b), in order to transmit all the UDP packets A to D in the AR10, the power more than the maximum transmission power is required, and some UDP packets D that are not transmitted are stored in the AR10. It can be discarded due to buffer overflow. On the other hand, in AR11, even when all the UDP packets E and TCP packets F and G are transmitted as shown in FIG. 6A, the power is less than the maximum transmission power, so these UDP packets E and TCP packets F and G Is sending everything.
[0038]
Here, when the processes of FIGS. 9 and 10 are applied, the TCP packet transfer to the AR 11 adjacent to the AR 10 is temporarily stopped by the process of S20 of FIG. 10 as indicated by a broken line in FIG. As shown in FIG. 8A, the transmission power of the AR 11 decreases. As a result, the interference to the AR 10 due to the packet transmission of the AR 11 is reduced, and the power required for the AR 10 to transmit each packet is reduced. As a result, as shown in FIG. All UDP packets A to D can be transmitted.
[0039]
As described above, coordinated control of radio resources between ARs can be performed smoothly, and consumption of radio resources required for coordinated control can be suppressed. Further, the MAP performs all the control, and the AR and MN in the existing IP-based communication system can use the conventional mechanism as it is, so that the introduction is easy.
[0040]
Note that the TCP packets addressed to the MN connected to the AR10 and AR11 buffered in the packet buffer unit 21 of the MAP 20 by the processing of S18 and S20 in FIG. 10 are buffered when the rate of the UDP packets transmitted from the AR10 decreases. Will be released and will be routed again to AR10 and AR11. In the above, an example of a communication system in which packet communication conforming to Hierarchical Mobile IPv6, which is an extension method of Mobile IPv6, has been described, but the present invention is also applicable to a communication system in which packet communication conforming to Mobile IPv6 is performed. Is possible. In this case, a home agent (HA) corresponds to the mobility control node of the present invention, and performs the same operation as the MAP 20 described above. Further, the present embodiment is not limited to Mobile IPv6, but may be Mobile IPv4 and other Internet protocols.
[0041]
[Configuration of radio resource control program]
Finally, a radio resource control program for causing the MAP 20 to execute the above-described processing related to radio resource control will be described. Here, the first mode of FIG. 11 related to the radio resource control method of claim 9 and the second mode of FIG. 12 related to the radio resource control method of claims 10 and 11 will be described.
[0042]
As shown in FIGS. 11 and 12, the radio resource control program 51 is stored in a program storage area 50 a formed in the recording medium 50.
[0043]
As shown in FIG. 11, the radio resource control program 51 according to the first aspect is configured to control the radio resource control process as a whole, based on the main module 51a and the care-of address of the MN stored in the binding cache. From the congestion level determination module 51b that causes the MAP 20 to execute processing for determining the traffic congestion level of each AR specified by the prefix information in the network, and the AR adjacent to the AR whose traffic congestion level is determined to be equal to or greater than a predetermined reference, MN And a control module 51c for causing the MAP 20 to execute processing for temporarily limiting packet transmission to the network.
[0044]
As shown in FIG. 12, the radio resource control program 51 according to the second mode is based on a main module 51a that performs overall control of radio resource control processing and a value of a predetermined field that represents a priority class in a packet addressed to the MN. A determination module 51d for causing the MAP 20 to execute a process for determining whether or not the packet is a low-priority class packet (for example, a TCP packet), a transfer destination AR of the packet is specified, and a packet to the AR A rate calculation module 51e for causing the MAP 20 to execute a process for calculating the transfer data rate of the MAP 20 and a process for determining whether or not the transfer data rate exceeds a first ratio (for example, 100%) of a predetermined radio channel capacity. The first determination module 51f to be executed by the mobile station and a transfer data rate of a predetermined wireless channel capacity A first control module 51g that causes the MAP 20 to execute processing for temporarily restricting transmission of a low priority class packet to the adjacent AR of the transfer destination AR when the first ratio of The second determination module 51h that causes the MAP 20 to execute a process of determining whether or not the transfer data rate exceeds a second ratio (for example, 70%) smaller than the first ratio in the predetermined radio channel capacity. When the transfer data rate exceeds the second ratio of the predetermined radio channel capacity, the MAP 20 executes processing for controlling the transfer destination AR to temporarily limit the transmission of the low priority class packet. And a second control module 51i to be configured.
[0045]
The wireless resource control program 51 of the above two aspects is partially or entirely transmitted to another device via a transmission medium such as a wired or wireless communication line, or via a recording medium such as a memory stick. It is also possible to adopt a configuration that is copied to another device and recorded (including installation) in the other device.
[0046]
【The invention's effect】
As described above, according to the present invention, the mobility control node performs all control (for example, grasping the degree of congestion including packet priority and suppressing transmission of low priority packets). Since an access router and a mobile node in an IP-based mobile communication system can use a conventional mechanism as it is, introduction is easy. In addition, since all control is performed by the mobility control node, there is no new signal required between the access router and the mobile node, and there is no consumption of radio resources for control. For this reason, according to the present invention, introduction into an existing IP-based mobile communication system is easy, and consumption of radio resources required for cooperative control can be suppressed.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a communication system in an embodiment of the invention.
FIG. 2 is a configuration diagram of a MAP.
FIG. 3 is a table showing an example of a table stored in a binding cache.
FIG. 4 is a table showing an example of an AR management table.
FIG. 5 is a diagram illustrating a state in which a UDP packet exceeding 100% of the capacity has been transmitted from the MAP to the AR 10;
6A is a diagram showing a state of radio resource consumption in the AR 11 in FIG. 5; FIG. 6B is a diagram showing a state of radio resource consumption in the AR 10 in FIG. 5;
7 is a diagram showing a state after the present invention is applied to the state of FIG.
8A is a diagram showing a state of radio resource consumption in the AR 11 in FIG. 7, and FIG. 8B is a diagram showing a state of radio resource consumption in the AR 10 in FIG. 7;
FIG. 9 is a flowchart showing the contents of processing in the routing unit.
FIG. 10 is a flowchart showing the contents of processing in a resource management unit.
FIG. 11 is a diagram showing a first configuration aspect of a radio resource control program according to the present invention.
FIG. 12 is a diagram showing a second configuration aspect of the radio resource control program according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Communication system, 10 ... Home agent, 20 ... Mobility control node, 21 ... Packet buffer part, 22 ... Binding cache, 22A ... Table, 23 ... Routing part, 24 ... Transmission / reception interface, 25 ... AR management table, 26 ... Resource Management unit, 30 ... mobile node, 40 ... access router, 45 ... area range, 50 ... recording medium, 50a ... program storage area, 51 ... radio resource control program, 51a ... main module, 51b ... congestion degree grasping module, 51c ... Control module, 51d ... determination module, 51e ... rate calculation module, 51f ... first determination module, 51g ... first control module, 51h ... second determination module, 51i ... second control module.

Claims (14)

A mobility control node that manages a plurality of access routers based on mobile IP or an extended method thereof,
A binding cache storing at least an address of a mobile node under the access router and a care-of address of the mobile node including prefix information that can identify an access router to which the mobile node is connected;
Based on the care-of address of the mobile node stored in the binding cache, a congestion degree grasping means for grasping the traffic congestion degree of each access router specified by the prefix information in the care-of address,
Control means for controlling to temporarily limit transmission of packets to the mobile node from the peripheral access router of the access router whose traffic congestion degree is grasped to be equal to or higher than a predetermined reference;
Mobility control node with The congestion degree grasping means is:
2. The mobility control node according to claim 1, wherein the degree of traffic congestion of each access router is ascertained based on the number of mobile nodes connected to each access router. The congestion degree grasping means is:
2. The mobility control node according to claim 1, wherein the traffic congestion degree of each access router is grasped based on the number of packets transferred to the mobile node connected to each access router or the total packet length. The congestion degree grasping means is:
4. The mobility control node according to claim 2, wherein the traffic congestion degree of each access router is further grasped for each priority class. The control means includes
The transmission of packets from the peripheral access router to the mobile node is temporarily restricted by restricting transfer of packets addressed to the peripheral access router from the mobility control node to the peripheral access router. The mobility control node according to any one of 1 to 4. The control means includes
6. The mobility control node according to claim 5, wherein when the transfer of packets addressed to the peripheral access router is restricted, the transfer of packets having a priority level equal to or lower than a predetermined level is restricted. A mobility control node that manages a plurality of access routers based on mobile IP or an extended method thereof,
A binding cache storing at least an address of a mobile node under the access router and a care-of address of the mobile node including prefix information that can identify an access router to which the mobile node is connected;
Determining means for determining whether or not the packet is a low priority class packet based on a value of a predetermined field indicating a priority class in the packet addressed to the mobile node;
A rate calculating means for identifying a transfer destination access router based on a transfer destination address of the packet and calculating a transfer data rate of the packet to the access router;
First determination means for determining whether or not the transfer data rate exceeds a first ratio of a predetermined radio channel capacity;
When the transfer data rate exceeds a first ratio of a predetermined wireless channel capacity, the peripheral access router of the transfer destination access router is controlled to temporarily limit the transmission of the low priority class packet. 1 control means;
Mobility control node with When the transfer data rate exceeds a second ratio smaller than the first ratio in the predetermined radio channel capacity, the low-priority class packet is temporarily transmitted to the transfer destination access router. The mobility control node according to claim 7, further comprising second control means for controlling to limit. A plurality of access routers are managed based on Mobile IP or its extension method, and at least an address of a mobile node under the access router and a mobile node including prefix information that can identify an access router to which the mobile node is connected A radio resource control method for controlling radio resources of the plurality of access routers by a mobility control node provided with a binding cache storing care-of addresses,
Based on the care-of address of the mobile node stored in the binding cache, a congestion degree grasping step for grasping the traffic congestion degree of each access router specified by the prefix information in the care-of address,
A control process for controlling to temporarily limit the transmission of packets to the mobile node from the peripheral access router of the access router whose traffic congestion degree is determined to be equal to or higher than a predetermined standard;
A radio resource control method comprising: A plurality of access routers are managed based on Mobile IP or its extension method, and at least an address of a mobile node under the access router and a mobile node including prefix information that can identify an access router to which the mobile node is connected A radio resource control method for controlling radio resources of the plurality of access routers by a mobility control node provided with a binding cache storing care-of addresses,
A determination step of determining whether the packet is a packet of a low priority class based on a value of a predetermined field representing a priority class in a packet addressed to a mobile node;
A rate calculating step of identifying a transfer destination access router based on the transfer destination address of the packet and calculating a transfer data rate of the packet to the access router;
A first determination step of determining whether or not the transfer data rate exceeds a first ratio of a predetermined radio channel capacity;
When the transfer data rate exceeds a first ratio of a predetermined wireless channel capacity, the peripheral access router of the transfer destination access router is controlled to temporarily limit the transmission of the low priority class packet. 1 control process;
A radio resource control method comprising: A second determination step of determining whether or not a transfer data rate exceeds a second ratio smaller than the first ratio in a predetermined radio channel capacity;
A second control step of controlling, when the transfer data rate exceeds a second ratio of a predetermined radio channel capacity, to temporarily limit transmission of a low priority class packet to a transfer destination access router; The radio resource control method according to claim 10, further comprising: In the first control step or the second control step,
The low priority class packet is stored in the memory, and after a predetermined time, the low priority class packet is extracted from the memory and transmitted, thereby controlling the transmission of the low priority class packet temporarily. 12. The radio resource control method according to claim 10 or 11, wherein: A communication system including a plurality of access routers and a mobility control node that manages the access routers based on mobile IP or an extension method thereof,
The mobility control node
A binding cache storing at least an address of a mobile node under the access router and a care-of address of the mobile node including prefix information that can identify an access router to which the mobile node is connected;
Based on the care-of address of the mobile node stored in the binding cache, a congestion degree grasping means for grasping the traffic congestion degree of each access router specified by the prefix information in the care-of address,
By restricting the forwarding of packets addressed to the peripheral access router to the peripheral access router of the access router whose traffic congestion level is determined to be equal to or higher than a predetermined standard, transmission of packets from the peripheral access router to the mobile node is temporarily Control means for controlling to limit,
By the control by the control means, the transmission of packets from the peripheral access router to the mobile node is temporarily restricted, so that there is no interference with the packet transmission from the access router to the mobile node having a traffic congestion level equal to or higher than a predetermined standard. Reduced,
A communication system characterized by the above. A plurality of access routers are managed based on Mobile IP or its extension method, and at least an address of a mobile node under the access router and a mobile node including prefix information that can identify an access router to which the mobile node is connected A computer built in a mobility control node having a binding cache storing a care-of address,
A radio resource control program that causes each step of the radio resource control method according to any one of claims 9 to 12 to be executed.

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