JP4905499B2 - Mobility management method and mobile terminal - Google Patents

Description

  The present invention supports a change of a home address that occurs when a mobile terminal moves (roams) between mobile communication networks having different service forms in a mobile communication system for access to the Internet. The present invention relates to a mobility management method and a mobile terminal that enable communication with one address.

Mobile IP is one of the mobility management methods in the Internet system, and Mobile IPv4 corresponding to IPv4 (Internet Protocol Version 4) is standardized by RFC3220 (IP Mobility Support). Mobile IPv6 corresponding to IPv6 (Internet Protocol Version 6) is still being standardized in the Internet draft draft-ietf-mobileip-ipv6 (Mobility Support in IPv6). These protocols enable communication using the same address even when the mobile terminal moves between different networks.

  In mobile IPv6, when a mobile terminal moves away from a home link, the mobile terminal temporarily acquires the prefix information of the currently connected link from the network information transmitted from the access router of the currently connected link. A care-of address to be used for the purpose is generated. After that, by sending a binding update message to the home agent, the care-of address is registered as the primary care-of address with the home agent on the home link of the mobile terminal. After receiving the binding update message from the mobile terminal, the home agent creates or updates a binding cache that associates the home address with the care-of address.

  The home agent refers to the binding cache, performs proxy reception of a packet transmitted to the home address on the home link of the mobile terminal, encapsulates the received packet, and forwards the packet to the care-of address of the mobile terminal. Do. The mobile terminal can decapsulate the packet transferred by the home agent and receive a packet addressed to the home address of the mobile terminal.

  Conventionally, as a mobile communication method in this field, for example, there is a method described in Patent Document 1. FIG. 23 shows a conventional mobile communication method described in Patent Document 1.

  In FIG. 23, a plurality of mobile communication networks are composed of a private automatic branch exchange (PABX) 2303, a home base station (HBS) 2305, a digital enhanced cordless long distance communication (DECT) 2306, and a mobile terminal 2304. The network is connected by a mobile subscriber relay station (M-TVSt) 2301. Then, the home data bank (HDB) 2302 acquires and manages the call number of the mobile terminal 2304 used in each network via the private automatic branch switching equipment (PABX) 2303 in each mobile communication network, and associates it with the representative number. It is possible to transfer incoming calls from outside.

Japanese translation of PCT publication No. 2002-503415 (pages 5-8, FIG. 1)

  However, in a conventional mobile communication system using mobile IP, there is a one-to-one relationship between mobile terminals and home agents, and home agents are installed and managed for each domain of mobile communication operators. In such a situation, when the mobile terminal moves between domains, different home addresses are assigned depending on the destination domain, and in the communication from the outside, the home address of the mobile terminal accessible by the external terminal is selected, that is, It is necessary to know the operator domain that the mobile terminal is currently accessing, which imposes a reduction in communication efficiency and convenience.

  It is also possible to support changing home addresses using DNS that manages the correspondence between host names and addresses of mobile terminals, especially dynamic DNS that can be updated dynamically. It takes several minutes or more for the system to stabilize, and there are many problems in quickly responding to the movement of the mobile terminal.

  In Patent Document 1, in a closed communication network for a mobile communication network such as GSM, the home data bank (HDB) 2302 and the private automatic branch switching equipment (PABX) 2303 of each communication network perform an association. Yes. However, the Internet, which is a free distributed network including these mobile communication networks, has a problem of lack of flexibility.

  The present invention solves the above-mentioned conventional problems, and even when the home address of a mobile terminal is changed by moving (roaming) between mobile communication networks having different service forms for each communication carrier, It is an object of the present invention to provide a mobility management method and a mobile terminal that can flexibly cope with the Internet, which is a distributed network, and can secure incoming calls from outside using a representative home address.

  In order to solve the above problems, in the present invention, in a mobile communication system using mobile IP, the mobile terminal determines a main home agent (main home agent) and a home address (main home address), and the mobile terminals have different services. When moving to the network of the form, the home address (subhome address) used in the destination network domain is registered as a care-of address in the main home agent. When accessing from the outside, by using the main home address, even if the mobile terminal moves between domain networks and is assigned a different home address, it can communicate with the outside using the main home address. In addition, even when using DNS, by registering the main home address, it is not necessary to register local home address changes caused by movement between domain networks. It becomes.

  According to the present invention, even when moving (roaming) between mobile communication networks having different service forms, incoming calls from outside can be secured using a representative home address.

The figure which shows the structure of the network in the mobile communication system which concerns on 1st embodiment of this invention. The figure which shows the structure of the network in the mobile communication system which concerns on 1st embodiment of this invention. The figure which shows the structure of the network in the mobile communication system which concerns on 1st embodiment of this invention. The figure which shows the 1st structure of the mobile terminal which concerns on 1st embodiment of this invention. The figure which shows the 2nd structure of the mobile terminal which concerns on 1st embodiment of this invention. The figure which shows the 1st structure of the home agent apparatus which concerns on 1st embodiment of this invention. The figure which shows the 2nd structure of the home agent apparatus which concerns on 1st embodiment of this invention. The figure which shows the 1st structure of the access point apparatus which concerns on 1st embodiment of this invention. The figure which shows the 2nd structure of the access point apparatus which concerns on 1st embodiment of this invention. The flowchart which shows operation | movement of the mobile terminal which concerns on 1st embodiment of this invention. The flowchart which shows operation | movement of the home agent apparatus which concerns on 1st embodiment of this invention. (A) Flow diagram showing information providing operation of access point device according to first embodiment of the present invention (b) Flow diagram showing information providing operation of access point device according to the first embodiment of the present invention The flowchart which shows the information acquisition operation | movement of the access point apparatus which concerns on 1st embodiment of this invention. The figure which shows the structure of the domain network which concerns on 1st embodiment of this invention. The figure which shows an example of the home agent list which concerns on 1st embodiment of this invention The figure which shows the structure of the home agent information provision apparatus which concerns on 1st embodiment of this invention. (A) The figure which shows an example of the binding cache which the conventional home agent apparatus manages (b) The figure which shows an example of the binding cache which the home agent apparatus which concerns on 1st embodiment of this invention manages The figure which shows an example of the binding update list which the mobile terminal device which concerns on 1st embodiment of this invention manages. The figure which shows the packet flow from the external terminal by 1st embodiment of this invention The figure which shows the structure of the mobile communication system by 2nd embodiment of this invention. The figure which shows the binding update message in Mobile IP which concerns on 1st embodiment of this invention. The figure which shows the binding ack message in Mobile IP which concerns on 1st embodiment of this invention. Configuration diagram of a conventional mobile communication system

The mobility management method according to the present invention communicates with an access point device arranged in a subnet configuring a domain network, and moves between other subnets in the same domain network and between domain networks having different service forms. A main home agent selection step of selecting a main home agent device that performs location management of the mobile terminal;
A determination step of determining whether the movement is between subnets in the same domain network or between domain networks having different service forms, depending on whether the link layer or communication medium used by the mobile terminal is changed; ,
A first registration step in which the mobile terminal registers the main home address and subhome address of the mobile terminal in the main home agent device when it is determined that the mobile terminal has moved between domain networks having different service forms; With
In the first registration step, at least one of the link layers of the mobile terminal changes from the invalid state to the valid state, and the subhome agent device is arranged in the domain network connected through the link layer in the valid state, and the mobile terminal Has acquired the home prefix information, the mobile terminal registers the main home address and the subhome address of the mobile terminal in the main home agent device .

As a result, even when a mobile terminal moves between domain networks, it is always possible to access the mobile terminal from the outside using the same address, that is, the main home address. Thus, it is possible to eliminate the confusion caused when the home address changes, and to realize consistent mobile communication.
Furthermore, a movement detection process in a short time can be realized as compared with a case where movement detection is performed by detecting a change in IP address.

  In addition, in the mobility management method according to the present invention, the mobile terminal stores in advance information related to home agent devices that are candidates for the first home agent device.

  As a result, the mobile terminal can acquire information on the main home agent such as the IP address and the main home address in advance, thereby realizing a quick location registration process at the destination.

  The mobility management method according to the present invention further includes a step in which the mobile terminal acquires information on a home agent device that is a candidate for the first home agent device from a domain network.

  As a result, only the information necessary for the destination domain network is acquired each time, so that the consumption of the memory of the mobile terminal can be suppressed.

  Further, in the mobility management method according to the present invention, in the home agent determination step, the mobile terminal switches the first home agent device from information related to the home agent device as necessary.

  As a result, it is possible to flexibly cope with a response when a home agent fails and a load balancing measure in the home agent.

  In the mobility management method according to the present invention, in the home agent determination step, the mobile terminal determines a first home agent device from information related to the home agent device based on a priority that is one of the information. Yes.

  As a result, the load on the network and the home agent can be predicted, and an advantage in network management can be secured.

  In the mobility management method according to the present invention, in the home agent determination step, the first home agent device is determined from the information related to the home agent device based on the frequency with which the mobile terminal accesses the home agent device.

  As a result, a main home agent suitable for the mobility characteristics of the mobile terminal can be selected. In particular, a transmission delay during location registration can be reduced, and an improvement in processing efficiency can be achieved.

  In addition, the mobility management method according to the present invention provides a link that has been enabled when at least one of the link layers of the mobile terminal has changed from the disabled state to the enabled state and an IP address has been acquired. A registration request step for requesting registration to a home agent device arranged in a domain network connected through the layer, and performing a subhome address registration step when the home agent device grants the registration request; .

  As a result, movement detection processing can be realized in a shorter time than when movement detection is performed by detecting a change in IP address.

A mobile terminal according to the present invention communicates with an access point device arranged in a subnet that constitutes a domain network, and moves between other subnets in the same domain network and between domain networks having different service forms. A main home agent selection unit for selecting a main home agent device for performing location management;
Network layer communication that determines whether the mobile terminal is moving between subnets in the same domain network or moving between domain networks of different service types, depending on whether the link layer or communication media used by the mobile terminal is changed A processing unit;
A home agent registration unit that registers the main home agent address and subhome address of the mobile terminal in the main home agent device when it is determined that the service network has moved between different domain networks ;
The home agent registration unit is arranged in a domain network connected through the link layer in which at least one of the link layers of the mobile terminal has an invalid state and is in a valid state. When home prefix information is acquired, the main home address and subhome address of the mobile terminal are registered in the main home agent device.

As a result, even when a mobile terminal moves between domain networks, it is always possible to access the mobile terminal from the outside using the same address, that is, the main home address. Thus, it is possible to eliminate the confusion caused when the home address changes, and to realize consistent mobile communication.
Furthermore, a movement detection process in a short time can be realized as compared with a case where movement detection is performed by detecting a change in IP address.

  The mobile terminal according to the present invention further includes a home domain storage unit that stores a home agent list that is information about home agent devices that are candidates for the first home agent device, and the main home agent selection unit is a home agent selection unit. Select the first home agent device from the list.

  As a result, the mobile terminal can acquire information on the main home agent such as the IP address and the main home address in advance, thereby realizing a quick location registration process at the destination.

  In the mobile terminal according to the present invention, the main home agent selection unit acquires information on the home agent device from the domain network and stores it in the home domain storage unit.

  As a result, only the information necessary for the destination domain network is acquired each time, so that the consumption of the memory of the mobile terminal can be suppressed.

  In the mobile terminal according to the present invention, the main home agent selection unit switches the first home agent device from the home agent list stored in the home domain storage unit as necessary.

  Accordingly, by selecting or reselecting the main home agent as necessary, it is possible to flexibly cope with a response when a home agent fails or a load balancing measure in the home agent.

  In the mobile terminal according to the present invention, the main home agent selection unit selects the first one based on the priority that is one of information related to the home agent device from the home agent list stored in the home domain storage unit. Select the home agent device.

  As a result, the load on the network and the home agent can be predicted, and an advantage in network management can be secured.

  In the mobile terminal according to the present invention, the main home agent selection unit selects a home agent device whose frequency of access is greater than or equal to a predetermined value from the home agent list stored in the home domain storage unit. Select as device.

  As a result, a main home agent suitable for the mobility characteristics of the mobile terminal can be selected. In particular, a transmission delay during location registration can be reduced, and an improvement in processing efficiency can be achieved.

  In addition, the mobile terminal according to the present invention performs a registration request to the second home agent device through the link layer in which the home agent registration unit has changed from the invalid state to the valid state, and permits the registration request by the second home agent device. Is received, the notification of the second home address is started to the first home agent device.

  As a result, movement detection processing can be realized in a shorter time than when movement detection is performed by detecting a change in IP address.

  In the mobile terminal according to the present invention, when the mobile IP processing unit receives a multiplex encapsulated packet, the source address described in the innermost header is used as the location registration destination.

  As a result, the addresses of the home agent devices and access point devices that have already been registered are not redundantly registered, so that wasteful consumption of resources of the home agent device can be prevented.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the same component is attached | subjected and shown with the same code | symbol.

(Embodiment 1)
Embodiment 1 of the present invention will be described with reference to FIGS.

  1 to 3 and 14 are diagrams showing a network configuration in a mobile communication system according to the present invention. 1 to 3, domain networks 1, 2, and 3 are domain networks having different service forms. In particular, the domain network 1 is a home domain network selected and determined by a mobile terminal (MN) 10, and the domain network 2 Reference numeral 3 denotes an external domain network. Home agent devices (HA) 50-1, 50-2, and 50-3 manage the domain networks 1, 2, and 3, respectively. In particular, the home agent device 50-1 manages the home domain network of the mobile terminal 10. Main home agent device (M-HA). The home agent devices 50-2 and 50-3 are subhome agent devices (HA-1 and HA-2) arranged in a domain network other than the home domain network. The domain network system server (DNS) 20 associates host names on the Internet with IP addresses, and associates IP addresses and host names of home agent devices 50-1 and mobile terminals 10 belonging to the domain network 1. The domain networks 2 and 3 may be defined as external domain networks, and home agent devices in the external domain network may be defined as subhome agent devices 50-2 and 50-3.

  Further, each of the domain networks 1, 2, and 3 has a configuration shown in FIG.

  In FIG. 14, the access point device (AP) 60 performs wireless communication with the mobile terminal 10. However, the present invention is not limited to this, and communication may be performed using a wired line, and the present invention does not limit it. . The local network 100 is a subnetwork laid in the domain network.

  Further, the home agent information providing server device (HIS) 70 has a function of providing the mobile terminal 10 with information related to the home agent device 50 placed in the domain network 1.

  The operation and effect of the mobility management method in the mobile communication system configured as described above will be described below.

  First, the mobile terminal 10 designates the domain network 1 as a home domain network from among the plurality of domain networks 1, 2, and 3, and uses the home agent device 50-1 as a main home agent for managing the address of the mobile terminal 10. select. This main home agent corresponds to the first home agent device.

  Next, the home agent device 50-1 assigns to the mobile terminal 10 a home address that can be used in this domain network. Then, the assigned home address is defined as a main home address in the binding cache. This main home address corresponds to the first home address.

  The mobile terminal 10 requests the DNS 20 to register this home address. In response to this request, the DNS 20 registers the name of the requested mobile terminal 10 and the home address in association with each other.

  Next, the case where the mobile terminal 10 moves in the home domain network (intersubnet movement) will be described with reference to FIG.

  First, in the newly moved subnet, the mobile terminal 10 includes at least a newly acquired care-of address CoA-M and a main home address HoA-M, and sends a registration request message according to the mobile IP procedure to the main home agent device 50-. 1 to send a packet.

  Next, when the main home agent device 50-1 receives a valid registration request message (A1), the main home agent device 50-1 updates the entry content corresponding to the mobile terminal 10 in its own binding cache, and sends a registration response message to the mobile terminal 10. A packet is sent back to (A2).

  Thereafter, the data packet addressed to the home address HoA-M of the mobile terminal 10 is tunnel-transferred by the main home agent device 50-1 to the care-of address CoA-M of the mobile terminal 10 registered in the binding cache (A2). Correctly transferred to the mobile terminal 10.

  Next, the operation when the mobile terminal 10 leaves the domain network 1 that is the home domain network and moves to the external domain network 2 under the control of the subhome agent device 50-2 (201) will be described using FIG. .

  First, the mobile terminal 10 connects to a subnet in the external domain network 2 and generates a care-of address CoA-1 based on network information of the moved subnet. The network information is distributed by, for example, a router advertisement packet. When the mobile terminal 10 recognizes that the connected domain network 2 is not the home domain network, the mobile terminal 10 acquires the subhome address HoA-1. This subhome address corresponds to the second home address.

  The care-of address CoA-1 may be generated from the network information by the mobile terminal 10 as described above, or may be assigned from the network using a protocol such as DHCP (Dynamic Host Configuration Protocol).

  The acquisition of the subhome address HoA-1 may be performed based on the information acquired from the connected access point device 60, or based on the information acquired from the home agent information providing server device 70 connected to the network. You may go. Specifically, the mobile terminal 10 transmits an inquiry packet to the access point device 60 or the home agent information providing server device 70, and the access point device 60 or the home agent information providing server device 70 responds to the mobile terminal 10 as a response. A response packet including the contents of the home agent list as shown in FIG. 15 is returned. Alternatively, the mobile terminal 10 receives and uses a data packet including the contents of the home agent list that is periodically broadcast or multicast by the access point device 60 or the home agent information providing server device 70. Here, information about the home agent device shown in FIG. 15 will be described below.

  The IP address 141 is the address of the home agent device, the preference 142 is a priority suitable for selection determined from the remaining resources and load state of the home agent device, and the lifetime 143 is the remaining operating time of the home agent device 50. The home prefix 144 indicates a list of home prefixes managed by the home agent device 50. Further, when home address assignment is performed for the mobile terminal 10, the assigned home address may be described.

  Such information acquired by the mobile terminal 10 is information of content corresponding to the home agent list to the last, and specifically, information regarding the home agent device 50 can be acquired. The mobile terminal 10 selects one home agent device 50 by any one of the selection method based on the priority 142, the highest one in the list, or the random selection. .

  As shown in FIG. 15, when home prefix information is included in the home agent list, the home address HoA-1 may be generated and acquired based on the corresponding home prefix. The home prefix information is added to the description items of the home agent list defined by the conventional mobile IP procedure according to the present invention, and one or more home prefixes managed by each home agent are added to the home agent list. It is described in the home prefix column.

  The mobile terminal 10 is not limited to this method, and the mobile terminal 10 may use a mobile prefix solicitation / advertisement (Mobile Prefix Solicitation / Advertisement) method, a dynamic home agent address discovery (Dynamic Home Agent). The home agent list may be acquired and the home address HoA-1 may be generated and acquired using the Address Discovery protocol.

  Next, the mobile terminal 10 registers the newly acquired care-of address CoA-1 together with the subhome address HoA-1 in the home agent device 50-2 (B1). Further, the mobile terminal 10 registers the sub home address HoA-1 as a care-of address in the main home agent device 50-1 together with the main home address HoA-M (B2).

  Next, when the main home agent device 50-1 and the subhome agent device 50-2 receive a packet including a registration request message from the mobile terminal 10 according to the same procedure as in the case of movement between subnets, the main home agent device 50-1 and the subhome agent device 50-2 update their binding caches. Then, a packet including a registration response message is transmitted to the mobile terminal 10.

  Thereafter, a packet addressed to the main home address HoA-M of the mobile terminal 10 is first received by the main home agent device 50-1 as a proxy, and the main home agent device 50-1 refers to its own binding cache, The address is transferred to the subhome address HoA-1 registered as the care-of address CoA (B3).

  The subhome agent device (HA-1) 50-2 receives the packet addressed to the subhome address HoA-1 as a proxy, and the subhome agent device 50-2 refers to the binding cache of its own station. The address is transferred to the address CoA-1 (B4), and finally transferred to the mobile terminal 10 in the domain network 2 correctly.

  The packet transfer mode during this period will be described below with reference to FIG.

First, the packet sent to the main home address HoA-M of the mobile terminal 10 (with the header 1 (201)) transmitted by the external terminal (CN) 80 is received by proxy by the main home agent device 50-1. The tunnel is forwarded to the home address HoA-S of the visited domain registered in the binding cache.
At this time, header 2 (203) is added.

  Next, the tunneled packet is received by proxy at the home agent device 50-2 in the visited domain, and is tunneled to the CoA of the mobile terminal 10. At this time, a header 3 (206) is further added.

  Next, the mobile terminal 10 receives the double-encapsulated transfer packet, recognizes that the source address described in the innermost header 1 (204) is that of the external terminal CN, and if necessary Request registration processing to the main home agent device. The other addresses obtained from the header 2 (205) and the header 3 (206) are not registered because they are already registered. Thereby, waste of resources in the mobile terminal 10 and the home agent device 50 can be suppressed.

  When the mobile terminal 10 moves in the external domain network 2 (intersubnet movement), a registration request message is transmitted only to the subhome agent device 50-2. Thereafter, in the movement in the external domain network, a registration request is made only to the home agent device that manages the domain.

  Next, the operation when the mobile terminal 10 leaves the foreign domain network 2 and moves to the foreign domain network 3 under the jurisdiction of the home agent 50-3 (301) will be described using FIG.

  First, the mobile terminal 10 connects to a subnet in the external domain network 3 and generates a care-of address CoA-2 based on the network information of the moved subnet. Further, when the mobile terminal 10 recognizes that the connected external domain network 3 is not the home domain network and is not the foreign domain network 2 that has been located so far, the mobile terminal 10 acquires the subhome address HoA-2.

  The care-of address CoA-2 may be generated from the network information by the mobile terminal 10 in the same way as when moving to the domain network 2, or assigned from the network using a protocol such as DHCP (Dynamic Host Configuration Protocol). You may receive.

  Further, the subhome address HoA-2 can be acquired by the same method as that acquired in the domain network 2.

  Next, the mobile terminal 10 registers the newly acquired care-of address CoA-2 together with the subhome address HoA-2 in the home agent device 50-3 (C1). Further, the mobile terminal 10 registers the subhome address HoA-2 as a care-of address in the main home agent device 50-1 together with the main home address HoA-M (C2). When the main home agent device 50-1 and the subhome agent device 50-3 receive a packet including a registration request message from the mobile terminal 10 according to the same procedure as moving to the domain network 2, the main home agent device 50-1 and the subhome agent device 50-3 update their own binding caches, A packet including a registration response message is transmitted to the mobile terminal 10.

  Thereafter, the packet addressed to the main home address HoA-M of the mobile terminal 10 is registered as the care-of address CoA after the main home agent device 50-1 first receives the proxy in the same manner as when moving to the domain network 2. It is transferred to the subhome address HoA-2 (C3). After the subhome agent device 50-3 receives this as a proxy, the subhome agent device 50-3 transfers it to the care-of address CoA-2 (C4), and finally transfers it correctly to the mobile terminal 10.

  In addition, when the mobile terminal 10 recognizes that it is not the foreign domain network 2 that has been located until then, the mobile terminal 10 moves the mobile terminal 10 to the subhome agent device 50-2 of the foreign domain network 2 that has been previously visited. A packet including a registration deletion request message defined in the IP procedure is transmitted to request that the entry corresponding to the mobile terminal 10 in the binding cache managed by the subhome agent device 50-2 be deleted. Alternatively, similarly to the registration with the main home agent device 50-1, the sub home agent device 50-2 also has the sub home address HoA-1 as the home address and the sub home address HoA- as the care-of address. Two sets are registered (C5). As a result, the packet addressed to the subhome address HoA-1 of the mobile terminal 10 that has arrived at the subhome agent device 50-2 with a time difference can be transferred to the mobile terminal 10 without omission (C6).

  Further, for all movements, the main home agent device 50-1 or the necessary care-of address (for example, CoA-1, CoA-2) is used as the care-of address CoA in the connected subnet in accordance with the mobile IP procedure. Accordingly, it is also possible to register with the subhome agent device (in the above example, the subhome agent device 50-2) that previously belonged. However, in this case, the registration to the home agent device 50 occurs every time the subnet moves, so that the efficiency is not good. Therefore, as in the present embodiment, it is desirable to register home addresses (for example, HoA-1 and HoA-2) effective in the domain network in which they are located in the main home agent device 50-1 as care-of addresses.

  Next, the configuration and operation of each device will be described with reference to the drawings.

  First, the configuration and basic operation of the mobile terminal 10 will be described.

  FIG. 4 is a block diagram showing a configuration of the mobile terminal 10 when the mobile terminal 10 functions as a host. FIG. 5 is a block diagram showing a configuration of the mobile terminal 10 when the mobile terminal 10 functions as a router.

  4 and 5, L1 / 2 processing units 11 and 16 perform physical layer and data link layer communication processing, and L3 processing unit 12 performs network layer communication processing. The unit 13 performs upper layer processing such as TCP and UDP, the mobile IP processing unit 14 manages the movement of the mobile terminal based on the mobile IP procedure, and the application processing unit 15 controls the application. The home domain storage unit 17 stores information on the main home agent device and the home domain network, and the main home address. The main home agent selection unit 18 selects the main home agent device 50, and This requests DNS 20 to register the main home address. Stringent registration unit 19 to the main home agent apparatus 50, and performs a registration request of the destination home address (sub home address).

  In FIG. 5, only two L1 / 2 processing units 11 and 16 connected to the network are shown, but a configuration including more L1 / 2 processing units may be used. The number provided is not limited. Even when three or more L1 / 2 processing units are provided, the operation can be realized by the same configuration and the procedure described below.

  The basic operation of the mobile terminal 10 configured as described above will be described below.

  The transmission operation of the mobile terminal 10 configured as shown in FIG. 4 is as follows.

  The transmission data generated by the application processing unit 15 is transferred to the L3 processing unit 12 that performs IP protocol processing via the upper layer processing unit 13 that performs processing according to a protocol such as socket, TCP, or UDP. Thereafter, at the same time as the L3 processing unit performs IP processing, the mobile IP processing unit 14 performs additional IP header processing related to mobile IP. The transmission data subjected to these processes is further transmitted to the accessing network (hereinafter referred to as “access network”) after further performing data link protocol processing and physical layer protocol processing in the L1 / 2 processing unit 11. The

  The reception operation of the mobile terminal 10 having the host function shown in FIG. 4 is an operation reverse to the transmission operation as follows.

  That is, the L1 / 2 processing unit 11 receives a packet from the access network, and performs physical layer protocol and data link protocol processing. Thereafter, while the L3 processing unit performs IP protocol processing, the mobile IP processing unit 14 simultaneously performs additional IP header processing related to mobile IP. Subsequently, after the upper layer processing unit 13 performs upper layer processing, the data is transferred to the application processing unit 15.

  Next, the operation of the mobile terminal having the router function shown in FIG. 5 will be described below.

  First, the L1 / 2 processing unit 16 performs physical layer protocol processing and data link protocol processing on a packet received from an internal network (hereinafter referred to as “internal network”). Thereafter, the L3 processing unit performs IP protocol processing including routing processing, and transfers it to either the L1 / 2 processing unit 11 or the L1 / 2 processing unit 16. The packet received from the access network by the L1 / 2 processing unit 11 is also transferred to either the L1 / 2 processing unit 11 or the L1 / 2 processing unit 16 as a result of the routing process in the L3 processing unit 12. Here, the mobile IP processing unit 14 also performs standard mobile router processing, which is an application of the mobile IP procedure, in order to realize movement transparency of the internal network.

  When the mobile terminal 10 moves, different operations are shown for movement across subnets in the same domain network and movement between different domain networks. In any case, the care of address CoA acquired after the movement is registered with the home agent device 50 of the domain network that is in the area together with the home address HoA.

  First, the operation when the mobile terminal 10 moves across subnets in the same domain network 1 will be described with reference to FIG. 1 and FIG. FIG. 10 is a flowchart showing a processing procedure related to the present invention performed by the mobile terminal 10.

  First, the mobile terminal 10 moves in the subnet, and the L3 processing unit 12 receives network information from the router arranged in the destination subnet via the L1 / 2 processing unit 11. Then, from the network information received by the L3 processing unit 12, a care-of-address CoA effective in the subnet is generated, and the received network information and the network information of the subnet connected to the currently stored destination are A comparison is made to detect whether or not it has moved (step S11). This movement detection process can also be performed by the mobile IP processing unit 14.

  Next, it is determined whether the mobile IP processing unit 14 has moved between subnets as a result of the movement detection processing (step S11) from the L3 processing unit 12 (step S12).

  As a start condition for movement detection (step S11), in addition to the above method, a start or completion trigger of a handover process performed by a lower layer, that is, the L1 / 2 processing unit 11, may be used. At that time, the L1 / 2 processing unit 11 and the mobile IP processing unit 14 need to be connected.

  Next, when movement is detected but the subnet has not changed, that is, when the newly acquired network information is the same as the previously acquired information, the process returns to step S11.

  On the other hand, if the movement is across subnets, it is determined whether or not the destination subnet is within the same domain through domain ID and prefix information that can be acquired from network information, authentication procedures, etc. (step S13). If within the same domain, the mobile IP processing unit 14 registers the new care-of address CoA-M acquired in the subnet and the home address HoA-M valid in the domain network 1 in the home agent device 50-1 (step S1). S14).

  Note that the registration process performed by the mobile IP processing unit 14 sends a packet including a registration request message (for example, a binding update message 1000 shown in FIG. 21) defined in the mobile IP procedure to the home agent device 50-1. A mobile IP processing unit receives (A2) a packet including an operation (A1) to be transmitted and a valid registration response message (for example, a binding acknowledge message 1010 shown in FIG. 22) from the home agent device 50-1. 14 includes operations until the processing can be correctly completed. The care-of address CoA-M and the home address HoA-M are described in the mobility option in the binding update data message 1000 and the binding ack message 1010, and are notified to the home agent device 50-1.

  In addition, when the mobile terminal 10 determines whether the destination subnet is a different domain network (step S13), if the mobile terminal 10 has different link layers or communication media as shown in FIG. This may be performed depending on whether the layer or the communication medium has been changed. That is, when the mobile terminal 10 has the configuration shown in FIG. 5 and the L1 / 2 processing unit 16 is connected to an access network under a domain network different from the L1 / 2 processing unit 11, the L3 processing unit 12 At the time when the transfer destination for transmission / reception is changed from the L1 / 2 processing unit 11 to the L1 / 2 processing unit 16, it is possible to simultaneously detect that the transfer is to a different subnet and to a different domain network. it can.

  In the above description, the domain network 1 that is a domain under the control of the main home agent device 50-1 is taken as an example. However, regarding movement within the same domain network, the registration destination home is also used in the other domain network 2 or 3. Other than that, only the agent device is changed to the home agent device 50-2 or 50-3, and the same processing can be performed.

  Next, the operation when the mobile terminal 10 moves between different domain networks will be described with reference to FIG. 2 and FIG.

  When the mobile IP processing unit 14 recognizes that the mobile terminal 10 is in a different domain from the subnet moved in step S13, the mobile IP processing unit 14 acquires a valid home address HoA-1 in the domain network 2 (step S15). It is registered in the home agent device 50-2 arranged in the domain network 2 together with the care-of address CoA-1 acquired previously (step S16).

  Next, the home agent registration unit 19 registers the main home address HoA-M and the home address HoA-1 acquired in the domain 2 in the main home agent device 50-1 (step S17).

  At this time, the home domain storage unit 17 may store a binding update list for managing the registration request information, and the home agent registration unit 19 adds the main home address HoA− to the binding update list held by the mobile IP processing unit 14. An entry indicating the correspondence between M and the subhome address HoA-1 may be additionally updated. This binding update list takes the form shown in FIG. 18, and includes at least an entry 170 for the home agent device 50-2 (HA-1) in the domain network 2 and the main home agent device 50-1 (M-) in the domain 1. HA).

  The registration to each home agent device 50 performed in step S16 and step S17 is the same as the registration processing in step S14, and the registration request message is received from the home agent device 50 and the registration request message is received. The operation until the mobile IP processing unit 14 can complete the processing correctly is included. Further, the home agent registration unit 19 may independently generate and transmit a registration request message according to the mobile IP procedure, or may request the mobile IP processing unit 14 to generate and transmit a registration request message.

  Here, the mobile IP processing unit 14 may transmit a registration request message to the main home agent device 50-1 via the home agent device 50-2 in the visited domain. At this time, a reverse tunnel is applied between the mobile terminal 10 and the home agent device 50-2. At this time, the source address of the registration request message is the home address assigned in the visited domain. On the other hand, the main home agent device 50-1 transmits a registration response message to the home address in the domain where the mobile terminal 10 is located. This registration response message is substituted by the home agent device 50-2. The data is received and tunneled to the care-of address CoA-1 of the mobile terminal 10.

  As described above, the mobile terminal 10 belongs to at least one home domain network and has a main home address HoA-M that is valid in the home domain network. The mobile terminal 10 can specify a home domain network and a main home agent device in advance, and can store the information and the main home address in the home domain storage unit 17 as described above. More preferably, the unit 18 obtains a home agent list as shown in FIG. 15 from the access point device 60 or the home agent information providing server device 70, and selects an optimum one from the list. Then, the home agent list acquired by the main home agent selection unit 18 is stored in the home domain storage unit 17 and, if necessary, the preference (priority) 142 in the home agent list and the presence of each domain network. Select based on the frequency of the service area or at random.

  This selection method will be described below.

  First, the time and number of times the main home agent selection unit 18 stays in each domain network, the amount of access packets, and the like are monitored and measured, and the total value is written in the home agent list and then stored in the home domain storage unit 17. Remember. When the stay time reaches a predetermined time, the main home agent selection unit 18 sets the domain network located at that time as the home domain network. Then, the main home agent selecting unit 18 newly selects a home agent device having the highest preference 142 calculated from the load and the size of the remaining resource from among the home agent devices existing in the domain network. Select as device. Note that the home agent list may not be used as the storage destination of the total value of the stay time. In this case, a new list of home agent devices belonging to the domain selected as the home domain is obtained, or an already obtained home An entry corresponding to the home domain information (prefix, etc.) selected from the agent list can be extracted to select the main home agent device.

  Next, the main home agent selection unit 18 requests the DNS managing the address of the domain network to register the home address via the mobile IP processing unit 14.

  As described above, when the mobile terminal of the present invention moves in the domain network, the home agent device 50-1 of the home domain network is informed of the main home address and the subhome address in the domain network in which the mobile terminal is located according to the mobile IP procedure. And register as a set. As a result, communication data from the external terminal is transferred by relaying the main home agent device and the subhome agent device, so that it can be received even when moving in a domain network having a different service form. In addition, since the mobile terminal is notified of this movement from the mobile terminal, it is not necessary for the home agent apparatuses on the domain networks having different service forms to adjust each other.

  Furthermore, since the mobile terminal can select the home domain network and the main home agent device, the domain network that can receive the optimum service at the moved point can be set as the home domain network, and the convenience for the user is improved. This is particularly effective when moving between domain networks having different service configurations.

  Next, the configuration and basic operation of the home agent device 50 will be described.

  FIGS. 6 and 7 are configuration diagrams of the home agent device 50. The L1 / 2 processing units 51 and 56 perform physical layer processing and data link layer processing, and the L3 processing unit 52 performs network layer processing. The upper layer processing unit 53 performs upper layer processing such as TCP and UDP, the mobile IP processing unit 54 performs movement management of the mobile terminal, and the application processing unit 55 controls the application. Is what you do.

  In FIG. 7, only two L1 / 2 processing units 51 and 56 connected to the network are illustrated, but a configuration including more L1 / 2 processing units may be used. It does not limit the number that it has. Even when three or more L1 / 2 processing units are provided, the operation can be realized by the same configuration and the procedure described below.

  The basic operation of the home agent device 50 configured as described above will be described below.

  FIG. 11 shows a processing procedure executed by the mobile IP processing unit 54 of the home agent device 50.

  First, the mobile IP processing unit 54 performs location management of the mobile terminal 10 according to a mobile IP procedure. That is, the mobile IP processing unit 54 receives a packet from the mobile terminal 10 via the L1 / 2 processing unit 51 and the L3 processing unit 52 (step S51), and whether or not a valid registration request message is included in the packet. Is determined (step S52). If the packet contains a valid registration request message, the mobile IP processing unit 54 performs a binding cache update process (step S53).

  In the binding cache update (step S53), the following processing is performed. If there is an entry for the mobile terminal 10 in the binding cache managed by the home agent device 50, the content is updated. If there is no entry, information contained in the registration request message, for example, the home address of the mobile terminal 10 or , Create a new entry using care-of address, lifetime, and the like. Here, the data structure of the binding cache will be described. FIG. 17 (a) shows a conventional binding cache entry 150, and FIG. 17 (b) shows a binding cache entry 160 generated by the present invention.

The mobile IP processing unit 54 includes each field, that is, a home address 151 and a care of address 152 of the mobile terminal 10, a lifetime of registration request (BU Lifetime) 153, and a lifetime (BC) of this entry. The necessary items such as “Lifetime” 154, a registration request message sequence number (BU Seq. Number) 155, a registration request flag (BU Flag) 156 are described. The conventional entry 150 described the home address (HoA-1) in the home address field 151 and the address (CoA-1) of the subnet accessing the care of address field 152, but according to the present invention. The entry 160 is different in that the main address (HoA-M) is described in the home address field 151, and the home address (HoA-1) of the access destination domain network is described in the care-of address field 152. Further, the present invention is characterized in that the mobile IP processing unit 54 does not need to add any new processing regarding the contents described in the binding cache entry, and the home agent device 50 defined by the standard mobile IP. Can be used as is.

  Next, after the mobile IP processing unit 54 completes the update of the binding cache, the mobile IP processing unit 54 includes the success or failure of the binding cache update addressed to the mobile terminal 10 via the L3 processing unit 52 and the L1 / 2 processing unit 51. A registration response message is transmitted as a packet (step S54).

  On the other hand, if a valid registration request message is not included in the received packet, the mobile IP processing unit 54 performs normal IP layer processing not including the mobile IP procedure in the L3 processing unit 52 (step S57).

  If the packet received by the mobile IP processing unit 54 is not from the mobile terminal 10 in step S51, it is determined whether the packet is destined for the mobile terminal 10 (step S55).

  If the packet is addressed to the mobile terminal 10, the mobile IP processing unit 54 searches the entry related to the mobile terminal 10 in the binding cache using the home address HoA as a key. If there is an entry, the mobile IP processing unit 54 searches for the registered care-of address CoA. The received packet is encapsulated with an IP header as a destination and transmitted in the order of the L3 processing unit 52 and the L1 / 2 processing unit 51. If there is no entry, the received packet is routed to the home network connected to the home agent device 50 (step S56). For example, when the home agent device 50 has the configuration of FIG. 6, the L3 processing unit 52 and the L1 / 2 processing unit 51 are transmitted to the network in this order. When the home agent device 50 has the configuration of FIG. 2 to the home network in the order of the processing unit 56.

  On the other hand, if the packet is not addressed to the home address of the mobile terminal 10, the process proceeds to step S57.

  If the home agent device 50 has the configuration shown in FIG. 6, in step S55, the packet received by the L3 processing unit 52 by the mobile IP processing unit 54 is not addressed to the mobile terminal 10 but addressed to the home agent device 50. If it is determined that the data is transferred to the application processing unit 55 via the upper layer processing unit 53, application processing is performed. Furthermore, when it is not addressed to the home agent device 50, it is retransmitted to the network via the L1 / 2 processing unit 51 again.

  When the home agent device 50 has a plurality of physical links as shown in FIG. 7, the received packet is transferred to one of the L1 / 2 processing units 51 and 56 based on the routing table managed by the L3 processing unit 52. , Send to the network again.

  7 may further include an upper layer processing unit 53 connected to the L3 processing unit 52 and an application processing unit 55 connected to the upper layer processing unit 53. By performing the operations described with reference to FIGS. 6 and 7 in combination, the processing can be realized. That is, when the L3 processing unit 52 determines that the packet is addressed to the own station, the packet is transferred to the application processing unit 55 via the upper layer processing unit 53. If it is determined that the received packet is not addressed to the home address HoA of the mobile terminal 10 accommodated and is not addressed to the own station, the received packet is determined as L1 / L based on the routing table managed by the L3 processing unit 52. 2 Transfer to one of the processing units 51 and 56 and retransmit to the network.

  As described above, the home agent device 50 registers the location information from the mobile terminal 10 in the binding cache and transmits a packet addressed to the mobile terminal received thereafter based on the registered pinning cache. Data destined for the terminal can be accurately transferred.

  Next, the configuration and operation of the access point device 60 will be described.

  FIG. 8 shows a configuration when the access point device 60 functions as a bridge, and FIG. 9 shows a configuration when the access point device 60 functions as a router. The first network is a network to which the mobile terminal 10 is connected.

  In FIG. 8, L1 processing units 61 and 63 perform physical layer processing, and an L2 processing unit 62 performs data link layer processing of transmission / reception packets and packet relay (bridging) between the L1 processing units 61 and 63. The home agent information processing unit 64 acquires and provides home agent information using IP packets, and performs higher layer processing of layer 3 (L3) and higher. As for the upper layer processing, an upper layer processing means for performing upper layer processing of L3 or higher can be provided between the L2 processing unit 62 and the upper layer processing unit 62.

  FIG. 9 is a second block diagram of the access point device 60. The L1 / 2 processing units 65 and 67 perform physical layer processing and data link layer, and the L3 processing unit 66 performs network layer processing of transmission / reception packets. And relaying packets between the L1 / 2 processing units 65 and 67, and the home agent information processing unit 68 acquires and provides home agent information using IP packets. Upper layer processing higher than layer 4 (L4) is performed. As for the upper layer processing, an upper layer processing means for performing upper layer processing of L4 or higher can be provided between the L3 processing unit 66 and the upper layer processing unit 66.

  The operation of the access point device 60 configured as described above will be described below.

  FIG. 13 shows a processing procedure in which the access point device 60 periodically acquires home agent information and updates the stored information.

  In FIG. 13, the home agent information processing units 64 and 68 always check whether or not it is the information update timing (step S64). If it is the information update timing, an inquiry packet is generated, and the L2 processing unit 62 and L1 The data is transmitted to the second network via the processing unit 63 or via the L3 processing unit 66 and the L1 / 2 processing unit 67 (step S65). The transmission destination at this time may be an anycast address for the home agent device 50 as defined in the mobile IP procedure, or may be a unicast address for the home agent device 50. The inquiry packet may be transmitted to the first network as necessary, or may be transmitted to both the first and second networks.

  Alternatively, the entire network may be designated as the destination to be transmitted by the home agent information processing units 64 and 68 and broadcast, or the unicast address destined for the home agent device generated from the stored home prefix information may be designated. May be. Alternatively, unicast transmission may be performed to the home agent device 50. Further, the inquiry packet may conform to Dynamic Home Address Discovery defined by the mobile IP procedure. Note that the timing for updating the information may be managed using a timer or may be managed manually.

  Next, the home agent information processing units 64 and 68 are provided with at least one home agent via the L1 processing unit 63 and L2 processing unit 62, or via the L1 / 2 processing unit 67 and L3 processing unit 66. A valid response packet is received from the device 50, and the content is stored and held (step S66). The home agent information processing units 64 and 68 obtain information about the home agent device 50 shown in FIG. 15 from one or more home agent devices 50, and create entries 110 to 130 for each home agent device 50.

  The information to be stored and retained is retained at least until the next information update timing, and may be retained preliminary for a certain period after the update.

  As described above, the access point device 60 can always keep the latest home agent information by periodically acquiring information related to the home agent device 50 having jurisdiction over the domain network to be connected.

  In addition, the access point device 60 provides home agent information to the mobile terminal 10.

  Next, a processing procedure in which the home agent information processing unit 64 provides home agent information will be described.

  FIG. 12A shows a processing procedure in which the access point device 60 provides home agent information in response to a request from the mobile terminal 10, and FIG. 12B shows that the access point device 60 periodically broadcasts the home agent information. Alternatively, a processing procedure for multicasting is shown.

  In FIG. 12A, the home agent information processing units 64 and 68 are connected to the mobile terminal via the L1 processing unit 61 and the L2 processing unit 62, or via the L1 / 2 processing unit 65 and the L3 processing unit 66. The reception of the inquiry signal or packet from 10 is checked (step S61).

  Upon receiving these inquiries, the home agent information processing units 64 and 68 read out information related to the stored home agent device and generate a response signal or a packet (step S62).

  The home agent information processing units 64 and 68 send these response signals to the mobile terminal 10 via the L2 processing unit 62 and L1 processing unit 61, or via the L3 processing unit 66 and L1 / 2 processing unit 65. A packet is transmitted (step S63).

  In FIG. 12B, the home agent information processing units 64 and 68 always determine whether or not it is the timing of providing information to the mobile terminal 10 (step S71). The information relating to the home agent device stored and held earlier is read out, and a response signal or a packet is generated (step S72).

  The home agent information processing units 64 and 68 receive the mobile terminal 10 via the L2 processing unit 62 and the L1 processing unit 61, or via the L3 processing unit 66 and the L1 / 2 processing unit 65. Broadcast transmission to the network (step S73). Here, the information provision timing may be managed using a timer or may be managed manually.

  As described above, the access point apparatus of the present invention can provide home agent information in response to a request from a mobile terminal or periodically. Thereby, since the mobile terminal can acquire home agent information from the access point device located at the shortest distance, it is possible to shorten the processing time for transmitting the control data when starting communication.

  Next, the configuration and operation of the home agent information providing server device 70 will be described.

  FIG. 16 is a configuration diagram of the home agent information providing server device 70. The L1 / 2 processing unit 71 performs physical layer and data link layer processing, and the L3 processing unit 72 performs network layer processing. The home agent information processing unit 73 collects and stores home agent information related to the home agent device 50 that manages the domain network to be connected, and provides the stored home agent information to the mobile terminal 10.

  The operation of home agent information providing server apparatus 70 configured as described above will be described below.

  The home agent information processing unit 73 performs the same operation as the home agent information processing units 64 and 68 of the access point device 60.

  That is, the home agent information processing unit 73 periodically acquires information related to the home agent device 50 that has jurisdiction over the domain network to be connected by the process shown in FIG. Further, the home agent information is provided to the mobile terminal 10 periodically or in response to a request from the mobile terminal 10 by the processing shown in FIGS.

  As described above, the home agent information providing server device 70 of the present invention collectively manages information related to the home agent device, so that each access point device 60 collects the home agent information and provides it to the mobile terminal. Since it is not necessary to implement the function, the cost of the entire system can be reduced.

  Even when the mobile terminal 10 moves between a plurality of home agent devices 50 arranged in the same domain, the home agent information can be similarly provided to the mobile terminal 10 in response to a request from the mobile terminal.

  As described above, in this embodiment, even when a mobile terminal is assigned a different home address in the destination domain network, the main home agent manages the correspondence with the main home address, so that the mobile terminal moves between mobile communication networks. It is possible to support the change of the home address that occurs during (roaming) so that the external terminal is not aware of it.

  Further, since the mobile terminal can arbitrarily select the main home agent, it is possible to flexibly cope with domain networks having different service forms.

  Further, since the home address is registered with the main home agent instead of the care-of address as in the conventional mobile IP, the location registration frequency in the main home agent can be suppressed, and the load on the network can be reduced.

(Embodiment 2)
FIG. 20 shows a network configuration of the mobile communication system in the second embodiment of the present invention.

  This embodiment is different from the first embodiment in that a plurality of main home agent devices (main home agent devices 50-4 and 50-5) are set as shown in FIG. Other devices constituting the mobile communication system are the same as those described in the first embodiment.

  A mobile communication method in the mobile communication system configured as described above will be described below.

  The mobile terminal 10 holds HoA-M1 and HoA-M2 (corresponding to home agent devices 50-4 and 50-5, respectively) as main home addresses. In this case, the mobile terminal 10 registers the home address HoA-S and the care-of address CoA-S acquired by accessing the destination domain network 6 in the home agent device 50-6 of the domain network 6 (D1, D4). . At the same time, the mobile terminal 10 registers the main home address HoA-M1 and the home address HoA-S in the domain network 6 in the main home agent device 50-4 (D2, D3, D4), and the main home agent device 50-5. The home address HoA-S is registered (D5, D6, D4) in the same manner as the main home address HoA-M2.

  Thereby, the communication data addressed to the mobile terminal 10 transmitted to the home address HoA-M1 or the home address HoA-M2 is transferred to the subhome agent device 50-6, and the mobile terminal 10 is transferred from the subhome agent device 50-6. Delivered to.

  By having a plurality of main home addresses in this way, for example, a main home address used privately is accommodated in a home agent device mounted on a home gateway at home, and the main home address used for work is used as the home gateway of the company. Can be accommodated. As a result, for example, even when it is accommodated in a home agent device provided by an Internet provider connected on a business trip destination, it is possible to secure incoming calls addressed to the main home address used privately and incoming to the main home address used for work. it can.

  According to the present invention, even when moving (roaming) between mobile communication networks having different service forms, incoming calls from outside can be secured using a representative home address.

1, 2, 3, 4, 5, 6 Domain network 10 Mobile terminal 11, 16 L1 / 2 processing unit 12 L3 processing unit 13 Upper layer processing unit 14 Mobile IP processing unit 15 Application processing unit 17 Home domain storage unit 18 Main home Agent selection unit 19 Home agent registration unit 20 DNS
50, 50-1, 50-2, 50-3, 50-4, 50-5, 50-6 Home agent device 51, 56 L1 / 2 processing unit 52 L3 processing unit 53 Upper layer processing unit 54 Mobile IP processing unit 55 Application processing unit 60 Access point device 61, 63 L1 processing unit 62 L2 processing unit 64, 68 Home agent information processing unit 65, 67 L1 / 2 processing unit 66 L3 processing unit 70 Home agent information providing server device 71 L1 / 2 processing Unit 72 L3 processing unit 73 home agent information processing unit 80 external terminal 100 local network 2301 subscriber relay station 2302 home data bank 2303 private automatic branch switching equipment 2304 mobile terminal 2305 home base station 2306 digital enhanced cordless long-distance communication

Claims (20)

A mobile terminal that communicates with an access point device arranged in a subnet configuring a domain network and moves between other subnets in the same domain network and between domain networks having different service forms performs location management of the mobile terminal. A main home agent selection step of selecting a main home agent device;
Judgment to determine whether the mobile terminal is moving between the subnets in the same domain network or between different domain networks depending on whether the link layer or communication media used for communication is changed Steps,
A first registration step in which the mobile terminal registers the main home address and subhome address of the mobile terminal in the main home agent device when it is determined that the mobile terminal has moved between domain networks having different service forms. And
In the first registration step, at least one of the link layers of the mobile terminal is changed from the invalid state to the valid state, and the subhome agent device is disposed in a domain network connected through the link layer in the valid state, A mobility management method in which, when the mobile terminal acquires home prefix information, the mobile terminal registers a main home address and a subhome address of the mobile terminal in the main home agent device . The mobile terminal recognizes that the home prefix acquired in the moved domain network is different from the home prefix acquired in the source domain network, thereby confirming that the mobile terminal is moving between domain networks of different service forms. The movement management method according to claim 1, further comprising a confirmation step of confirming. A mobile terminal that communicates with an access point device arranged in a subnet configuring a domain network and moves between other subnets in the same domain network and between domain networks having different service forms performs location management of the mobile terminal. A main home agent selection step of selecting a main home agent device;
Judgment to determine whether the mobile terminal is moving between the subnets in the same domain network or between different domain networks depending on whether the link layer or communication media used for communication is changed Steps,
A first registration step in which the mobile terminal registers the main home address and subhome address of the mobile terminal in the main home agent device when it is determined that the mobile terminal has moved between domain networks having different service forms. When
When it is determined that the mobile terminal has moved between domain networks having different service forms, the mobile terminal uses a care-of address and a subhome address of the mobile terminal that are used in a subnet in the destination domain network. A second registration step of registering with a subhome agent device having jurisdiction over the destination domain network ;
In the second registration step, when the mobile terminal acquires home prefix information from the subhome agent device and generates a care-of address based on the information acquired from the domain network, the subhome agent Requesting the device to register the care-of address and sub-home address of the mobile terminal;
In the first registration step, at least one of the link layers of the mobile terminal is changed from the invalid state to the valid state, and the subhome agent device is arranged in a domain network connected through the link layer in the valid state. When the subhome agent device permits registration of the care-of address and the subhome address in the second registration step, the mobile terminal uses the main home agent as the main home address and subhome address of the mobile terminal. A mobility management method registered in a device . When it is determined that the movement is between the subnets in the same domain network, the care-of address of the mobile terminal and the home address of the domain network that is in the area are registered in the home agent device of the domain network that is in the area. The movement management method according to claim 3 , further comprising a third registration step. The mobility management method according to claim 1 or 3 , wherein the mobile terminal stores in advance information related to a home agent device that is a candidate for the main home agent device. Mobility management method according to claim 1 or 3 further comprising an information acquisition step of acquiring information about the candidate to become the home agent apparatus of the main home agent apparatus the mobile terminal from the information providing server. The mobility management method according to claim 5 or 6 , wherein, in the main home agent selection step, the mobile terminal switches the main home agent device as necessary based on information on the home agent device. Wherein the main home agent selection step, from said mobile terminal in the information about the home agent apparatus, the main home agent apparatus, according to claim 5 or claim selected based on is one priority of the information 6 The mobility management method described in 1. In the main home agent selecting step, the selection of the main home agent, the number of accesses to the domain network of the mobile terminal, residence time, according to claim 1 or 3 performed based on at least one of the amount Access Packet The mobility management method described in 1. The mobility management method according to claim 1 or 3 , wherein the subhome address is generated based on the home prefix information. A main home agent device that communicates with an access point device arranged in a subnet that constitutes a domain network, and manages the location of a mobile terminal that moves between other subnets in the same domain network and between domain networks of different service forms A main home agent selector for selecting
A network for determining whether the mobile terminal is moving between the subnets in the same domain network or moving between domain networks having different service forms, depending on whether or not the link layer or communication medium used by the mobile terminal is changed A layer communication processing unit;
A home agent registration unit that registers a main home address and a subhome address of the mobile terminal in the main home agent device when it is determined that the mobile network has moved between different domain networks ;
The home agent registration unit is arranged in a domain network connected through a link layer in which at least one of the link layers of the mobile terminal has an invalid state from an invalid state, and the sub home agent device is in the valid state, A mobile terminal that registers a main home address and a subhome address of the mobile terminal in the main home agent device when the mobile terminal acquires home prefix information . Recognizing that the home prefix acquired in the moved domain network is different from the home prefix acquired in the source domain network, a confirmation unit is provided to confirm that the movement is between domain networks of different service types. The mobile terminal according to claim 11 , further comprising: A main home agent device that communicates with an access point device arranged in a subnet that constitutes a domain network, and manages the location of a mobile terminal that moves between other subnets in the same domain network and between domain networks of different service forms A main home agent selector for selecting
A network for determining whether the mobile terminal is moving between the subnets in the same domain network or moving between domain networks having different service forms, depending on whether or not the link layer or communication medium used by the mobile terminal is changed A layer communication processing unit;
A home agent registration unit for registering a main home address and a subhome address of the mobile terminal in the main home agent device when it is determined that the mobile network has moved between different domain networks;
A subhome agent that has jurisdiction over a destination domain network for a care-of address and a subhome address used in a subnet in the destination domain network when it is determined that the domain network has moved from one service network to another. A mobile IP processing unit registered in the device;
With
The mobile IP processing unit, when the mobile terminal acquires home prefix information from the subhome agent device and generates a care-of address based on the information acquired from the domain network, the subhome agent device Request registration of the care-of address and sub-home address of the mobile terminal,
The home agent registration unit is arranged in a domain network connected through the link layer in which at least one of the link layers of the mobile terminal has an invalid state from an invalid state, and the sub home agent device is in a valid state, A mobile terminal that registers a main home address and a subhome address of the mobile terminal in the main home agent device when the subhome agent device permits registration of a care-of address and a subhome address in the mobile IP processing unit . When it is determined that the movement is between the subnets in the same domain network, the care-of address of the mobile terminal and the home address of the domain network that is in the area are registered in the home agent device of the domain network that is in the area. The mobile terminal according to claim 12 , further comprising a mobile IP processing unit. The mobile terminal according to claim 11 or 13 , further comprising a home domain storage unit that stores in advance information related to a home agent device that is a candidate for the main home agent device. The mobile terminal according to claim 11 or 13 , wherein the main home agent selection unit further acquires information on home agent devices that are candidates for the main home agent device from an information providing server. The mobile terminal according to claim 15 or 16 , wherein the main home agent selection unit further switches the main home agent device as necessary based on information on the home agent device. The main home agent selecting section further from the information relating to the home agent apparatus, the main home agent apparatus, according to claim 15 or claim 16 selected based on is one priority of the information Mobile terminal. The main home agent selecting section, the main home agent selection, the number of accesses to the domain network of the mobile terminal, residence time, according to claim 11 or 13 carried out based on at least one of the amount Access Packet The mobile terminal according to. The mobile terminal according to claim 11 or 13 , wherein the subhome address is generated based on the home prefix information.

Images