JP4677803B2 - Movement management method of ad hoc router in ad hoc network - Google Patents

Description

  The present invention relates to a system for accommodating an ad hoc network in a mobile network, and more particularly, to an ad hoc router mobility management method capable of reducing the processing load of terminals constituting an ad hoc network in handover between ad hoc routers.

There is an IETF Network Mobility (Nemo) described in Non-Patent Document 1 as a prior art. Nemo is Mobile IPv6 technology that has been improved to support network mobility. There are two components: a Mobile Router (MR) located at the boundary between a movable network and its upper network, and a Home Agent (HA) that manages the MR. When the MR moves under a subnet that has a different prefix from the home network, the Home Address (HoA) that is used in the home network and the Care-of Address (CoA) that is used in the visited network are displayed. In addition to the relationship, the correspondence between the MR HoA and the subnet prefix managed by the MR is also registered with the HA. A prefix is a part of an IP address in IPv6 and is a part indicating an address attribute. Even if the MR moves in this way, only the correspondence between the MR's HoA and CoA changes, and the correspondence between the MR's HoA and the subnet managed by the MR does not change. The terminal that does not have to detect the movement of the network has an excellent characteristic.
Vijay Devarapalli et al., "Network Mobility (NEMO) Basic Support Protocol", [on-line], IETF, [searched November 29, 2004], Internet <http://www.mobilenetworks.org/nemo/drafts/draft -ietf-nemo-basic-support-03.txt>

  However, in an ad hoc network in which terminals dynamically configure a network and all terminals belonging to the network perform the role of a router, a plurality of MRs exist in the ad hoc network. Considering the case where the MR itself connected to the higher level network switches as the ad hoc network moves, when a handover occurs where the MR in the ad hoc network switches, the prefix in the ad hoc network changes. Therefore, not only MR change processing, but all terminals in the ad hoc network must perform handover processing (if all MRs existing in the ad hoc network have the same prefix, only the MR Handover processing may be possible, but that assumption is not realistic). The hand-over process of the terminal in the ad hoc network described here is a process of notifying the Home Agent of the correspondence between HoA and the new CoA if the terminal is a communication terminal that supports Mobile IP. If it is a fixed terminal that does not support mobility, this means processing such as notifying the communication partner of the change of the IP address in order to continue the session.

Patent Document 1 describes a method for accommodating an ad hoc network in a fixed network having a mobility control function. However, switching of an ad hoc router in the ad hoc network is not considered.
JP 2004-80642 A

  The problem in these prior arts is that not only the ad hoc router but also all the terminals constituting the ad hoc network must perform the handover process at the time of handover when the ad hoc router is switched. The reason is that the ad hoc router has a unique prefix.

  The present invention has been made in view of such a situation, and in order to solve the above problem, an ad hoc router capable of performing handover between ad hoc routers without being aware of handover by a terminal in the ad hoc network. It is an object of the present invention to provide a mobility management method and an ad hoc network accommodation system that realizes the method.

In order to solve the above problems, the present invention has the following configuration.
Summary of the Invention in a first aspect, the assignment means for assigning a prefix to the ad hoc network, a management unit for managing a prefix list correspondence between the address of the prefix and ad hoc router assigned by該割those means, the ad hoc network Transfer means for transferring packets addressed to the assigned prefix to the ad hoc router based on the prefix list, and changing the address of the prefix list from the old ad hoc router to the address of the new ad hoc router at the time of handover to switch the ad hoc router The present invention resides in an ad hoc router mobility management method in an ad hoc network characterized by comprising a change means .
The gist of the invention described in claim 2 is that the management means further manages the correspondence relation with the address of the home agent as the prefix list, and the movement management method of the ad hoc router in the ad hoc network according to claim 1 Exist.
The gist of the invention described in claim 3 is that the managing means further manages the correspondence relationship of the ad hoc network with the access method to the mobile network as the prefix list. It exists in the movement management method of the ad hoc router in a network.
The gist of the invention described in claim 4 is that a handover request is transmitted from the old ad hoc router to the new ad hoc router at the time of handover to switch the ad hoc router, and the handover request is sent from the new ad hoc router to the management means. The method of managing movement of an ad hoc router in an ad hoc network according to any one of claims 1 to 3, wherein:
The gist of the invention described in claim 5 resides in an ad hoc router mobility management program for realizing the ad hoc router mobility management method in the ad hoc network according to any one of claims 1 to 4 .
The gist of the invention described in claim 6 resides in a recording medium on which the ad hoc router mobility management program described in claim 5 is recorded .
The gist of the invention described in claim 7 is that it is connectable to both an ad hoc network and a mobile network, a routing function to a terminal in the ad hoc network, an ad hoc network registration function to a prefix management server, and a handover notification function described later. An ad hoc router having a function of assigning a prefix to the ad hoc network in response to an ad hoc network registration request from the ad hoc router, and a correspondence list between the address of the ad hoc router and the prefix And the address of the prefix list is changed from the old ad hoc router to the new ad hoc router address at the time of handover to switch the ad hoc router. A prefix management server having a function of changing and a function of setting a packet transfer to the ad hoc network; and a user management packet that is present in the mobile network and captures a user packet addressed to the ad hoc network based on the prefix list. And an ad hoc network accommodation system having a packet transfer server having a transfer function .
The gist of the invention described in claim 8 is a function that is present in a mobile network and assigns a prefix to the ad hoc network in response to an ad hoc network registration request from an ad hoc router, and the correspondence between the address of the ad hoc router and the prefix. A function to manage as a list, a function to change the address of the prefix list from the old ad hoc router to the address of the new ad hoc router at the time of handover to switch the ad hoc router, and a function to set the packet forwarding to the ad hoc network It exists in the prefix management server which comprises.

  ADVANTAGE OF THE INVENTION According to this invention, the hand-over between ad hoc routers can be performed without being conscious of the terminal which comprises an ad hoc network. The reason for this is to manage the correspondence between the prefixes of the ad hoc network and the ad hoc routers. This is because they can be switched.

  FIG. 1 shows a configuration diagram of a first embodiment of the present invention. FIG. 1 shows a state in which the ad hoc network 10 is connected to the mobile network 40. The mobile routers 11 and 12 and the communication terminals 13 and 14 as an example of an ad hoc router use a routing protocol as discussed in MANET (MANET: Mobile Ad-hoc NET works) of the IETF (The Internet Engineering Task Force). Thus, an ad hoc network 10 is formed. The mobile routers 11 and 12 are ad hoc routers that exist at the boundary between the ad hoc network 10 and the mobile network 40 and have an interface that can be connected to the ad hoc network 10 and the mobile network 40. An ad hoc network registration function to the management function 20 and a handover notification function are provided. In this embodiment, a mobile router is used as an example of an ad hoc router. However, it is not essential that the ad hoc router supports mobility, but an arbitrary matter. The communication terminals 13 and 14 are terminals existing in the ad hoc network 10 and are connected to the mobile network 40 via the mobile routers 11 and 12. The prefix management function 20 is a function existing in the mobile network 40, a function for assigning a prefix to the ad hoc network 10 in response to a registration request from the mobile routers 11 and 12, a function for managing the correspondence between the mobile router and the prefix, and a packet The transfer function 30 has a function of setting packet transfer to the ad hoc network 10. The packet transfer function 30 exists in the mobile network 40 and has a function of capturing and transferring a user packet addressed to the ad hoc network 10 based on an instruction from the prefix management function 20.

  FIG. 2 shows a sequence when registering the ad hoc network 10. The mobile routers 11 and 12 and the communication terminals 13 and 14 which are ad hoc routers construct the ad hoc network 10 using the routing protocol discussed in MANET. The mobile router 11 connected to the mobile network 40 in the ad hoc network 10 transmits an ad hoc network registration request to the prefix management function 20 triggered by the construction of the ad hoc network 10. The ad hoc network registration request includes the IP address of the mobile router 11 attached to the interface connected to the mobile network 40. When receiving the ad hoc network registration request, the prefix management function 20 assigns a prefix to be used in the ad hoc network 10 to the IP address of the mobile router 11 and responds with the prefix assigned to the ad hoc network registration response. Here, the prefix assigned to the ad hoc network 10 is transferred to the packet transfer function 30 by routing in the mobile network 40. When receiving the ad hoc network registration response, the mobile router 11 registers the prefix included in the message and transmits an ad hoc network registration confirmation message to the prefix management function 20. Thereafter, the prefix is notified to all terminals existing in the ad hoc network 10. When the prefix management function 20 receives the ad hoc network registration confirmation message, it creates a prefix list that describes the correspondence between the IP address of the mobile router 11 and the prefix, and transmits a transfer setting request to the packet transfer function 30. The transfer setting request includes the correspondence between the IP address of the mobile router 11 indicating the packet transfer rule and the prefix. When the packet transfer function 30 receives the transfer setting request, the packet transfer function 30 returns a transfer setting response to the prefix management function 20 when the transfer path is set based on the instruction included in the message.

FIG. 3 shows a handover sequence between ad hoc routers. Here, a procedure for performing a handover from the mobile router 11 to the mobile router 12 is shown.
First, a mobile router (MR) list creation procedure, which is a process before handover, is shown. The mobile router 11 periodically transmits an MR inquiry to all terminals in the ad hoc network 10 in order to grasp the mobile router connected to the mobile network 40 in the ad hoc network 10. The mobile router (in this case, the mobile router 12) that has received the MR inquiry returns an MR response to the mobile router 11. The mobile router 11 creates an MR list in which the IP addresses of the mobile routers connected to the mobile network 40 are registered from the received MR response.
Next, the handover procedure between ad hoc routers is shown. When the mobile router 11 detects that the link to the mobile network 40 is broken, it selects one mobile router (here, the mobile router 12) from the MR list, and the link to the mobile network 40 is still established. Send a network (NW) connection confirmation request. The mobile router 12 transmits an NW connection confirmation response notifying that the link to the mobile network 40 is established to the mobile router 11. When the mobile router 11 confirms that the link of the mobile router 12 is established, the mobile router 11 sends a handover (HO) request request to the mobile router 12 with the prefix registered in the prefix management function 20 by the mobile router 11. Send. When receiving the HO request request, the mobile router 12 transmits the HO request with the prefix received from the mobile router 11 to the prefix management function 20. Upon receiving the HO request, the prefix management function 20 changes the IP address of the mobile router corresponding to the prefix registered in the prefix list from the mobile router 11 to the mobile router 12, and then transmits a transfer setting request to the packet transfer function 30. Then, the transfer destination of the prefix packet to be handed over is changed from the mobile router 11 to the mobile router 12. Thereafter, an HO response is transmitted to the mobile router 12. When the mobile router 11 receives the HO request response, the mobile router 11 performs forwarding setting for transferring the packet from the ad hoc network 10 to the mobile network 40 to the mobile router 12. Finally, routing settings such as changing the default router of the terminal in the ad hoc network 10 from the mobile router 11 to the mobile router 12 are performed.

  Next, a second embodiment of the present invention will be described in detail with reference to the drawings. FIG. 4 shows a configuration diagram of the second embodiment of the present invention. FIG. 4 shows a state where the ad hoc network 10 is connected to the mobile network 40. The mobile routers 11 and 12 that are ad hoc routers are managed by the home agent function 50 using the Nemo protocol. Further, the prefix management function 20 has a function of setting the packet transfer to the ad hoc network 10 in the home agent function 50 in addition to the functions mentioned in the first embodiment. The home agent function 50 has a function of transmitting a prefix list change request to the prefix management function 20 at the time of handover between mobile routers in addition to the function defined by Nemo.

  FIG. 5 shows a sequence at the time of registration of the ad hoc network 10 in the second embodiment. The mobile router 11 connected to the mobile network 40 in the ad hoc network 10 transmits an ad hoc network registration request to the prefix management function 20 triggered by the construction of the ad hoc network 10. The ad hoc network registration request includes the home address of the mobile router 11 attached to the interface connected to the mobile network 40 and the address of the home agent function 50 that performs mobility management of the mobile router 11. When receiving the ad hoc network registration request, the prefix management function 20 assigns a prefix to be used in the ad hoc network 10 to the home address of the mobile router 11, and responds with the prefix assigned to the ad hoc network registration response. Here, the prefix assigned to the ad hoc network 10 is transferred to the home agent function 50 by routing in the mobile network 40. When receiving the ad hoc network registration response, the mobile router 11 registers the prefix included in the message and transmits an ad hoc network registration confirmation message to the prefix management function 20. Thereafter, the prefix is notified to all terminals existing in the ad hoc network 10. Upon receiving the ad hoc network registration confirmation message, the prefix management function 20 creates a prefix list that describes the correspondence between the home address of the mobile router 11 and the prefix and the address of the home agent function, and registers the prefix with the home agent function 50. As a request, the prefix information corresponding to the home address of the mobile router 11 is transmitted. When the home agent function 50 registers the prefix and sets the packet transfer, the home agent function 50 returns a prefix confirmation response to the prefix management function 20.

  FIG. 6 shows a handover sequence between ad hoc routers in the second embodiment. Here, a procedure for performing a handover from the mobile router 11 to the mobile router 12 is shown. The procedure until the mobile router 12 receives the handover request request is the same as that in the first embodiment. Upon receiving the handover request request, the mobile router 12 transmits the HoA and prefix of the mobile router 12 as a handover request to the home agent function 50. When the home agent function 50 receives the handover request and recognizes that it is a change request of the mobile router corresponding to the prefix, the home agent function 50 transmits the prefix change request to the prefix management function 20. When the prefix management function 20 receives the prefix change request, the prefix management function 20 updates the mobile router corresponding to the prefix from the mobile router 11 to the mobile router 12, and returns a prefix change response to the home agent function 50. Thereafter, the home agent function 50 changes the transfer path setting of the corresponding prefix and returns a handover response.

  By coordinating the prefix management function 20 and the home agent function 50, there is an effect of reducing the encapsulation overhead and the redundant route that transmits in the mobile network 40 compared to the case where the home agent function 50 is added to the first embodiment. can get.

  Next, a third embodiment of the present invention will be described in detail with reference to the drawings. A feature of the third embodiment of the present invention is that an access method connecting a mobile network to an ad hoc router can be notified to a terminal in the ad hoc network. The configuration diagram of the third embodiment of the present invention, the ad hoc network registration procedure, and the inter-ad hoc router handover procedure are the same as in FIGS. First, an ad hoc network registration procedure according to the third embodiment will be described. The mobile router 11, which is an ad hoc router, adds to the ad hoc network registration request sent to the prefix management function 20 not only the IP address of the mobile router 11 but also an access identifier for identifying the access method connected to the mobile network 40 as information. When receiving the ad hoc network registration request, the prefix management function 20 assigns a prefix to the set of the IP address and access identifier of the mobile router 11 and manages the set of the IP address, access identifier and prefix of the mobile router as a prefix list. When the mobile router 11 is assigned a prefix, the mobile router 11 notifies the ad hoc network 10 of the corresponding access identifier together with the prefix. Other registration procedures are the same as those in the first embodiment. Next, an ad hoc network registration procedure according to the third embodiment will be described. Here, a procedure for performing a handover from the mobile router 11 to the mobile router 12 will be described. First, a mobile router (MR) list creation procedure, which is a process before handover, is shown. The mobile router 11 periodically transmits an MR inquiry to all terminals in the ad hoc network 10 in order to grasp the mobile router connected to the mobile network 40 in the ad hoc network 10. The mobile router (in this case, the mobile router 12) that has received the MR inquiry returns a set of the mobile router's IP address and access identifier to the mobile router 11 as an MR response. The mobile router 11 creates an MR list in which a combination of the IP address and access identifier of the mobile router connected to the mobile network 40 is registered from the received MR response. Next, the handover procedure between mobile routers is shown. When the mobile router 11 detects that the link to the mobile network 40 is broken, the mobile router 11 selects one mobile router (in this case, the mobile router 12) having the same access identifier from the MR list, and the mobile router 40 continues to the mobile network 40. A network (NW) connection confirmation request is transmitted to confirm whether the link is established. The mobile router 12 transmits an NW connection confirmation response notifying that the link to the mobile network 40 is established to the mobile router 11. When the mobile router 11 confirms that the link of the mobile router 12 is established, the mobile router 11 sends a HO request request with the prefix registered in the prefix management function 20 to the mobile router 12. The subsequent handover procedure is the same as in the first embodiment.

  By assigning a prefix for each set of IP address and access method of the mobile router, the communication terminal in the ad hoc network 10 selects the access method to the mobile network according to the communication characteristics of the application such as communication time and bandwidth used. The effect that communication can be performed is obtained.

  As described above, the ad hoc network accommodating system of the present invention includes means for assigning a prefix to the ad hoc network, means for managing a correspondence between the prefix assigned to the ad hoc network and the mobile router, and a packet addressed to the prefix of the ad hoc network. And a function to transfer up to. The object of the present invention can be achieved by adopting such a configuration and giving a degree of freedom to the correspondence between the terminals constituting the ad hoc network and the prefix.

  Next, the operation of the first embodiment for carrying out the present invention will be described using a specific embodiment. Such an example corresponds to the first embodiment of the present invention. FIG. 7 shows a configuration diagram of the first embodiment. FIG. 7 shows a state in which the ad hoc network 10 is connected to the mobile network 40. The mobile routers 11 and 12 and the communication terminals 13 and 14 form an ad hoc network 10 using a routing protocol as discussed in MANET of IETF. The mobile routers 11 and 12 are routers that exist at the boundary between the ad hoc network 10 and the mobile network 40 and have an interface that can be connected to the ad hoc network 10 and the mobile network 40 together with the Nemo protocol. It has a routing function, an ad hoc network registration function to the prefix management server 120, and a handover notification function. The communication terminals 13 and 14 exist in the ad hoc network 10 and are terminals equipped with the Mobile IPv6 protocol, and are connected to the mobile network 40 via the mobile routers 11 and 12. The prefix management server 120 is a server existing in the mobile network 40, a function for assigning a prefix to the ad hoc network 10 in response to a registration request from the mobile routers 11, 12, a function for managing the correspondence relationship between the HoA and the prefix of the mobile router, and The packet transfer server 130 has a function of setting packet transfer to the ad hoc network 10. The packet transfer server 130 is a server existing in the mobile network 40 and has a function of capturing and transferring a user packet addressed to the ad hoc network 10 based on an instruction from the prefix management server 120. Home agents (mobile routers) 151 and 152 use the Nemo protocol to manage mobility of the mobile routers 11 and 12, respectively. Home agents (communication terminals) 153 use the Mobile IPv6 protocol to communicate with the communication terminals 13 and 14, respectively. Manage mobility.

  FIG. 8 shows a sequence when registering the ad hoc network 10. The mobile routers 11 and 12 and the communication terminals 13 and 14 which are ad hoc routers construct the ad hoc network 10 using the routing protocol discussed in MANET. The mobile router 11, which is an ad hoc router connected to the mobile network 40 in the ad hoc network 10, sends an ad hoc network registration request to the prefix management server 120 using the home agent (mobile router) 151 as a trigger when the ad hoc network 10 is constructed. Send. The ad hoc network registration request includes the HoA of the mobile router 11 attached to the interface connected to the mobile network 40. When the prefix management server 120 receives the ad hoc network registration request, the prefix management server 120 assigns the prefix used in the ad hoc network 10 to the HoA of the mobile router 11 and adds the prefix assigned to the ad hoc network registration response to the home agent (mobile router) 151. To respond through. When receiving the ad hoc network registration response, the mobile router 11 registers the prefix included in the message, and transmits an ad hoc network registration confirmation message to the prefix management server 120 via the home agent (mobile router) 151. Thereafter, the prefix is notified to all terminals existing in the ad hoc network 10. Upon receiving the ad hoc network registration confirmation message, the prefix management server 120 creates a prefix list that describes the correspondence between the HoA of the mobile router 11 and the prefix, and transmits a transfer setting request to the packet transfer server 130. The transfer setting request includes the correspondence between the HoA of the mobile router 11 and the prefix indicating the packet transfer rule. When the packet transfer server 130 receives the transfer setting request, the packet transfer server 130 returns a transfer setting response to the prefix management server 120 when the transfer path is set based on the instruction included in the message.

  FIG. 9 shows a handover sequence between ad hoc routers. Here, a procedure for performing a handover from the mobile router 11 to the mobile router 12 while the communication terminal 13 is communicating with the communication partner terminal 160 is shown. First, a mobile router (MR) list creation procedure, which is a process before handover, is shown. The mobile router 11 periodically transmits an MR inquiry to all terminals in the ad hoc network 10 in order to grasp the mobile router connected to the mobile network 40 in the ad hoc network 10. The mobile router (in this case, the mobile router 12) that has received the MR inquiry returns an MR response to the mobile router 11. The mobile router 11 creates an MR list registered by the HoA of the mobile router connected to the mobile network 40 from the received MR response.

  When the communication terminal 13 is communicating with the communication partner terminal 160 via the mobile router 11 before the handover, a packet sent from the communication partner terminal 160 to the communication terminal 13 is transmitted via the home agent (communication terminal) 153. After that, the packet transfer server 130 captures and performs IP in IP encapsulation using the packet transfer server 130 as the source address and the HoA of the mobile router 11 as the destination address according to the set transfer rules, and the home agent (mobile Router) 151. The home agent 151 performs IP in IP encapsulation using the home agent 151 as the transmission source address and the CoA of the mobile router 11 as the destination address according to the set transfer rule, and transfers the packet to the mobile router 11. When receiving the packet, the mobile router 11 performs decapsulation and transfers the packet to the communication terminal 13.

  Next, the handover procedure between ad hoc routers is shown. When the mobile router 11 detects that the link to the mobile network 40 is broken, it selects one mobile router (here, the mobile router 12) from the MR list, and the link to the mobile network 40 is still established. Send a network (NW) connection confirmation request. The mobile router 12 transmits an NW connection confirmation response notifying that the link to the mobile network 40 is established to the mobile router 11. When the mobile router 11 confirms that the link of the mobile router 12 has been established, the mobile router 11 sends a HO request request with the prefix registered in the prefix management server 120 to the mobile router 12. Upon receiving the HO request, the mobile router 12 transmits the HO request with the prefix received from the mobile router 11 to the prefix management server 120 via the home agent (mobile router) 152. Upon receiving the HO request, the prefix management server 120 changes the HoA of the mobile router corresponding to the prefix registered in the prefix list from the mobile router 11 to the mobile router 12, and then transmits a transfer setting request to the packet transfer server 130. Thus, the transfer destination of the prefix packet to be handed over is changed from the HoA of the mobile router 11 to the HoA of the mobile router 12. Thereafter, an HO response is transmitted to the mobile router 12 via the home agent (mobile router) 152. When the mobile router 11 receives the HO request response, the mobile router 11 performs forwarding setting for transferring the packet from the ad hoc network 10 to the mobile network 40 to the mobile router 12. Finally, routing settings such as changing the default router of the terminal in the ad hoc network 10 from the mobile router 11 to the mobile router 12 are performed.

When the communication terminal 13 is communicating with the communication partner terminal 160 via the mobile router 12 after the handover, a packet sent from the communication partner terminal 160 to the communication terminal 13 is transmitted via the home agent (communication terminal) 153. The packet transfer server 130 later captures and performs IP in IP encapsulation using the packet transfer server 130 as the source address and the HoA of the mobile router 12 as the destination address according to the set transfer rules, and the home agent (mobile router ) 152. The home agent (mobile router) 152 performs IP in IP encapsulation using the home agent (mobile router) 152 as the source address and the CoA of the mobile router 12 as the destination address in accordance with the set transfer rules. Forward to.
When receiving the packet, the mobile router 12 performs decapsulation and transfers the packet to the communication terminal 13.

  Next, the operation of the second embodiment for carrying out the present invention will be described. Such an example corresponds to the second embodiment of the present invention. FIG. 10 shows a configuration diagram of an embodiment of the second embodiment. FIG. 10 shows a state where the ad hoc network 10 is connected to the mobile network 40. Mobile routers 11 and 12 that are ad hoc routers are managed by a home agent (mobile router) 150 using the Nemo protocol. In addition to the functions described in the first embodiment, the prefix management server 120 has a function of setting a packet transfer to the ad hoc network 10 in the home agent (mobile router) 150. The home agent (mobile router) 150 has a function of transmitting a prefix list change request to the prefix management server 120 at the time of handover between mobile routers in addition to the function defined by Nemo.

  FIG. 11 shows a sequence at the time of registration of the ad hoc network 10 according to the second embodiment. The mobile router 11, which is an ad hoc router connected to the mobile network 40 in the ad hoc network 10, transmits an ad hoc network registration request to the prefix management server 120 triggered by the construction of the ad hoc network 10. The ad hoc network registration request includes the home address of the mobile router 11 attached to the interface connected to the mobile network 40 and the address of the home agent (mobile router) 150 that manages the movement of the mobile router 11. . When receiving the ad hoc network registration request, the prefix management server 120 assigns a prefix to be used in the ad hoc network 10 to the home address of the mobile router 11, and responds with the prefix assigned to the ad hoc network registration response. When the mobile router 11 receives the ad hoc network registration response, the mobile router 11 registers the prefix included in the message and transmits an ad hoc network registration confirmation message to the prefix management server 120. Thereafter, the prefix is notified to all terminals existing in the ad hoc network 10. When the prefix management server 120 receives the ad hoc network registration confirmation message, it creates a prefix list that describes the correspondence between the home address of the mobile router 11 and the prefix and the address of the home agent, and the home agent (mobile router) 150 The prefix information corresponding to the home address of the mobile router 11 is transmitted as a prefix registration request. When the home agent 150 (mobile router) registers the prefix and performs packet transfer setting, the home agent 150 (mobile router) returns a prefix confirmation response to the prefix management server 120.

  FIG. 12 shows a handover sequence between ad hoc routers according to the second embodiment. Here, a procedure for performing a handover from the mobile router 11 to the mobile router 12 is shown. The procedure until the mobile router 12 receives the handover request request is the same as that in the first embodiment. Upon receiving the handover request request, the mobile router 12 transmits a Binding Update including the HoA and prefix of the mobile router as a handover request to the home agent (mobile router) 150. When the home agent (mobile router) 150 receives the Binding Update and recognizes that it is a change request for the mobile router corresponding to the prefix, the home agent (mobile router) 150 transmits the prefix change request to the prefix management server 120. Upon receiving the prefix change request, the prefix management server 120 updates the prefix list and returns a prefix change response to the home agent (mobile router) 150. Thereafter, the home agent (mobile router) 150 changes the transfer path setting of the corresponding prefix, and returns a Binding Acknowledgment that is a handover response.

  Next, a third embodiment for carrying out the present invention will be described in detail with reference to the drawings. A feature of the third embodiment is that it is possible to notify a terminal in the ad hoc network of an access method connecting between the mobile network and the ad hoc router. The configuration diagram of the third embodiment of the present invention, the ad hoc network registration procedure, and the inter-ad hoc inter-router handover procedure are the same as in FIG. First, an ad hoc network registration procedure according to the third embodiment will be described. The mobile router 11, which is an ad hoc router, adds not only the IP address of the mobile router 11 but also an access identifier for identifying the access method connected to the mobile network 40 as information to the ad hoc network registration request sent to the prefix management server 120. When the prefix management server 120 receives the ad hoc network registration request, the prefix management server 120 assigns a prefix to the set of the IP address and access identifier of the mobile router 11 and manages the set of the IP address, access identifier and prefix of the mobile router as a prefix list. When the mobile router 11 is assigned a prefix, the mobile router 11 notifies the ad hoc network 10 of the corresponding access identifier together with the prefix. Other registration procedures are the same as those in the first embodiment. Next, an ad hoc network registration procedure according to the third embodiment will be described. Here, a procedure for performing a handover from the mobile router 11 to the mobile router 12 will be described. First, a mobile router (MR) list creation procedure, which is a process before handover, is shown. The mobile router 11 periodically transmits an MR inquiry to all terminals in the ad hoc network 10 in order to grasp the mobile router connected to the mobile network 40 in the ad hoc network 10. The mobile router (in this case, the mobile router 12) that has received the MR inquiry returns a set of the mobile router's IP address and access identifier to the mobile router 11 as an MR response. The mobile router 11 creates an MR list in which a combination of the IP address and access identifier of the mobile router connected to the mobile network 40 is registered from the received MR response. Next, the handover procedure between mobile routers is shown. When the mobile router 11 detects that the link to the mobile network 40 is broken, the mobile router 11 selects one mobile router (in this case, the mobile router 12) having the same access identifier from the MR list, and the mobile router 40 continues to the mobile network 40. A network (NW) connection confirmation request is transmitted to confirm whether the link is established. The mobile router 12 transmits an NW connection confirmation response notifying that the link to the mobile network 40 is established to the mobile router 11. When the mobile router 11 confirms that the link of the mobile router 12 has been established, the mobile router 11 sends a HO request request with the prefix registered in the prefix management server 120 to the mobile router 12. The subsequent handover procedure is the same as in the first embodiment.

  INDUSTRIAL APPLICABILITY According to the present invention, the present invention can be applied to applications such as providing a personal area network accommodation service for users of mobile carrier operators.

It is a block diagram which shows the structure of 1st Embodiment. It is a flowchart which shows the operation | movement at the time of ad hoc network registration of 1st Embodiment. It is a flowchart which shows the operation | movement of the hand-over between the ad hoc routers of 1st Embodiment. It is a block diagram which shows the structure of 2nd Embodiment. It is a flowchart which shows the operation | movement at the time of ad hoc network registration of 2nd Embodiment. It is a flowchart which shows the operation | movement of the handover between the ad hoc routers of 2nd Embodiment. 1 is a block diagram illustrating a configuration of Example 1. FIG. 3 is a flowchart illustrating an operation during ad hoc network registration according to the first exemplary embodiment. 4 is a flowchart illustrating a handover operation between ad hoc routers according to the first exemplary embodiment. 6 is a block diagram illustrating a configuration of Example 2. FIG. 6 is a flowchart illustrating an operation when registering an ad hoc network according to the second exemplary embodiment. 6 is a flowchart illustrating a handover operation between ad hoc routers according to the second exemplary embodiment.

Explanation of symbols

10 Ad hoc network 11, 12 Mobile router (ad hoc router)
13, 14 Communication terminal 20 Prefix management function 30 Packet transfer function 40 Mobile network 50 Home agent function 120 Prefix management server 130 Packet transfer server 150-152 Home agent (mobile router)
153 Home agent (communication terminal)
160 Communication partner terminal

Claims (8)

An assigning means for assigning a prefix to an ad hoc network;
Management means for managing the correspondence between the prefix assigned by the assigning means and the address of the ad hoc router as a prefix list ;
Transfer means for transferring a packet addressed to the prefix assigned to the adhoc network to the adhoc router based on the prefix list,
An ad hoc router mobility management method in an ad hoc network, comprising: changing means for changing an address of the prefix list from an old ad hoc router to an address of a new ad hoc router at the time of handover for switching the ad hoc router. The ad hoc router mobility management method in an ad hoc network according to claim 1, wherein the management means further manages a correspondence relationship with a home agent address as the prefix list . The ad hoc router mobility management method according to claim 1 or 2, wherein the management unit further manages a correspondence relationship of the ad hoc network with a mobile network access method as the prefix list . The handover request is transmitted from the old ad hoc router to the new ad hoc router at the time of handover to switch the ad hoc router, and the handover request is transmitted from the new ad hoc router to the management means. The ad hoc router mobility management method in the ad hoc network according to any one of 1 to 3 . An ad hoc router movement management program for realizing the ad hoc router movement management method in the ad hoc network according to any one of claims 1 to 4 .   The recording medium which recorded the ad hoc router movement management program of Claim 5. An ad hoc router that is connectable to both an ad hoc network and a mobile network, and has a routing function to a terminal in the ad hoc network, an ad hoc network registration function to a prefix management server, and a handover notification function;
  A function that exists in the mobile network and assigns a prefix to the ad hoc network in response to an ad hoc network registration request from the ad hoc router; a function that manages a correspondence between the address of the ad hoc router and a prefix as a prefix list; A prefix management server having a function of changing an address of a prefix list from an old ad hoc router to an address of a new ad hoc router at the time of handover for switching an ad hoc router, and a function of setting packet forwarding to the ad hoc network;
  An ad hoc network accommodation system comprising: a packet transfer server that exists in the mobile network and has a function of capturing and transferring a user packet addressed to the ad hoc network based on the prefix list. A function that exists in a mobile network and allocates a prefix to the ad hoc network in response to an ad hoc network registration request from an ad hoc router; a function that manages a correspondence relationship between an address of the ad hoc router and a prefix as a prefix list; and the ad hoc router A prefix management server having a function of changing an address of a prefix list from an old ad hoc router to an address of a new ad hoc router at the time of handover for switching, and a function of setting packet forwarding to the ad hoc network .

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