JP2009212892A - Mobile terminal and connection station device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mobile terminal, and the like, capable of preventing waste of network resources and interruption of service to an MN, since the state along a new path is yet not constructed, when a connection destination is changed due to movement. <P>SOLUTION: The mobile terminal is provided with: a receiving means for a mobile terminal 101 itself for receiving a first message for acquiring connection station information regarding a first connection station device 103 from a second connection station device 109; a message generating means for generating a second message, including connection station information regarding the first connection station device, based on the first message received; and a transmitting means for transmitting the second generated message to the second connecting station device. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a mobile terminal and a connection station apparatus that establish a signaling path between a mobile terminal and a communication terminal that is a communication partner when the connection destination of the mobile terminal is changed due to movement.

  Usually, the signaling control protocol has different operation procedures in the scene of peer discovery. This is a path-coupled signaling scheme in which data and signaling messages take the same path, for example, RSVP (Resource reSerVation Protocol: see Non-Patent Document 1) or NSIS (Next Steps In Signaling: see Non-Patent Document 2) Is particularly necessary. This is because the signaling peer at the new position (location) is usually not predefined. When applying these signaling control protocols to a MN (Mobile Node), peer discovery is initiated by a MN address change. This is used in most mobility scenarios. However, in some mobility management schemes such an arrangement does not work well.

  For example, in the scheme of Proxy MIPv6 (see Non-Patent Document 3), when the MN moves within the same LMA (Local Mobility Anchor) domain, the address is not changed. In this case, if the trigger for peer discovery is based on the MN's address change, no new peer is discovered when the MN moves between MAGs (Mobile Access Gateways). Since there is no peer change, the signaling protocol at the MN continues to send messages directly to the previous peer.

Since these messages are sent to the previous peer in a way that does not cause the intermediate node to process the message (eg C-mode signaling in NSIS, see Non-Patent Document 6), the new peer that exists between the MN and the previous peer is Not found. This results in the undesirable signaling state being maintained. Eventually, network resources are wasted because the old state is not removed, and service to the MN is interrupted because the state along the new route is not established.
R. Braden, Ed. "Resource ReSerVation Protocol (RSVP) -Version 1 Functional Specification", RFC2205, http://www.ietf.org/rfc/rfc2205.txt R. Hancock, G. Karagiannis, J. Loughney, S. Van den Bosch. "Next Steps in Signaling (NSIS): Framework", RFC4080, http://www.ietf.org/rfc/rfc4080.txt S.Gundavelli et al., "Proxy Mobile IPv6" September 5,2007, ftp://ftp.rfc-editor.org/in-notes/internet-drafts/draft-ietf-netlmm-proxymip6-03.txt T.Narten et al., "Neighbor Discovery for IP Version 6 (IPv6)", RFC2461, December 1998, http://www.ietf.org/rfc/rfc2461.txt P.Calhoun et al., "Diameter Network Access Server Application", RFC4005, August 2005, ftp://ftp.rfc-editor.org/in-notes/rfc4005.txt H. Schulzrinne et al., "GIST: General Internet Signaling Transport", draft-ietf-nsis-ntlp-15, February 2008, work in progress

  One approach to alleviating that problem is to configure the MN to send peer discovery messages at a predetermined frequency regardless of address changes. However, if the frequency is too high, the peer discovery process usually involves several handshakes, increasing the processing load on the MN and network nodes. Although some networks can impose restrictions on discovery messages, such methods cannot provide rapid peer change detection when set to a low frequency.

  The MN can also be configured to send a discovery message when a router change is known. This greatly reduces the discovery messages transmitted compared to the above scheme. However, in some cases, the MN is unaware of the router change. For example, in the case of Proxy MIPv6 and a MAG is formed with the same link local address, the MN cannot detect a change.

  Obviously, the above problem also applies to off-path signaling in certain cases. For example, if there are different signaling control entities associated with different MAGs, the MN sends a signal directly to the old control entity when connected to the new MAG. It becomes a network control problem.

  Obviously, the above problems require a better method of proper signaling management in a data communication network.

  In view of the above-described problems, the present invention causes a waste of network resources and interruption of service to the MN because a state along a new route (signaling route) is not established when the connection destination changes due to movement. Can be prevented.

  The present invention can also reduce the necessary signaling sent by the MN after handover. Thereby, the load of communication and calculation of MN can be reduced. This also helps reduce MN power consumption. Since the exchange of messages between the MN and the network access point is reduced, valuable communication resources can be saved in a wireless environment. As shown in FIG. 17, in a network in which a plurality of MNs 1703, 1705, and 1707 exist under an access point 1701, a necessary signaling message is reduced by one from each MN, so that a plurality of communication slots, particularly uplink radios The channel (time to send messages 17003, 17005, 17007) can be released. Therefore, the reduction of signaling messages is significant. This is exactly the case when considering the asymmetry of the uplink (17003, 17005, 17007) and downlink (17001) in wireless technology.

  In order to achieve the above object, according to the present invention, a mobile terminal communicates with a communication device that is a communication partner of the mobile terminal via any one of a plurality of connection station devices arranged in a predetermined domain. Signaling between the mobile terminal and the communication device via a second connection station device newly connected from the first connection station device to which the mobile terminal has been connected by movement in the communication system The mobile terminal in the communication system configured to construct a route by the second connection station device, wherein the mobile terminal itself acquires connection station information related to the first connection station device. Receiving means for receiving one message from the second connection station apparatus, and a second message including connection station information relating to the first connection station apparatus based on the received first message A message generating means for generating for, and transmission means for transmitting the generated second message to the second connection station device, the mobile terminal comprising is provided. With this configuration, when a connection destination changes due to movement, it is possible to prevent waste of network resources and interruption of service to the MN because a state along a new route (signaling route) is not established. In addition, MN signaling processing caused by movement can be reduced. The first message corresponds to an RA_Enhanced message described later, and the second message corresponds to an Msg_C_Enhanced message described later.

  In the mobile terminal of the present invention, it is a preferable aspect of the present invention that the first message includes connection station information related to the second connection station apparatus. With this configuration, it is possible to appropriately transmit the second message.

  In the mobile terminal of the present invention, it is a preferable aspect of the present invention that the proxy node performs processing of the first connection station device and / or the second connection station device. With this configuration, even when the connecting station device cannot process the signaling, the processing can be performed.

  Further, according to the present invention, in a communication system in which a mobile terminal communicates with a communication device that is a communication partner of the mobile terminal via any one of a plurality of connection station devices arranged in a predetermined domain, The mobile terminal is newly connected to establish a signaling path between the mobile terminal and the communication device through the connection station device newly connected from the connection station device before the movement that has been connected by the movement until then. If the connection station device determines that the mobile terminal has moved from the connection station device before movement that is a connection station device in the predetermined domain that was connected before movement, the connection before movement Message generating means for generating a first message for acquiring connection station information relating to a station device, transmitting means for transmitting the generated first message to the mobile terminal, and the first A message transmitted from the mobile terminal based on a message, the second message including connection station information related to the connection station device before the movement and processing request information indicating that a new signaling path construction process should be performed. Receiving means for receiving, and control means for constructing a signaling path between the mobile terminal and the communication device via the connection station device itself, wherein the message generating means Communication state information held by the connection station device before movement based on connection station information related to the connection station device and constructed so that the mobile terminal communicates with the communication device via the connection station device before movement The transmission means transmits the generated third message to the connection station apparatus before the movement, and transmits the received message to the receiver. Receives the fourth message including the communication state information transmitted from the connection station device before movement based on the third message, and the control means receives the received communication state information and the process A connection station apparatus that constructs the signaling path based on the request information is provided. With this configuration, when the connection destination changes due to movement, it is possible to prevent waste of network resources and interruption of service to the MN because a state along a new route (signaling route) is not established. The first message corresponds to an RA_Enhanced message described later, the second message corresponds to an Msg_C_Enhanced message described later, the third message corresponds to a Cxt_Req message described later, and the fourth message is a Cxt_Rsp message described later. Corresponds to a message. Further, the processing request information refers to information indicated in a “Discovery Flag” field described later. Communication state information refers to a signaling context described later.

  In the connection station apparatus of the present invention, it is a preferable aspect of the present invention that the first message includes connection station information regarding the connection station apparatus itself. With this configuration, it is possible to appropriately receive the second message.

  In the connection station apparatus of the present invention, it is a preferable aspect of the present invention that the second message includes address information of the communication apparatus. With this configuration, it is possible to construct a new signaling path between the mobile terminal and the communication device.

  Further, according to the present invention, in a communication system in which a mobile terminal communicates with a communication device that is a communication partner of the mobile terminal via any one of a plurality of connection station devices arranged in a predetermined domain, The mobile terminal is newly connected to establish a signaling path between the mobile terminal and the communication device through the connection station device newly connected from the connection station device before the movement that has been connected by the movement until then. If the connection station device determines that the mobile terminal has moved from the connection station device before movement that is a connection station device in the predetermined domain that was connected before movement, the connection before movement A message that is held in a station device and that generates a first message for acquiring communication state information that is constructed so that the mobile terminal communicates with the communication device via the connection station device before the movement Generating means, transmitting means for transmitting the generated first message to a predetermined server, and a second message including the first message transmitted from the predetermined server to the connection station apparatus before movement. Based on the third message including the communication state information transmitted from the connection station apparatus before the movement and the processing request information indicating that a new signaling path should be established from the mobile terminal. Control for performing construction of a signaling path between the mobile terminal and the communication device via the connection station device itself based on the reception means for receiving the message and the received communication state information and the processing request information A connection station apparatus comprising the means. With this configuration, when a connection destination changes due to movement, it is possible to prevent waste of network resources and interruption of service to the MN because a state along a new route (signaling route) is not established. The first message corresponds to an AA_Request message described later, the second message corresponds to an AS_Request message described later, and the third message corresponds to a Cxt_Rsp message described later. Further, the processing request information refers to information indicated in a “Discovery Flag” field described later. Communication state information refers to a signaling context described later. The predetermined server refers to an AAA entity described later.

  In the connection station apparatus of the present invention, it is a preferred aspect of the present invention that the first message includes predetermined code information agreed in advance between the predetermined server and the connection station apparatus. . With this configuration, it is not possible to respond to a message from a device for which consent has not been made, so security can be enhanced. The predetermined code information corresponds to an AVP code described later.

  In the connection station apparatus of the present invention, it is a preferable aspect of the present invention that the fourth message includes address information of the communication apparatus. With this configuration, it is possible to construct a new signaling path between the mobile terminal and the communication device.

  Further, according to the present invention, in a communication system in which a mobile terminal communicates with a communication device that is a communication partner of the mobile terminal via any one of a plurality of connection station devices arranged in a predetermined domain, The mobile terminal is newly connected to establish a signaling path between the mobile terminal and the communication device through the connection station device newly connected from the connection station device before the movement that has been connected by the movement until then. If the connection station device determines that the mobile terminal has moved from the connection station device before movement that is a connection station device in the predetermined domain that was connected before movement, the connection before movement Message generating means for generating a first message including information indicating a request for acquisition of connection station information related to a station device, and before the generated first message is placed in the predetermined domain Transmission means for transmitting to a management device or a predetermined server for managing a plurality of connection station devices, and a connection relating to the connection station device before movement transmitted from the management device or the predetermined server based on the first message A receiving means for receiving a second message including station information and a message including processing request information indicating that a new signaling path construction process transmitted from the mobile terminal should be performed, and via the connecting station device itself Control means for constructing a signaling path between the mobile terminal and the communication device, and the message generation means is configured to receive the pre-movement based on the received connection station information regarding the connection station apparatus before the movement. Communication state information constructed so that the mobile terminal communicates with the communication device via the connection station device before moving. A third message to be transmitted, the transmission means transmits the generated third message to the connection station apparatus before movement, and the reception means is configured to transmit the third message based on the third message. The control means receives the fourth message including the communication state information transmitted from the connection station device before movement, and the control means constructs the signaling path based on the received communication state information and the processing request information. A connecting station device is provided. With this configuration, when the connection destination changes due to movement, it is possible to prevent waste of network resources and interruption of service to the MN because a state along a new route (signaling route) is not established. The first message corresponds to a PBU message or AA_Request message described later, the second message corresponds to a PBA message or AA_Answer message described later, the third message corresponds to a Cxt_Req message described later, and the fourth message The message corresponds to a Cxt_Rsp message described later. Further, the processing request information refers to information indicated in a “Discovery Flag” field described later. Communication state information refers to a signaling context described later. The management device refers to an LMA described later, and the predetermined server refers to an AAA entity described later.

  In the connection station apparatus of the present invention, when the receiving means does not receive the processing request information from the mobile terminal, the control means transmits a signaling transmitted from the mobile terminal to the connection station apparatus before the movement. It is a preferable aspect of the present invention that when receiving by the receiving means, the signaling path is constructed based on the communication state information. With this configuration, there is no need to change the state of the constructed signaling path.

  In the connection station apparatus of the present invention, it is a preferable aspect of the present invention that the third message includes at least the identification information of the mobile terminal, the address information of the connection station apparatus itself, and the identification information of the signaling session. is there. With this configuration, it is possible to appropriately receive a message including communication state information.

  In the connection station apparatus of the present invention, it is a preferable aspect of the present invention that the communication state information includes one or more of a session ID, a security key, a port number, and an authentication token. With this configuration, a signaling path can be constructed.

  In the connection station apparatus of the present invention, it is a preferable aspect of the present invention that the proxy node performs processing of the connection station apparatus before moving and / or the connection station apparatus. With this configuration, even when the connecting station device cannot process the signaling, the processing can be performed.

  The mobile terminal and the connection station apparatus of the present invention have the above-described configuration. When the connection destination changes due to movement, network resources are not wasted and a state along a new route (signaling route) is not established. This can prevent the service from being interrupted.

<First Embodiment>
In the following description of the embodiments, the specified numerical values, times, structures, protocols, parameters, and the like are used for facilitating the understanding of the present invention, and are not limited thereto.

  An example of a network configuration in the first embodiment of the present invention is shown in FIG. An LMD (Local Mobility Domain) 100 includes MAGs managed by the LMA 105, for example, MAGs 103 and 109. For the sake of explanation, Proxy MIPv6 (hereinafter also simply referred to as PMIP) is assumed to be a protocol that operates between the LMA 105 and the MAG (MAG 103, 109). As shown in FIG. 1, the MN 101 is first connected to the MAG 103. When connected, the home network prefix (MN-HNP) is assigned to the MN 101. Thereafter, the MN 101 moves to a new location 111 and connects to the MAG 109. In PMIP, the MAG 109 notifies the same MN-HNP to the MN 101 that has moved to the new location 111. Therefore, the MN 101 can maintain the same address when moving from the MAG 103 to the MAG 109.

  FIG. 2 is a sequence chart showing an example of a processing sequence when the MN according to the first embodiment of the present invention first joins the LMD. As shown in FIG. 2, the MN 101 connects to the MAG 103 by executing an access technology specific procedure (step S2001). This includes, for example, authentication and association in the case of an IEEE 802.11 access network. Therefore, in step S2001, other nodes such as an AAA (Authentication, Authorization, and Accounting) server and a proxy (not shown) are also included in the network.

  With the connection in step S2001, the MAG 103 executes the PMIP process (step S2003). This includes, for example, transmitting a PBU (Proxy Binding Update) message to the LMA 105, receiving a PBA (Proxy Binding Acknowledgment) message from the LMA 105, and constructing a corresponding tunnel. MAG 103 is informed of the MN-HNP assigned in the process.

  In the above procedure, the MAG 103 is informed whether the MN 101 is connected to the LMD 100 for the first time. There are two possible approaches to inform the MAG 103 of such information. The first method is through an access control process and can be indicated, for example, by the AAA server setting a special result code in the AA_Answer message. The second method is via a PBA message from the LMA 105.

  For example, if the LMA 105 receives a PBU message from the MAG 103 and there is no binding cache for the MN 101, the LMA 105 resets a special flag in the PBA message, eg, sets the last bit of the “Reserved” field to “0 (zero). ) ”. If there is a binding cache for the MN 101 when the LMA 105 receives the PBU message, the LMA 105 sets its flag to “1”.

  As illustrated in FIG. 2, the MN 101 transmits an RS (Router Solicitation) message (see Non-Patent Document 4) (step S2005). The MAG 103 transmits an RA (Router Advertisement) message (step S2007). If the network allows automatic address formation of MN 101, the RA message includes MN-HNP information. Otherwise, the RA message sets the Managed Address Configuration flag. This is to cause the MN 101 to execute DHCP_Request (step S2009) and DHCP_Reply (step S2011) of the Dynamic Host Configuration Protocol (DHCP) procedure. Thereafter, an appropriate address is formed in the MN 101 and preparation for communication is made.

  In order to support communication with the CN 107, the MN 101 needs to start Msg_Q which is resource control signaling (step S2013). An example of Msg_Q is an RSVP RESV message or an NSIS RESERVE message. Since MN 101 has a new address obtained from MN-HNP, it needs to discover a signaling peer. Assuming NSIS is used for resource control signaling, the transmission of Msg_Q involves a handshake between MN 101 and a signaling peer, eg MAG 103.

  As shown in FIG. 2, three messages are actually exchanged during the transmission of Msg_Q. Since there is no signaling state regarding the MN 101, the MAG 103 needs to transfer Msg_Q (step S2015) and continue peer discovery. The same happens with LMA 105 until signaling reaches CN 107. When the resource control signaling ends, communication between the MN 101 and the CN 107 is executed in an appropriate reservation state (step S2019).

  FIG. 3 is a sequence chart showing an example of a processing sequence when the MN according to the first embodiment of the present invention connects to the MAG 109. As in FIG. 2, the MN 101 connects to the MAG 109 using the access technology procedure (step S3001). The MAG 109 executes PMIP processing by connection (step S3003). Like the MAG 103, the MAG 109 is informed whether the MN 101 has connected to the LMD 100 for the first time. When the MN 101 moves from the MAG 103, it is not the first connection in the LMD 100.

  Therefore, when the MAG 109 receives an RS message from the MN 101 (step S3005), the MAG 109 transmits an RA_Enhanced message (step S3007). The RA_Enhanced message is a Router Advertisement message defined in Non-Patent Document 3, and the RA_Enhanced message has a Signaling_Peer option item that carries information about the signaling awareness (Aware) node associated with the MAG 109. If multiple signaling protocols are supported in the network, one or more Signaling_Peer option items are included in the RA_Enhanced message.

  For example, the RA_Enhanced message may include an option item for one RSVP and an option item for one NSIS. The Signaling_Peer option item includes, for example, information about the address of the signaling peer, a port number to be used, a transmission protocol, and encryption information if necessary. If certain information is omitted from the Signaling_Peer option item, a predefined default value is used. For example, when there is no signaling peer address information, the source address of the RA_Enhanced message is used as the signaling peer address.

  As shown in FIG. 3, when the network uses stateful address management, the MN 101 obtains address information via the DHCP mechanism (DHCP_Request transmission (step S3009) and DHCP_Reply reception (step S3011)). . It will be apparent to those skilled in the art that the Signaling_Peer option item described above can be embedded in a DHCP_Reply message.

  After receiving the Signaling_Peer option item from the RA_Enhanced message or the DHCP_Reply message, the MN 101 updates the message related information of the signaling protocol. For example, in the case of NSIS, the MN 101 updates the NTLP layer MA.

  In the address formation process, the MN 101 acquires the same address that was previously used in the MAG 103. Therefore, when the MN 101 transmits a signaling message from the new location 111, the MN 101 uses the stored message association information (Message Association) instead of the peer discovery process trigger. The MN 101 transmits an Msg_C_Enhanced message to the peer indicated by the new message related information, for example, the MAG 109 (step S3013). In the case of NSIS, this Msg_C_Enhanced message is delivered in the C mode described in Non-Patent Document 6, and is delivered directly to the MAG 109, for example.

  However, since there is no usable signaling state before MAG 109, MAG 109 performs Q-mode signaling described in Non-Patent Document 6 to find an actual route, and constructs an appropriate state. Therefore, the MN 101 includes a “discovery flag” for instructing the MAG 109 that the signaling route discovery process should be executed in the Msg_C_Enhanced message. This discovery process includes building a state at a new location 111, and if necessary, the message includes the address and port number used, the encryption method used, security-related information, and the like.

  The Msg_C_Enhanced message includes “route discovery information”. This is used by the MAG 109 to discover a peer for transferring the Msg_Q message that is a signaling message. Therefore, “route discovery information” includes address information of the MN 101 and the CN 107, for example. In the case of NSIS, transmission of the Msg_Q message actually involves exchanging three messages (step S3015). In LMA 105, the relevant state for the old session can be reused, so the signaling message is delivered directly to CN 107 in C mode (step S3017). Then, a new state is established between the MN 101 and the CN 107 (step S3019).

  Since the Msg_C_Enhanced message, which is a signaling message, is delivered using the C mode, prior information is necessary to interpret it. For example, the signaling payload of the message is encrypted using the key negotiated between the MN 101 and the MAG 103 in the Q mode exchange as in step S2013. Therefore, in order for the MAG 109 to analyze the contents of the Msg_C_Enhanced message, information on the previous state, for example, the signaling context should be obtained from the MAG 103. The signaling context includes, for example, a session ID, a security key, a port number used for communication, an authentication token, and the like.

  FIG. 4 is a sequence chart showing an example of a signaling context transmission process sequence according to the first embodiment of the present invention. As shown in FIG. 4, when the MN 101 transmits an Msg_C_Enhanced message to the MAG 109, the MN 101 includes the previous (previously connected) peer information in the Msg_C_Enhanced message. The previous peer information corresponds to connection station information related to a connection station to which the above-described mobile terminal (MN) has previously connected. In this case, the previous peer is MAG103.

  Upon receipt of the Msg_C_Enhanced message, the MAG 109 requests a signaling context from the MAG 103 using a Cxt_Req message (step S4001). The Cxt_Req message is transmitted toward the address indicated by the previous peer information of the Msg_C_Enhanced message. Information included in the Cxt_Req message is, for example, identification information of the MN 101, an address of the MAG 109 as the requester's address, signaling session identification information, a context index map, and the like.

  When the MAG 103 receives the Cxt_Req message, the MAG 103 collects the signaling context information indicated by the identification information of the MN 101 and the signaling session identification information. The MAG 103 forms a CxT_Rsp message, and the payload of the message includes a part of the signaling context indicated by the “context index map” of the Cxt_Req message. The CxT_Rsp message is transmitted from the MAG 103 to the MAG 109 by setting the “requester address” of the Cxt_Req message as the “destination address” (step S4003).

  By using the context information in the CxT_Rsp message, the MAG 109 can accurately analyze the signaling payload in the Msg_C_Enhanced message and continue the signaling process, eg, transfer of the Msg_Q message (step S3015).

  If the context collection is not successful, the MAG 109 can rely on Q-mode processing as shown in step S2013 to establish a connection with the MN 101. There are various reasons for the failure to obtain the context. For example, the Cxt_Req message does not reach the MAG 103, or does not have the context information requested by the MAG 103. When the context information requested by the MAG 103 cannot be supplied, the MAG 103 replaces the context information (Context Information) field of the CxT_Rsp message with an error code.

  2 and 3, it is assumed that the MAG can know whether the MN 101 has connected to the LMD 100 for the first time. This is to simplify the explanation. Those skilled in the art will appreciate that the present invention can be processed without such assumptions. For example, the MAG can always perform the processing as shown in FIG. That is, an RA_Enhanced message including signaling peer information can always be transmitted regardless of the status of the MN 101. The MN 101 can determine how to use such information based on the local policy.

  FIG. 5 is a configuration diagram showing an example of the configuration of the MN according to the first embodiment of the present invention. The MN 101 is composed of two main components. The constituent elements are an AMF (Address Management Function) 501 and a CSF (Control Signaling Function) 503. In addition, the component of MN is an example and is not restricted to this. The AMF 501 manages signaling related to address formation such as transmission of RS messages and reception of RA_Enhanced messages. The AMF 501 also updates the CSF using the information in the received RA_Enhanced message. The CSF 503 manages and processes resource control signaling such as generation and transmission of MSG_C_Enhanced messages.

  FIG. 6 is a configuration diagram showing an example of the configuration of the MAG according to the first embodiment of the present invention. The MAG 600 (MAG 103, MAG 109) includes four components, for example, AAA 601, AMM (Address and Mobility Management) 603, CSF (Control Signaling Function) 605, and SCM (Signaling Context Management) 607. Note that the components of the MAG are merely examples, and the present invention is not limited to this. The AAA 601 performs access control for MN access to the network, and the AMM 603 starts address and mobility control processing.

  The AMM 603 performs address and mobility management in the MN such as reception of RS messages and transmission of RA_Enhanced messages. The AMM 603 communicates with the LMA 105, for example, performs PMIP processing as shown in FIG. Further, the AMM 603 acquires information related to signaling from the CSF 605 and embeds it in the address formation message transmitted to the MN. The CSF 605 controls signaling between the MAG and the MN, and starts signaling context transfer between MAGs managed by the SCM 607.

  Those skilled in the art will appreciate that the solution described above can be generalized to apply to a normal mobile IP environment. In that case, the access router of the MN executes a new function defined in the MAG 103 and the MAG 109.

<Second Embodiment>
An example of the network configuration in the second embodiment of the present invention is shown in FIG. 7 includes an AAA function entity (hereinafter also referred to as an AAA entity) 701 connected to the MAG 103 and the MAG 109 in addition to the one (entity) shown in FIG. Those skilled in the art will appreciate that the AAA entity 701 is a logical entity. Indeed, the AAA entity 701 can be a plurality of nodes that can communicate and share information. AAA entity 701 assists in transferring signaling context information between MAG 103 and MAG 109.

  FIG. 8 is a sequence chart showing an example of a processing sequence when having the AAA function in the second embodiment of the present invention. When the MN 101 connects to the MAG 109 (step S8001), the identification information of the MN 101 needs to be supplied to the MAG 109 because it is requested by PMIP. This is done through different means, for example via an EAP (Extended Authentication Protocol) message not shown.

  After acquiring the identification information of the MN 101, the MAG 109 contacts the AAA entity 701 for authentication and authorization. When Diameter Network Access Server Application (see Non-Patent Document 5) is used, an AA_Request message is transmitted to the AAA entity 701 (step S8003). “Context Transfer Request” AVP (Attribute-Value-Pair) is included in AA_Request.

  The format of “Context Transfer Request” AVP is the same as that of other AVPs (see Non-Patent Document 5), and has a predetermined AVP code agreed between MAG 109 and AAA entity 701. The “Context Transfer Request” AVP format includes, for example, an IP address including a signaling session ID. The MAG 109 places an IP address to receive the context in the IP address field.

  Upon reception of AA_Request, AAA entity 701 records the identification information of MAG 109 and responds with a message of AA_Answer (step S8005). The format of AA_Answer is defined in Non-Patent Document 5, and the content depends on the arrangement configuration.

  When the AAA entity 701 finds “Context Transfer Request”, it transfers “Context Transfer Request” AVP to the previous MAG, eg, MAG 103, using an AAA message, eg, AS_Request (see Non-Patent Document 5). (Step S8007). “Context Transfer Request” AVP is embedded in AS_Request. It is obvious to those skilled in the art that the “Context Transfer Request” AVP is transmitted to the MAG 103 via another AAA message depending on the arrangement configuration. When the MAG 103 receives the AS_Request, the resource allocated to the signaling session is released, and if necessary, responds to the AAA entity 701 with an ASA message (not shown) (not shown).

  When the MAG 103 receives the “Context Transfer Request” AVP, the requested context information is transmitted to the MAG 109 indicated by the AVP via the CxT_Rsp message (step S8009). The format of the CxT_Rsp message is the same as that of the CxT_Rsp message in the first embodiment.

  On the other hand, PMIP processing and MN address formation at a new location are executed in step S8011. The steps after this step are like the procedure shown in FIG. After acquiring the address, the MN 101 transmits an Msg_C_Enhanced signaling message to the MAG 109 (step S8013). The contents of Msg_C_Enhanced are the same as Msg_C_Enhanced shown in FIG. 3 except for “previous peer information”. The following processing in FIG. 8 is the same as that shown in FIG.

  FIG. 9 is a configuration diagram showing an example of the configuration of the MAG according to the second embodiment. The constituent elements of MAG900 (MAG103, 109) are merely examples, and the present invention is not limited to this. In this configuration, AAA 901 obtains the associated control signaling peer information and embeds it in AAA signaling to AAA entity 701. The AAA 901 causes the SCM 907 to execute signaling context transfer when receiving a command from the AAA entity 701. The AMM 903 performs address and mobility management. The CSF 905 performs signaling control between the MAG and the MN. The SCM 907 manages a signaling context.

  Hereinafter, an example of the format of each message described in the first and second embodiments will be described. FIG. 10 shows an example of the format of Signaling_Peer used in the RA_Enhanced message shown in FIG. The encapsulation and encryption of RA_Enhanced is the same as the Router Advertisement defined in Non-Patent Document 4 above. Signaling_Peer starts from a “Type” field 1001. The “Type” field 1001 indicates what type of signaling peer exists, such as “On-path RSVP”, “On-path NSIS”, “Off-path Diameter”, and the like.

  A “Length” field 1003 indicates the total length of the option. An “Address Info” field 1005 indicates an address of a signaling peer, for example, an IP address. A “Port Number” field 1007 indicates a port number at which the signaling peer accepts a message. In the case of PMIP, since RA_Enhanced is unicast to MN 101, the port number is unique to MN 101. A “Transport Information” field 1009 indicates a transmission protocol used for signaling, for example, TCP (Transmission Control Protocol), UDP (User Datagram Protocol), SCTP (Stream Control Transmission Protocol), and the like.

  The “Cipher Suit Info” field 1011 is shown when encryption is used for signaling. It indicates the cryptographic mechanisms and key management schemes supported by the signaling aware node, eg AES, 3DES, etc. It will be obvious to those skilled in the art that there are multiple Signaling_Peer options in RA_Enhanced if different signaling mechanisms are supported in the network.

  FIG. 11 shows an example of the contents of Msg_C_Enhanced shown in FIG. The actual encryption and header setting of Msg_C_Enhanced depends on the signaling application. The “Type” field 1101 indicates the nature of the signaling message, for example, “RESERVE” in the case of NSIS, and “RESV” in the case of RSVP. A “Length” field 1103 indicates the total length of the message. The “Discovery Flag” field 1105 indicates that discovery of the signaling path should be started when the message receiver transfers the message, for example, when transmitting in the Q mode in the case of NSIS.

  A “Path Discovery Info” field 1107 includes related information for signaling path discovery, for example, address information of a transmission source and a destination in a data flow, a port number, and the like. The “Previous Peer Info” field 1109 includes information on the most recent signaling peer of the MN 101, for example, the MAG 103. The “Signaling Payload” field 1111 includes information specific to the signaling application. In some cases, this item is protected by cryptographic means. In this case, the “Cipher Suit Info” field 1113 includes information on the scheme used, for example, AES (Advanced Encryption Standard).

  FIG. 12 shows an example of the contents of the elements of the signaling context (context information). The “MN Identifier” field 1201 includes information regarding the identification information of the MN 101. Due to PMIP, the MN needs to have unique identification information in the LMD 100. The “Session Identifier” field 1203 includes information about the signaling session. For example, in the case of NSIS, it is a session ID.

  The “Security Key” field 1205 includes key data for encryption protection of the signaling message. The “Address Information” field 1207 includes information about the source and destination of data communication related to the signaling session. An “Authorization Token” field 1209 includes session authorization information. For example, it is a permission Token approved by the MN 101 for a certain resource request.

  FIG. 13 shows an example of the format of the CxT_Req message shown in FIG. The “Destination Address” field 1301 includes the address of the node having the required context information, for example, the MAG 103 IP address. The “Requester Address” field 1303 includes address information of the requesting node, for example, the MAG 109 IP address. The “MN Identifier” field 1305 includes identification information of the MN in PMIP.

  The “Session Identifier” field 1307 contains information on the signaling session with which the context is associated. The MAG 109 can acquire this session information from Msg_C_Enhanced. The “Context Index Map” field 1309 is a bitmap index indicating a requested part of the signaling context information shown in FIG. When the item of the “Context Index Map” field 1309 is omitted, it indicates that all contents of the signaling context are transmitted.

  FIG. 14 shows an example of the format of the CxT_Rsp message shown in FIG. A “Destination Address” field 1401 includes address information of a node that requests context information. This is obtained from the “Requester Address” field 1303 of the CxT_Req message. In the case of the processing of FIG. 8, this is obtained from the “IP Address” field 1507 of the “Context Transfer Request” AVP field of the AS_Request message. In this example, this is the IP address of MAG109.

  A “Source Address” field 1403 includes information about a node that supplies context information, for example, the address of the MAG 103. The “MN Identifier” field 1405 includes information on identification information of the MN 101 used in PMIP in the LMD 100. The “Session Identifier” field 1407 contains signaling session information with which the context is associated. A “Context Information” field 1409 includes information on a signaling context indicated by a “Context Index Map” field 1309 or a “Context Index Map” field 1511 described later.

  FIG. 15 shows an example of the contents of “Context Transfer Request” AVP used in the AS_Request message. The “AVP Code” field 1501 includes a predetermined code for indicating the type of AVP. The “Flag” field 1503 includes a flag necessary for signaling, and indicates, for example, whether or not this AVP requires interpretation. A “Length” field 1505 indicates the length of the AVP.

  The “IP Address” field 1507 includes information about a node that requests context information, for example, the MAG 109. The “Session Identifier” field 1509 contains session identification information associated with the requested context. The “Context Index Map” field 1511 includes a bitmap index indicating a related field of requested context information. If the “Context Index Map” field 1511 is omitted, it means that all context information is requested.

<Third Embodiment>
As shown in the first embodiment, the MAG 109 acquires information about the previous signaling peer of the MN 101 through Msg_C_Enhanced transmitted from the MN 101, and starts a signaling context transfer process. To speed up processing, the MAG 109 can also obtain information about previous signaling peers from other means.

  One possible means is to embed it in a PMIP message (see Non-Patent Document 3). For example, an additional “Signaling Peer Info” option is embedded in the PBU message. The new option includes the address of the signaling peer for the current MAG, for example the address of the MAG 109. The LMA 105 stores “Signaling Peer Info” in an additional field of the binding cache entry.

  If the information exists, the LMA 105 replaces it with the newly received option, and puts the peer information before replacement with the “Signaling Peer Info” option of the PBA message for responding to the MAG 109. When the MAG 109 receives a PBA message having a “Signaling Peer Info” option, the MAG 109 requests context information from the node indicated by the option by transmitting CxT_Req. If the option does not exist, the MAG 109 waits for Msg_C_Enhanced or performs a message association negotiation with the MN 101.

  Another method for the MAG 109 to acquire the previous peer information is to acquire it via an AAA entity 701 as shown in FIG. “Signaling Peer Info” AVP can be embedded in AA_Request transmitted from MAG 109 to AAA entity 701. The AAA entity 701 stores this “Signaling Peer Info” along with the session entry.

  In the same LMD 100, when “Signaling Peer Info” in the session exists in the AAA entity 701, the AAA entity 701 embeds the information in AA_Answer transmitted to the MAG 109. If the MAG 109 finds “Signaling Peer Info” AVP in AA_Answer, the MAG 109 starts context transfer processing for the node indicated by “Signaling Peer Info” AVP. For example, CxT_Req is transmitted to the MAG 103.

  FIG. 16 is a configuration diagram showing an example of the configuration of the MAG according to the third embodiment. Note that the components of the MAG 1600 (MAG 103, 109) are merely examples, and the present invention is not limited to this. This configuration is the same as that shown in FIG. 6, but AAA 1601 or AMM 1603 starts SCM 1607 for signaling context transfer. The CSF 1605 performs signaling control between the MAG and the MN. The SCM 1607 manages a signaling context.

<Fourth embodiment>
As described in the third embodiment, the MAG 109 can acquire the context from the MAG 103 before receiving Msg_C_Enhanced from the MN 101. This is one process of the present invention. In this case, the MAG 109 does not need to include the Signaling_Peer option item in the RA_Enhanced message. If there is no Signaling_Peer option item, the MN 101 continues to send signaling messages to the address of the previous peer, eg, the address of the MAG 103.

  Since it has a signaling context from MAG 103, MAG 109 intercepts the message and processes it as if it were MAG 103. The MAG 109 starts signaling path discovery when transferring a signaling message toward the LMA 105. In this case, when the MN 101 further moves to a new MAG, it is not necessary to change the signaling state.

<Fifth embodiment>
In the above description, it is assumed that the MAG, eg, MAG 103, 109, is a signaling awareness node (eg, QNE). However, the present invention can be implemented even if the MAG is not a signaling recognition node. In the case where there is a signaling recognition node that cooperates with the MAG at a physically different position, the implementation can be performed with a slight improvement. For example, the main change is to accept Msg_C_Enhanced at the signaling awareness node instead of MAG, so that the address used in the message points to the signaling awareness node associated with the MAG.

  Each functional block used in the description of each of the above embodiments is typically realized as an LSI that is an integrated circuit. These may be individually made into one chip, or may be made into one chip so as to include a part or all of them. The name used here is LSI, but it may also be called IC, system LSI, super LSI, or ultra LSI depending on the degree of integration. Further, the method of circuit integration is not limited to LSI's, and implementation using dedicated circuitry or general purpose processors is also possible. An FPGA (Field Programmable Gate Array) that can be programmed after manufacturing the LSI, or a reconfigurable processor that can reconfigure the connection and setting of circuit cells inside the LSI may be used. Further, if integrated circuit technology comes out to replace LSI's as a result of the advancement of semiconductor technology or a derivative other technology, it is naturally also possible to carry out function block integration using this technology. For example, biotechnology can be applied.

  The mobile terminal and the connection station apparatus according to the present invention, when the connection destination changes due to movement, wastes network resources and interrupts service to the MN because a state along a new route (signaling route) is not established. This is useful for mobile terminals and connection station devices that establish a signaling path between a mobile terminal and a communication terminal that is a communication partner when the connection destination of the mobile terminal is changed due to movement. It is.

The block diagram which shows an example of the network structure in the 1st Embodiment of this invention The sequence chart which shows an example of the processing sequence when MN which concerns on the 1st Embodiment of this invention joins LMD for the first time The sequence chart which shows an example of the processing sequence when MN which concerns on the 1st Embodiment of this invention connects with MAG109 The sequence chart which shows an example of the sequence of the signaling context transmission process in the 1st Embodiment of this invention The block diagram which shows an example of a structure of MN which concerns on the 1st Embodiment of this invention The block diagram which shows an example of a structure of MAG which concerns on the 1st Embodiment of this invention The block diagram which shows an example of the network structure in the 2nd Embodiment of this invention The sequence chart which shows an example of the processing sequence at the time of having the AAA function in the 2nd Embodiment of this invention The block diagram which shows an example of a structure of MAG which concerns on the 2nd Embodiment of this invention. Example format of Signaling_Peer used in RA_Enhanced message in the first exemplary embodiment of the present invention Format of an example of contents of Msg_C_Enhanced in the first exemplary embodiment of the present invention Example format of content of signaling context element in the first exemplary embodiment of the present invention Example format of CxT_Req message in the first exemplary embodiment of the present invention Example format of CxT_Rsp message in the first exemplary embodiment of the present invention Format of an example of the content of “Context Transfer Request” AVP used in the AS_Request message in the second embodiment of the present invention The block diagram which shows an example of a structure of MAG which concerns on the 3rd Embodiment of this invention. Configuration diagram showing an example of a conventional network configuration

Explanation of symbols

100 LMD
101 MN
103, 109, 600, 900, 1600 MAG
105 LMA
107 CN
111 New location 501 AMF
503, 605, 905, 1605 CSF
601, 901, 1601 AAA
603, 903, 1603 AMM
607, 907, 1607 SCM
701 AAA entity 1001, 1101 Type field 1003, 1103, 1505 Length field 1005 Address Info field 1007 Port Number field 1009 Transport Information field 1011, 1113 Cipher Suit Info field 1105 Discovery Flag field 1107 Path Discovery Info field 1109 Previous Peer Info field 1111 Signaling Payload field 1201, 1305, 1405 MN Identifier field 1203, 1307, 1407, 1509 Session Identifier field 1205 Security Key field 1207 Address Information field 1209 Authorization Token field 1301, 1401 Destination Address field 1303 Requester Address field 1309, 1511 Context Index Map field 1 403 Source Address field 1409 Context Information field 1501 AVP Code field 1503 Flag field 1507 IP Address field 1701 Access points 1703, 1705, 1707 MN
17001 Downlink 17003, 17005, 17007 Uplink

Claims (14)

In a communication system in which a mobile terminal communicates with a communication device that is a communication partner of the mobile terminal via any one of a plurality of connection station devices arranged in a predetermined domain, the mobile terminal is connected by the movement so far A configuration in which the second connection station apparatus constructs a signaling path between the mobile terminal and the communication apparatus via a second connection station apparatus newly connected from the first connection station apparatus. The mobile terminal in the communication system,
Receiving means for receiving, from the second connection station device, a first message for the mobile terminal itself to acquire connection station information relating to the first connection station device;
Message generating means for generating a second message including connection station information related to the first connection station device based on the received first message;
Transmitting means for transmitting the generated second message to the second connection station device;
Mobile terminal provided.   The mobile terminal according to claim 1, wherein the first message includes connection station information related to the second connection station apparatus.   The mobile terminal according to claim 1 or 2, wherein a proxy node performs processing of the first connection station device and / or the second connection station device. In a communication system in which a mobile terminal communicates with a communication device that is a communication partner of the mobile terminal via any one of a plurality of connection station devices arranged in a predetermined domain, the mobile terminal is connected by the movement so far The connection station device to be newly connected to construct a signaling path between the mobile terminal and the communication device through a connection station device newly connected from the connection station device before movement,
When it is determined that the mobile terminal has moved from the connection station device before movement, which is a connection station device in the predetermined domain that was connected before movement, connection station information regarding the connection station device before movement is acquired. Message generating means for generating a first message for
Transmitting means for transmitting the generated first message to the mobile terminal;
A message transmitted from the mobile terminal based on the first message, including connection station information related to the connection station device before the movement and processing request information indicating that a new signaling path should be established. Receiving means for receiving two messages;
Control means for constructing a signaling path between the mobile terminal and the communication device via the connection station device itself,
The message generation means is held in the connection station device before movement based on the received connection station information regarding the connection station device before movement, and the mobile terminal passes through the connection station device before movement. Generating a third message for obtaining communication state information constructed for communicating with the communication device;
The transmission means transmits the generated third message to the connection station device before movement,
The reception means receives a fourth message including the communication state information transmitted from the connection station device before movement based on the third message,
The connection station device that constructs the signaling path based on the received communication state information and the processing request information.   The connection station apparatus according to claim 4, wherein the first message includes connection station information regarding the connection station apparatus itself.   The connection station apparatus according to claim 4 or 5, wherein the second message includes address information of the communication apparatus. In a communication system in which a mobile terminal communicates with a communication device that is a communication partner of the mobile terminal via any one of a plurality of connection station devices arranged in a predetermined domain, the mobile terminal is connected by the movement so far The connection station device to be newly connected to construct a signaling path between the mobile terminal and the communication device through a connection station device newly connected from the connection station device before movement,
When it is determined that the mobile terminal has moved from the connection station device before the movement, which is a connection station device in the predetermined domain that was connected before the movement, the mobile terminal is held in the connection station device before the movement, and the movement Message generating means for generating a first message for acquiring communication state information constructed for a terminal to communicate with the communication device via the connection station device before moving;
Transmitting means for transmitting the generated first message to a predetermined server;
3rd including the communication state information transmitted from the connection station device before movement based on the second message including the first message transmitted from the predetermined server to the connection station device before movement. Receiving means for receiving, from the mobile terminal, a fourth message including processing request information indicating that a construction process for a new signaling path should be performed;
Control means for constructing a signaling path between the mobile terminal and the communication device via the connection station device itself based on the received communication state information and the processing request information,
A connection station device provided.   The connection station apparatus according to claim 7, wherein the first message includes predetermined code information agreed in advance between the predetermined server and the connection station apparatus.   The connection station apparatus according to claim 7 or 8, wherein the fourth message includes address information of the communication apparatus. In a communication system in which a mobile terminal communicates with a communication device that is a communication partner of the mobile terminal via any one of a plurality of connection station devices arranged in a predetermined domain, the mobile terminal is connected by the movement so far The connection station device to be newly connected to construct a signaling path between the mobile terminal and the communication device through a connection station device newly connected from the connection station device before movement,
When it is determined that the mobile terminal has moved from the connection station device before movement, which is a connection station device in the predetermined domain that was connected before movement, acquisition of connection station information regarding the connection station device before movement Message generating means for generating a first message including information indicating a request;
Transmitting means for transmitting the generated first message to a management device or a predetermined server that manages the plurality of connection station devices arranged in the predetermined domain;
A second message including connection station information related to the connection station device before movement transmitted from the management device or the predetermined server based on the first message, and a new signaling path transmitted from the mobile terminal Receiving means for receiving a message including processing request information indicating that the construction processing should be performed;
Control means for constructing a signaling path between the mobile terminal and the communication device via the connection station device itself,
The message generation means is held in the connection station device before movement based on the received connection station information regarding the connection station device before movement, and the mobile terminal passes through the connection station device before movement. Generating a third message for obtaining communication state information constructed for communicating with the communication device;
The transmission means transmits the generated third message to the connection station device before movement,
The reception means receives a fourth message including the communication state information transmitted from the connection station device before movement based on the third message,
The connection station device that constructs the signaling path based on the received communication state information and the processing request information. When the receiving means does not receive the processing request information from the mobile terminal,
The said control means performs construction of the said signaling path | route based on the said communication status information, when the signaling transmitted to the connecting station apparatus before the movement from the said mobile terminal is received by the said receiving means. The connection station device described.   12. The connection station according to claim 4, wherein the third message includes at least identification information of the mobile terminal, address information of the connection station device itself, and identification information of a signaling session. apparatus.   The connection station apparatus according to any one of claims 4 to 12, wherein the communication state information is information including one or more of a session ID, a security key, a port number, and an authentication token.   The connection station apparatus according to any one of claims 4 to 13, wherein a proxy node performs processing of the connection station apparatus before moving and / or the connection station apparatus.

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