JP2006197107A - Method and system for connecting networks of different types - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and a system for connecting networks of different types, capable of performing high speed seamless handover between networks of different types where mobility management of a terminal is realized by a different method, without mounting an extra middle ware on the terminal. <P>SOLUTION: An FA arranged in a PDG 102 for mediating an HA and a WLAN AN transforms a tunnel-setting request from a UE in a WLAN area into a position registration request in a mobile IP, and an FA arranged in the HA and a GGSN transforms a PDP context generation request from a UE, in a 3GPP system, into a position registration request in the mobile IP. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a heterogeneous network connection method and a heterogeneous network connection system.

  In recent years, as a transition technology to the fourth generation mobile communication system, the current third generation (3G) mobile communication system and a wireless local area network (WLAN) are merged, and the 3G system has a wide range. 3G / WLAN interworking technology that provides users with a wide communication area and broadband access of the WLAN system has attracted attention. Non-Patent Document 1 and the like have proposed a seamless handover technique that allows a user to move between different 3G / WLAN wireless access schemes without being aware of it.

  Non-Patent Document 1 discloses a mobility management method between different networks of a 3G network and a WLAN network using mobile IP. The network configuration of the heterogeneous network connection system disclosed in Non-Patent Document 1 will be described below with reference to FIG.

  As shown in FIG. 5, a foreign agent (FA) in a 3G network is arranged in a GGSN (Gateway GPRS Support Node), and an FA in a WLAN interworking system is arranged in an access router (GW: Gateway). In addition, a home agent (HA) that manages the correspondence between the home address of the terminal and the care-of address is arranged on a packet data network (PDN).

  Here, it is assumed that the UE (User Equipment) is receiving service in the 3G network and eventually moves to the WLAN area. The location registration update process in the WLAN after movement will be described with reference to FIG.

  In FIG. 6, in step (hereinafter abbreviated as “ST”) 11, the UE moves to the WLAN network. In ST 12, if the UE performs an authentication procedure in the WLAN and access permission falls, in ST 13, the WLAN In order to search for an FA in the area, an agent search packet is transmitted.

  In ST14, the FA (access router) sends an agent advertisement back to the UE, so that the UE acquires a care-of address (CoA), and in ST15, the UE takes the agent advertisement acquired from the FA as an opportunity to the HA. Registration request to the FA.

  In ST16, a set of the MAC address, home address and care-of address of the UE is extracted from the registration request received by the FA from the UE, and stored in the table of the own node. In ST17, the FA acts as a proxy for the UE registration request to the HA.

  In ST18, a set of the home address and care-of address of the UE is extracted from the UE registration request received from the FA by the HA and stored in the table of the own node. In ST19, the HA sends a registration response to the FA, and in ST20, the FA transfers the registration response sent from the HA to the UE.

  Thus, the location registration of the UE is updated by the above-described procedure. Thus, when the HA receives a packet having the UE's home address as the destination address from a communication partner (Correspondent Node: CN), the HA refers to the table of the own node and determines the transfer destination of the received packet. In this case, since it is understood that the forwarding destination is FA (access router), the destination address is FA, the transmission source address is HA, the received IP packet is encapsulated with IPinIP, and the IP packet is transmitted to the FA. To do.

  The FA receives the packet encapsulated from the HA and extracts the original IP packet by decapsulating the received packet. Then, the extracted IP packet is transmitted to the UE.

By this location management based on a series of mobile IPs, the UE can complete movement between different networks while continuing communication.
Apostolis K. Salkintzis, Chad Fors and Rajesh Pazhyannur, “WLAN-GPRS integration for next-generation mobile data networks”, IEEE Wireless Communications, vol.9, no.5 October 2002, pp.112-124

  However, in the technique described in Non-Patent Document 1 described above, when a mobile terminal performs a seamless handover between a 3G system and a WLAN system, middleware for realizing mobile IP is newly installed in the terminal (UE). This increases the amount of software development, leading to an increase in terminal cost.

  In addition, since the location management process using the mobile IP is performed after performing an access procedure (authentication, tunnel setting between the terminal and the gateway device) peculiar to the network to be accessed, the time until the handover is completed is increased. End up.

  The present invention has been made in view of the above points, and it is possible to perform seamless handover at high speed between heterogeneous networks that realize movement management of terminals by different methods without installing new middleware in the terminals. An object of the present invention is to provide a network connection method and a heterogeneous network connection system.

  A heterogeneous network connection method according to the present invention is a heterogeneous network connection method for connecting a first communication system and a second communication system different from the first communication system, and is provided in a host device of the first communication system. The first foreign agent converts the protocol used in the first communication system to mobile IP, and the second foreign agent provided in the host device of the second communication system different from the first communication system uses in the second communication system. Protocol to be converted to mobile IP.

  According to this method, the mobile terminal performs a seamless handover between the first communication system and the second communication system using an existing protocol such as a protocol used in the first communication system and a protocol used in the second communication system. Therefore, it is not necessary to newly install new middleware for realizing mobile IP in the mobile terminal, and an access procedure peculiar to the network to be accessed can be omitted, so that handover is performed at high speed. be able to.

  According to the present invention, seamless handover can be performed at high speed between heterogeneous networks that implement terminal mobility management by different methods without installing new middleware in the terminals.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment)
FIG. 1 is a network configuration diagram of a heterogeneous network connection system according to an embodiment of the present invention. This heterogeneous inter-network connection system is a system in which different 3G and WLAN access methods are accommodated in a common 3G core network to provide seamless connection to users.

  The UE 101 is used by 3GPP subscribers to access the WLAN network and is equipped with a USIM (Universal Subscriber Identity Module) card. A WLAN UE is a terminal such as a PDA (Personal Digital Assistant), a laptop computer with a WLAN card, a UICC (Universal Integrated Circuit Card) card reader and an appropriate software application in its configuration, operation and software environment. May be the type.

  The UE 101 has the following functions. WLAN registration, WLAN access authentication based on EAP (Extensible Authentication Protocol) method, local IP address acquisition, secure tunnel establishment to PDG, remote IP address acquisition, service provided in operator PS domain Such as access.

  A packet data gateway (PDG) 102 mediates access between the 3GPP PS domain and the WLAN AN, and the 3GPP PS-based service is accessed via the PDG in the 3G core network. The PDG 102 has the following functions. Assigning the WLAN UE's remote IP address to the WLAN UE (if none has been assigned), establishing a secure tunnel between the UE and PDG requested by the WLAN UE, to / from WLAN-3G connected users Packet data routing, MIP FA function, etc.

  Next, in the inter-heterogeneous network connection system having the above-described configuration, it is assumed that the UE 101 is receiving service in the 3G network and eventually moves to the WLAN area, and the location registration update processing in the WLAN after the movement will be described with reference to FIG. To do.

  In FIG. 2, the UE 101 detects a WLAN area and determines to perform communication after the detection via the WLAN area. When the WLAN authentication process is performed between the UE 101 and the WLAN AN and the authentication procedure is not completed only by the WLAN AN, the authentication process is completed in cooperation with the AAA of the 3G network.

  The UE 101 that has been successfully authenticated acquires an IP address (hereinafter referred to as “local IP”) necessary for routing in the WLAN AN by DHCP (Dynamic Host Configuration Protocol) from the WLAN AN. After that, the IP address of the PDG is obtained from the DNS (Domain Name System) in order to search for the gateway (PDG102) that guarantees the arrival of the packet from the communicating partner node (CN) (equivalent to FA search of mobile IP). To do.

  The network between the searched PDG 102 and the UE 101 is also assumed to be connected via a public network, and it is considered that secure communication is performed between the PDG 102 and the UE 101 using IPsec (IP security) or the like. . In such a case, a secure tunnel is set between the PDG 102 and the UE 101 using IKE (Internet Key Exchange) described in RFC2409. At the end of the IKE secure tunnel setup procedure, the PDG 102 authenticates the user of the UE 101 in order to confirm whether or not the tunnel has been correctly set up with the UE 101 that should set up the tunnel. This user authentication packet includes the authentication information of the UE 101, and the PDG 102 performs user authentication with the AAA of the home network based on the information.

  Upon receiving the user authentication request (tunnel establishment request) from the UE 101, the PDG 102 converts the tunnel establishment request from the UE 101 into a location registration request in the mobile IP as shown in FIG. Here, since the PDG 102 does not know the address of the HA (Home Agent) currently used by the UE 101, the PDG 102 instructs the Diameter processing unit 302 to inquire the AAA about the HA address currently used by the UE 101 (AA -Mobile-Node-Request).

  The AAA of the home network to which the UE 101 belongs receives the Diameter packet (HA search request packet) from the PDG 102 to derive the HA address and home address (hereinafter referred to as “remote IP”) that the UE 101 is currently using. The result is notified to the PDG 102 (AA-Mobile-Node-Answer).

  The PDG 102 notified of the remote IP address and HA address from the AAA stores the acquired remote IP address and HA address in a predetermined area of the mobile IP location registration request packet generated by the tunnel establishment request from the UE 101, and HA The mobile IP processing unit 303 sends the mobile IP location registration request to the mobile IP.

  For this reason, processing in the HA is the same as that of normal mobile IP, and the HA transmits a packet addressed to the UE 101 toward the PDG 102. Further, the PDG 102 that has received the mobile IP location registration response from the HA stores a pair of the local IP and the remote IP of the UE 101 and establishes a user authentication response (tunnel) to the UE 101 in order to establish a secure tunnel with the UE 101. Establish response) packet is sent out.

  With the above operation, the packet addressed to the UE 101 transferred from the HA to the PDG 102 reaches the UE 101 through the secure tunnel based on the local IP from the PDG 102.

  Next, when the UE 101 receives a service in the WLAN area and eventually leaves the WLAN area and continuously receives the service via the 3G network, the location registration update process in the 3G network will be described with reference to FIG.

  In FIG. 4, the UE 101 detects that it is more difficult to continue the service via the WLAN, for example, by moving away from the WLAN area, and performs registration (GPRS attachment) in the packet switching domain of the 3G network. However, if the UE is performing GPRS attachment even during communication via WLAN, GPRS attachment is not necessary.

  The UE 101 that has completed the GPRS attach process performs a process (PDP context activation request) for managing a session with a device (SGSN) on the 3G network side.

  The SGSN that has received the PDP context activation request from the UE 101 similarly performs a session management process (PDP context generation request) on a device (GGSN) serving as a gateway in the 3G packet switching domain.

  Upon receiving the PDP context generation request, the GGSN converts the PDP context generation request from the SGSN into a location registration request in Mobile IP as shown in FIG. Here, since the GGSN does not know the address of the HA currently used by the UE 101, it instructs the Diameter processing unit 302 to inquire the AAA about the HA address currently used by the UE 101 (AA-Mobile-Node). -Request).

  The AAA of the home network to which the UE 101 belongs receives the Diameter packet (HA search request packet) from the GGSN, derives the HA address and user IP address currently used by the UE 101, and sends the result to the GGSN. Notification (AA-Mobile-Node-Answer).

  The GGSN notified of the user IP address and the HA address from the AAA stores the acquired user IP address and the HA address in a predetermined area of the mobile IP location registration request packet generated by the PDP context generation request from the SGSN. The mobile IP processing unit 303 sends the mobile IP location registration request to the HA.

  For this reason, processing in the HA is the same as that of normal mobile IP, and the HA transmits a packet addressed to the UE 101 to the GGSN. In addition, the GGSN that has received the mobile IP location registration response from the HA holds a PDP context for managing the session of the UE 101 and sends a PDP context generation response packet to the SGSN. Further, the SGSN similarly holds a PDP context for the UE 101 and sends a PDP context activation acceptance packet to the UE 101.

  With the above operation, the packet addressed to the UE 101 transferred from the HA to the GGSN is transferred to the UE 101 by the existing 3G network protocol with the mobile IP tunnel terminated at the GGSN.

  In the above embodiment, the switching between the 3G network and the WLAN network is described as an example of area movement. However, the network switching may be performed for reasons such as the degree of network congestion and the level of usage charges. .

  In addition, when converting a tunnel establishment request sent from the UE and a PDP context generation request sent from the SGSN into a mobile IP location registration request, the PDG and GGSN do not know the HA address used by the user. As described above, the HA address may be known in advance by some means, and the mobile IP location registration request directly converted to the HA may be sent without going through the HA address resolution means by Diameter.

  As described above, according to the present embodiment, when the FA converts the tunnel establishment request from the UE and the PDP context generation request from the SGSN into the location registration request in the mobile IP, the UE uses the existing protocol to perform the 3G system. Can be seamlessly handed over to the WLAN system, so there is no need to newly install new middleware for realizing Mobile IP in the terminal, and the access procedure specific to the network to be accessed is omitted. Therefore, handover can be performed at high speed.

  The heterogeneous network connection method and heterogeneous network connection system according to the present invention perform high-speed seamless handover between heterogeneous networks that implement terminal mobility management in different methods without installing new middleware in the terminals. The present invention can be applied to a system composed of different networks of a 3G network and a WLAN network.

The network block diagram of the heterogeneous network connection system which concerns on embodiment of this invention Sequence diagram showing location registration update processing in WLAN Block diagram showing internal configuration of FA Sequence diagram showing location registration update processing in 3G network Network configuration diagram of heterogeneous network connection system disclosed in Non-Patent Document 1 Sequence diagram showing location registration update processing in the WLAN shown in FIG.

Explanation of symbols

101 UE
102 PDG
301 Protocol Conversion Unit 302 Diameter Processing Unit 303 Mobile IP Processing Unit

Claims (4)

A heterogeneous network connection method for connecting a first communication system and a second communication system different from the first communication system,
The first foreign agent provided in the host device of the first communication system converts the protocol used in the first communication system into mobile IP, and the second foreign agent provided in the host device of the second communication system performs the second communication. A heterogeneous network connection method characterized by converting a protocol used in the system into mobile IP.   A first foreign agent provided in the packet data gateway that mediates between the WLAN system and the home agent converts a tunnel setting request from a mobile terminal in the WLAN area into a location registration request in Mobile IP, and is provided in the GGSN of the 3GPP system. The method according to claim 1, wherein the second foreign agent converts a PDP context generation request from a mobile terminal in the 3GPP system into a location registration request in Mobile IP. A heterogeneous network connection system for connecting a first communication system and a second communication system different from the first communication system,
A first foreign agent provided in a host device of the first communication system and converting a protocol used in the first communication system into a mobile IP;
A second foreign agent provided in a higher-level device of the second communication system and converting a protocol used in the second communication system into mobile IP;
A heterogeneous network connection system comprising: The first foreign agent is provided in a packet data gateway that mediates between the WLAN system and the home agent, and converts a tunnel setting request from a mobile terminal in the WLAN area into a location registration request in mobile IP,
The heterogeneous network according to claim 3, wherein the second foreign agent is provided in a GGSN of a 3GPP system and converts a PDP context generation request from a mobile terminal in the 3GPP system into a location registration request in Mobile IP. Inter-connection system.

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