KR20110053786A - Method for supporting communication of multiple interface terminal - Google Patents

Abstract

PURPOSE: A method for supporting communication of a multiple interface terminal is provided to perform a continuous packet transmission and support a handover between heterogeneous access networks. CONSTITUTION: A MAT(MAG(Mobile Access Gateway) Address Translator) table is composed using received information. It is checked whether the received packets is for trasceiving data to a mobile node which performs a handover between heterogeneous access networks(306). If the packet is for being communicated with the mobile node, an NAT(Network Address Translation) of the packet is performed using the MAT table(308,310). The address transformed packet is transferred to the mobile node or the correspondent node(312).

Description

Method for supporting communication of multiple interface terminal

The present invention relates to a communication support method for a multi-interface terminal, and more particularly, to a communication support method for a multi-interface terminal in a domain network using a protocol for network-based mobility management.

The present invention is derived from a study conducted as part of the Ministry of Knowledge Economy's information and communication standard development support project.

MIPv4 / v6, Hierarchical Mobile IP (HMIP) and Fast Mobile IP (FMIP), or IP mobility protocols based on the MIPv4 / v6 developed to support mobility of mobile nodes, are mobile IP (MIP) protocols, which are mobility control technologies in all terminals and routers. The stack must be supported.

Proposed to improve this, PMIPv6 (Proxy Mobile IPv6) is a basic protocol for network-based mobility management, which is being standardized by IETF's Network-based Localized Mobility Management (NETLMM) Working Group. This requires the implementation of a protocol for supporting IP mobility only in the network, and does not require a separate protocol implementation for IP mobility management in the terminal.

In the PMIPv6 protocol, the handover of the terminal confirms the presence of the handover of the mobile node in the network, and through the terminal authentication process, a PBU (Proxy Binding Update) / PBU between the Mobile Access Gateway (MAC) and the Local Mobile Anchor (LMA). PBA (Proxy Binding Acknowledge) message is transmitted and received to create a tunnel, and through the generated tunnel is a packet transfer between the MN (Mobile Node) and CN (Corresondent Node).

After the tunnel is created, the MAG (Mobile Access Gateway) transmits a Router Advertisement (RA) message to the mobile node, and the terminal must newly configure its own IP through this message.

In this procedure, when a terminal with multiple interfaces performs handover between heterogeneous access networks, there is a problem in that packet forwarding is not continuous because the communication interface cannot be continuously used due to the change of the communication interface. .

In order to support UEs with multiple interfaces in PMIPv6, IETF's NETEXT Working Group is progressing standardization of requirements and handover scenarios for handover processing between heterogeneous access technologies for mobile nodes having multiple interfaces.

The present invention is derived from this background and aims to support handover between heterogeneous access networks and to perform continuous packet delivery for mobile nodes having multiple interfaces in a PMIPv6 domain.

The technical problem is a method of supporting communication of a multi-interface terminal in a domain network using a protocol for network-based mobility management, the method comprising: checking whether a received packet is a packet transmitted and received to a mobile node performing a handover between heterogeneous networks; ; Performing a network address translation (NAT) of the packet with reference to a mobile node address translation (MAT) table if the packet is transmitted / received to a mobile node that has performed heterogeneous network handover as a result of the checking; And forwarding the address-translated packet to the mobile node or the counterpart node.

On the other hand, the technical problem is that when a packet to a multi-interface terminal in which a local mobility mobility (LMA) heterogeneous network handover has been received, a mobile access gateway (MAG) to which the terminal belongs based on Binding Cache Entry (BCE) information Identifying information; Transmitting a packet to the identified Mobile Access Gateway (MAG) by the Local Mobility Anchor (LMA); Determining, by the mobile access gateway (MAG), whether the received packet is a packet transmitted to the terminal; If it is determined that the packet is transmitted to the terminal, the mobile access gateway (MAG) checks multiple interface (MIF) information and converts a network address into an IP address including communication interface identification information currently used by the terminal. Performing NAT (NAT); And delivering the address-translated packet to the terminal. It is also achieved by the communication support method of a multi-interface terminal.

In the method, when a packet is received from a multi-interface terminal in which a mobile access gateway (MAG) performs a handover between heterogeneous networks, the multi-interface (MIF) information is checked to include an IP including communication interface identification information previously used by the terminal. Performing network address translation (NAT) to an address; And transmitting the address translated packet to a local mobility anchor (LMA).

According to the present invention, even if a terminal having multiple interfaces in the PMIPv6 domain performs a handover between heterogeneous access networks, the MS performs handover without going through a connection reconfiguration step with the counterpart node CN, even though the MN address is changed. For one packet, the Mobile Access Gateway (MAG) translates the packet forwarded to the counterpart node 19 into an address consisting of previously used interface information, and the packet forwarded to the mobile node converts the interface information currently in use. By converting and forwarding to an address configured as, the packet can be continuously transmitted without undergoing a connection reconfiguration process between the mobile node MN and the counterpart node CN.

In addition, the signaling cost can be reduced by transmitting a smaller amount of signaling messages than the conventional technology for supporting handover between heterogeneous access networks using MIH.

The foregoing and further aspects of the present invention will become more apparent through the preferred embodiments described with reference to the accompanying drawings. Hereinafter, the present invention will be described in detail so that those skilled in the art can easily understand and reproduce the present invention through these embodiments.

1 is a block diagram of a communication system of a multi-interface terminal according to an embodiment.

The mobile node (MN) 18 has only IPv4 or IPv6, or has a dual stack and does not perform mobility related signaling. In one embodiment, the mobile node 18 has at least one interface to enable communication over at least one or more various wireless networks, such as WiMAX, Wi-Fi.

The mobile access gateway (MAG) 14 performs mobility support signaling on behalf of the mobile node 18, and performs a connection function and a routing function for the mobile node 18's network. In one embodiment, the mobile access gateway 14 is implemented in an access router.

Local Mobility Anchor (LMA) serves as a gateway. The LMA 10 assigns a Home Network Prefix (HNP) and sends it to the mobile node 18. In addition, the LMA 10 ensures connection by maintaining the address and location information of all the terminals in the domain it manages.

The authentication server 12 is an AAA server that provides authentication, authorization, and accounting. According to one aspect, the authentication server 12 manages multiple interface (MIF) information of multiple interface terminals, ie mobile nodes 18.

Hereinafter, an initial registration state of a mobile node according to an embodiment will be described with reference to FIG. 1.

First, the mobile node (MN) 18 transmits a router solicitation (RS) message including terminal identification information (MN_ID) and multiple interface (MIF) information to the mobile access gateway (MAG) 14 for initial registration.

The mobile access gateway 14 then forwards it to the authentication server 12. The authentication server 12 authenticates the mobile node 18 using the MN_ID, updates the multi-interface (MIF) information, and then transfers the information about the home network prefix (HNP) and the LMA of the mobile node 18. Forward to gateway 14.

Afterwards, the mobile access gateway 14 updates the MAT (MAG Address Translator) table and transmits a Proxy Binding Update (PBU) message to the Local Mobility Anchor (LMA). Here, the MAT table manages LMA address information, link layer ID (MAC), handover indication (HI), and access technology type (ATT) of the mobile node.

The Local Mobility Anchor (LMA) then updates the Binding Cache Entry (BCE), which includes the MAG information, the Access Technology Type (ATT), and the Handover Indication (HI) information, and then the Proxy Binding to the Mobile Access Gateway 14. Transmit acknowledgment).

As a result, a bi-directional tunnel is formed between the mobile access gateway 14 and the LMA 10, and data communication between the mobile node 18 and the counterpart node 19 is possible through the formed bidirectional tunnel.

  2 is a reference diagram for explaining a heterogeneous network handover procedure of a multi-interface terminal according to an embodiment;

In FIG. 2, the first MAG 14a communicates with the mobile node 18 through the BSs 162a and 164a as a gateway of the WiMAX network, and the second MAG 14b communicates with the AP as a gateway of the Wi-Fi network. Communicate with mobile node 18 via 166a, 168b. If the mobile node 18 performs heterogeneous manganese handover to the second MAG 14b via the second interface IF2 while being connected to the first MAG 14a via the first interface IF1, the first MAG 14a detects that the mobile node 18 has detached from its scope, and recognizes a detach event. The first MAG 14a then sends a DeReg PBU message to the LMA 10 to report that the mobile node 18 is not in its range (510). Thereafter, the LMA 10 deletes an entry related to the mobile node 18 to its binding cache entry, and transmits a PBA message to the first MAG 14a to allow the mobile node 18 to transmit the PBA message. Notify that it has been deleted. The LMA 10 then waits for a PBU message from the mobile node 18 for a period of time.

The mobile node 18 detects the second MAG 14b via the Wi-Fi interface IF2 and transmits a Router Solicitation (RS) message including MN_ID and MIF information. Subsequently, the same procedure as the terminal registration procedure described with reference to FIG. 1 is performed to register with the second MAG 14b.

After the heterogeneous network handover is performed, the second MAG 14b checks the multiple interface (MIF) information and converts the network address into an IP address including the communication interface identification information currently used by the terminal. NAT).

Specifically, in the case of a packet received from the LMA 10 and delivered to the mobile node 18 performing the handover, the IP including the communication interface identification information currently used by the terminal by checking MIF information. Perform network address translation (NAT) with (IP) addresses. When a packet is received from a multi-interface terminal performing heterogeneous network handover, the multi-interface (MIF) information is checked to perform network address translation (NAT) to an IP address including communication interface identification information previously used by the terminal. do.

3 is a flowchart of a method of performing network address translation in a mobile access gateway (MAG) according to an embodiment.

First, the MAG checks whether the received packet is received from the LMA (300). If the packet is received from the LMA, decapsulation is performed (302). In step 304, the HI field is checked in the MAT table to confirm whether the packet is received from a mobile node that has performed handover between heterogeneous networks. In one embodiment, the HI field includes information on a handover performance record of the terminal. If it is determined that the packet is a packet received from a terminal that has performed handover between heterogeneous networks (306), the multi-interface (MIF) information of the terminal is checked (308), and the IP configured using the current communication interface ID information is used. Network address translation (NAT) is performed to the address (310). The IP address-transformed packet is forwarded to the mobile node (312). The packet received from the terminal that has not performed the heterogeneous network handover is directly transmitted to the mobile node (MM).

On the other hand, if the incoming packet is a packet received from the mobile node, by checking the contents of the HI field of the MAT table (350) and determines whether the handover between heterogeneous networks (352). In the case of a packet received from a terminal that has performed heterogeneous network handover, the terminal checks MIF information of the terminal (354), and performs network address translation (NAT) to an IP address utilizing the previously used communication interface ID information. (356). Thereafter, the LMA information is identified through the LMAA checking process for the packet whose address has been converted (358), and encapsulation is performed (360). The packet is then forwarded to the LMA (362).

Accordingly, even if the counterpart terminal does not know that the IP address of the mobile node has been changed, the packet may be transmitted using the previously used IP address, and the packet may be delivered to the MAG performed by the LMA based on BCE information. Since the MAG that has performed the handover knows that the mobile node has performed the handover between heterogeneous access networks, it is possible to continuously deliver the packet even with the IP address configured with the previously used interface ID.

4 is a flowchart of a terminal initial registration and access procedure according to an embodiment. The initial access procedure follows the access procedure in the existing PMIPv6. However, there is a difference in that multiple interface (MIF) information of the mobile node MN is registered in the authentication server 12.

Referring to FIG. 4, the UE initial registration process will be described in more detail. The mobile node MN 18 transmits a router solicitation (RS) message including MN_ID and MIF information to the mobile access gateway MAG 14. Send (400). MN_ID is stable identifier information of a mobile node that can be acquired and authenticated in the PMIPv6 domain. In one embodiment, the MN_ID includes Network Access Identifier (NAI) or Media Access Control (MAC) address information.

The mobile access gateway 14 then forwards this to the authentication server 12 (410). The authentication server 12 authenticates the mobile node 18 using the MN_ID, updates the MIF information (413), and then transfers information about the HNP (Home Network Prefix) and the LMA of the mobile node 18 to the mobile access gateway. (415). At this time, the MIF information includes interface information such as WiMAX and Wi-Fi.

Thereafter, the mobile access gateway 14 updates the MAT (MAG Address Translator) table (420), and transmits a Proxy Binding Update (PBU) message to a local mobility anchor (LMA) (430). The MAT table includes LMA address information, link layer ID (MAC), handover indication (HI), and access technology type (ATT) of the mobile node. The LMA address information (LMAA) is a global address of the LMA 10 used to establish a bidirectional tunnel between the LMA 10 and the mobile access gateway 14, and is used when the mobile access gateway 14 sends a PBU message.

The LMA 14 transmits an AAA query message including MN_ID information and MIF information to the authentication server 12 (440) and receives the response (445). The Local Mobility Anchor (LMA) updates a binding cache entry (BCE) including MAG information, access technology type (ATT), and handover indication (HI) information (450), and then the PBA (mobile access gateway 14). The Proxy Binding Acknowledge is transmitted (460).

As a result, a bi-directional tunnel is formed between the mobile access gateway 14 and the LMA 10 (470), and data communication is possible between the mobile node 18 and the counterpart node 19 through the formed bidirectional tunnel. (480a, 480b, 480c).

5 is a flowchart of a handover process between heterogeneous access networks according to an embodiment.

Heterogeneous access networks may be WiMAX and Wi-Fi, for example. However, the present invention is not limited thereto and may be applicable to a wireless access network such as UMTS and WLAN. Assuming that the first MAG 14a is a configuration of the WiMAX network and the second MAG 14b is a configuration of the WiFi network, a process of performing a handover from WiMAX to Wi-Fi by a mobile node will be described below with reference to FIG. 5. do.

First, the mobile node 18 operates in WiMAX mode, in which case a bidirectional tunnel is formed between the first MAG 14a and the LMA 10 for data communication over WiMAX (500).

The mobile node 18 moves out of range of the first MAG 14a while moving from the first MAG 14a to the second MAG 14b while receiving service through the LMA 10. The first MAG 14a detects that the mobile node 18 has detached from its scope, and a detach event is generated. The first MAG 14a recognizes a detached event of the mobile node 18 and sends a DeReg PBU message to the LMA 10 to report that the mobile node 18 is not in its range. (510). The LMA 10 then deletes the entry for that mobile node 18 from its binding cache entry. That is, after removing the binding information and the routing state information (512), a PBA message is transmitted to the first MAG 14a to inform that the mobile node 18 has been deleted (514). . The LMA 10 then waits for a PBU message from the mobile node 18 for a period of time.

The mobile node 18 detects the second MAG 14b through the Wi-Fi interface and transmits a router solicitation (RS) message including MN_ID and MIF information (520). The second MAG 14b then forwards it to the authentication server 12 (530). The authentication server 12 authenticates the mobile node 18 using the MN_ID, updates the MIF information (532), and then transfers information on the HNP and LMA of the mobile node 18 to the second MAG 14b. Pass (534). At this time, the MIF information includes interface information such as WiMAX and Wi-Fi.

Thereafter, the second MAG 14b updates the MAT (MAG Address Translator) table (540), and transmits a Proxy Binding Update (PBU) message to the local mobility anchor (LMA) (542). Here, the MAT table manages LMA address information, link layer ID (MAC) of the mobile node 18, information on a handover indication (HI), and an access technology type (ATT).

The LMA 10 transmits (544) an AAA query message including the ID information and the MIF information of the mobile node 18 to the authentication server 12, receives the response (546), and transmits the response to the second MAG 14b. The binding cache entry (BCE) including the information on the information, the access technology type (ATT) and the handover indication (HI) is updated (550). The LMA 10 transmits a Proxy Binding Acknowledgment (PBA) to the second MAG 14b (560), and the second MAG 14b transmits a Router Advertisement including ID information of the HNP and the mobile node 18. Send a message to the mobile node 18 (570).

As a result, a bi-directional tunnel is formed between the second MAG 14b and the LMA 10 (580), and data communication is possible between the mobile node 18 and the counterpart node 19 through the formed bidirectional tunnel. (590a, 590b, 590c).

After completion of the handover, since the mobile node 18 configured the IP using the Wi-Fi interface ID, in order to continuously communicate with the counterpart node 19, the counterpart node 19 and the mobile node 18 have different interfaces. It should be noted that handover has been performed. However, in the existing PMIPv6, the mobile node 18 does not notify the counterpart node 19 that the handover has been performed. The mobile access gateway 14 manages a mobile node link layer ID (MN_LL_ID) used when configuring the IP of the mobile node 18, thereby translating network address translation (NAT) for packets passing through the mobile access gateway 14. Address Translation).

For the packet transmitted from the mobile node 18 to the counterpart node 19, the second MAG 14b converts and transmits the Wi-Fi interface ID constituting the IP of the mobile node 18 to the WiMAX interface ID. On the contrary, the packet destined for the mobile node 18 is transmitted by converting the WiMAX interface ID into the Wi-Fi interface ID. Since the translated address is used, IP does not change even when the mobile node 18 and the counterpart node 19 perform handover with heterogeneous access technology. Therefore, it is possible to continuously deliver packets using the IP address used before performing the handover.

   On the other hand, the above communication support method of the multi-interface terminal can be created by a computer program. The program may also be embodied by being stored in a computer readable media and being read and executed by a computer. The storage medium includes a magnetic recording medium, an optical recording medium and the like.

So far I looked at the preferred embodiments of the present invention. Those skilled in the art will appreciate that the present invention can be implemented in a modified form without departing from the essential features of the present invention. Therefore, the disclosed embodiments should be considered in an illustrative rather than a restrictive sense. The scope of the present invention is shown in the claims, and all differences within the scope equivalent thereto should be construed as being included in the present invention.

1 is a block diagram of a communication system of a multi-interface terminal according to an embodiment;

2 is a reference diagram for explaining a heterogeneous network handover procedure of a multi-interface terminal according to an embodiment;

3 is a flowchart of a method of performing network address translation in a mobile access gateway (MAG), according to an embodiment;

4 is a flowchart of a terminal initial registration and access procedure according to an embodiment;

5 is a flowchart of a handover process between heterogeneous access networks according to an embodiment.

Claims (10)

In the communication support method of a multi-interface terminal in a domain network using a protocol for network-based mobility management, Confirming whether the received packet is a packet transmitted / received to a mobile node which has performed heterogeneous network handover; Performing a network address translation (NAT) of the packet with reference to a mobile node address translation (MAT) table if the packet is transmitted / received to a mobile node that has performed heterogeneous network handover as a result of the checking; And And forwarding the address translated packet to the mobile node or counterpart node. The method of claim 1, The checking may be performed by referring to a mobile node address translation (MAT) table to determine whether to perform handover between heterogeneous networks according to handover indicator (HI) field information. Communication support method of the terminal. The method of claim 1, wherein prior to said identifying, Transmitting terminal identification information and multi-interface information received from the multi-interface terminal to an authentication server; Receiving multi-interface information and LMA (Local Mobility Anchor) address information for the multi-interface terminal authenticated from the authentication server; And And configuring a mobile node address translation (MAT) table by using the received information. The method of claim 1, wherein the identifying step, If the received packet is a packet received from an LMA, performing decapsulation; And Checking whether the received packet is received by the mobile node which performed the heterogeneous network handover according to the handover indicator (HI) field information by referring to a mobile node address translation (MAT) table for the received packet; Including, Performing the address translation (NAT) is performed in the mobile access gateway, characterized in that for performing the network address translation (NAT) to the IP (IP) address containing the communication interface identification information that the terminal is currently using Communication support method of the interface terminal. The method of claim 1, wherein performing network address translation (NAT) of the packet comprises: If the check result indicates that the packet is received from the mobile node that performed the handover, the network address translation (NAT) is performed by referring to a mobile node address translation (MAT) table. Performing; And Performing encapsulation on the network address-translated packet; and performing communication in the mobile access gateway. The method of claim 1, The network address translation (NAT) of the packet may be performed by a mobile access gateway, which performs network address translation (NAT) by checking MIF information of a mobile node address translation (MAT) table. Communication support method of the multi-interface terminal. The method of claim 1, The mobile node address translation (MAT) table includes Local Mobility Anchor (LMA) address information, link layer identification information of the terminal, Handover Indication (HI) field information, access technology type (ATT) information, and home network prefix. (HNP: Home Network Prefix) A method for supporting communication of a multi-interface terminal performed in a mobile access gateway, characterized in that it comprises at least one of. When a packet to a multi-interface terminal on which a Local Mobility Anchor (LMA) performs heterogeneous network handover is received, determining a mobile access gateway (MAG) information to which the terminal belongs based on Binding Cache Entry (BCE) information; Transmitting a packet to the identified Mobile Access Gateway (MAG) by the Local Mobility Anchor (LMA); Determining, by the mobile access gateway (MAG), whether the received packet is a packet transmitted to the terminal; If it is determined that the packet is transmitted to the terminal, the mobile access gateway (MAG) checks MIF information and converts a network address into an IP address including communication interface identification information currently used by the terminal. Performing NAT (NAT); And And transmitting the address-translated packet to the terminal. The method of claim 8, When a packet is received from a multi-interface terminal in which a mobile access gateway (MAG) performs a heterogeneous network handover, it checks the multi-interface (MIF) information and uses the network address as an IP address including communication interface identification information previously used by the terminal. Performing minor transform (NAT); And And transmitting the address-translated packet to a local mobility anchor (LMA). The method of claim 8, A mobile access gateway (MAG) transmitting identification information and multi-interface (MIF) information of the multi-interface terminal to an authentication server when a registration request is received from the multi-interface terminal; Updating, by the authentication server, multiple interface (MIF) information, and transmitting terminal authentication result, local mobility address (LMA) address information, and home network prefix (HNP) information to the mobile access gateway (MAG); ; And The mobile access gateway (MAG) configuring a mobile node address translation (MAT) table based on the received information; further comprising: The method of performing network address translation (NAT) may include network address translation (NAT) based on the mobile node address translation (MAT) table.

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