KR20090054145A - Method for performing fast handover traffic based on network - Google Patents

Abstract

The present invention relates to a method for performing network-based fast handover.

The present invention handles high-speed handover in network-based proxy mobile IPv6, which is currently being prepared for standardization in the Internet Engineering Task Force, resulting in packet loss and session dropping when mobile stations move between different subnets. It provides a way to reduce this as much as possible.

The present invention can be expected to achieve the effect of realizing high-speed handover by solving handover processing, packet loss and network load problems at high speed.

PMIPv6, FPMIPv6, MIPv6, Fast Handover, IPv6, Network Based

Description

Method for performing fast handover based on network {Method for Performing Fast Handover Traffic Based on Network}

The present invention relates to a fast handover method, and more particularly, to a network-based fast IPv6 handover method.

The protocol currently used on the Internet is the Internet protocol. IP-based Internet hosts have one or more unique addresses to distinguish them from other hosts for communication. However, in the wireless environment, since the mobile station can move to another network, it is not possible to guarantee the continuous connection with the mobile station using the existing IP protocol.

In order to solve this problem, the Mobile IP Working Group has proposed a Mobile IPv6 (MIPv6) protocol to support mobility of terminals in the IPv6 network layer.

The mobile terminal supports mobility by binding the home address (HA) of the terminal to be used in the network and the new care of address (CoA) generated by the mobile network to the home agent through the mobile IPv6 protocol when moving to a new network. Receive.

However, when the mobile station hands over, there is a problem in that data packets are not received during this period because mobility detection, address configuration and verification, and registration processes are required.

In addition, the mobile IPv6 protocol has an unoptimized routing problem in which a data packet must be transmitted through a home agent until the target node receives a binding update signal from the mobile terminal.

Recently, the Internet Engineering Task Force has standardized Proxy Mobile IPv6 (PMIPv6) that can handle mobility management on a network basis instead of handling mobility management at the terminal.

In proxy mobile IPv6, a UE may move to another wireless network without being involved in handover by performing a mobile related call processing signal that the UE should perform during handover in a network agent instead of the UE.

1 is a diagram illustrating a conventional proxy mobile IPv6 handover procedure.

The proxy mobile IPv6 protocol manages arbitrary domain networks and mobile access gateways (hereinafter referred to as 'MAG') that perform mobility management on behalf of the mobile node (MN) 100 in the access router. Localized Mobility Agents (hereinafter referred to as LMAs) are newly required.

When the mobile terminal 100 moves to a new MAG (hereinafter referred to as 'NMAG') 220, an access start message is transmitted to the ID information of the mobile terminal 100 in the L2 handover process (S10). Included in the transmission to the NMAG 220 (S20).

The NMAG 220 generates an authentication request message (AAA Request) including the ID information of the mobile terminal 100 and transmits it to the authentication server (PS / AAA) 400, and the mobile terminal 100 from the authentication server 400. Profile information is obtained (S30 and S40).

Subsequently, the NMAG 220 generates an authentication completion message (Access Authentication Complete) and transmits it to the mobile terminal 100 through a new access point (New Access Point, hereinafter referred to as 'NAP') 200, and periodically the router. The advertisement message (Router Advertisment) is generated and transmitted to the mobile terminal 100 (S50 and S60). Here, the router advertisement message includes the home network prefix of each terminal to make the link currently connected by the mobile terminal 100 as the home network of the terminal.

NMAG 220 generates a proxy binding update message (Proxy Binding Update) to register the location information of the mobile terminal 100 and transmits to the LMA / HA (500) (S70). Here, the proxy binding update message includes an ID of the mobile terminal 100 and a home network prefix assigned to the mobile terminal 100.

The LMA / HA 500 checks whether there is information on the ID of the mobile terminal 100 in its binding cache entry, and generates new information on the mobile terminal 100 if there is no information.

The NMAG 220 receives a proxy binding acknowledgment message (PBAck) in response to the proxy binding update message from the LMA / HA 500 (S80). The mobile terminal 100 receives a packet transmitted from the target node 600 to the home address of the terminal through the NMAG 220 and the LMA / HA 500 (S90).

When the authentication server is located and the mobile terminal 100 moves from the current MAG network to the NMAG network, delay time occurs due to continuous handover in the network, which causes packet loss and network load. .

In order to reduce packet loss due to handover processing delay between MAG and LMA / HA 500 in proxy mobile IPv6, a fast proxy mobile IPv6 protocol has been proposed.

The high-speed proxy mobile IPv6 protocol establishes a tunnel between the MAG 320 and the NMAG 220 where it moves before the mobile terminal 100 moves to a new network so that the mobile terminal 100 tunnels the packet during the handover procedure. It is proposed to reduce packet loss.

However, the high-speed proxy mobile IPv6 protocol causes a ping-pong problem when the mobile terminal 100 frequently moves between MAGs. In this case, since tunneling occurs continuously between MAGs, even if the handover ends, the mobile terminal 100 must wait a long time to receive a packet passing between the MAGs.

Since the fast proxy mobile IPv6 protocol does not transmit binding updates to the LMA / HA 500 and exchanges only signals for tunneling between the MAGs, the mobile terminal 100 continuously moves, causing a continuous network complexity.

In addition, even if the fast proxy mobile IPv6 protocol performs binding update from the MAG to the LMA / HA 500 for routing optimization (RO), packets may be out of order due to packets being reversed to the mobile terminal 100. There was a problem.

In order to solve this problem, the present invention is to provide a network-based high-speed IPv6 handover method.

According to an aspect of the present invention, there is provided a method for performing a fast handover according to an aspect of the present invention. Generating and transmitting an Inter Access Point Protocol notification message to neighboring access points and neighboring mobile access gateways; (b) The neighboring mobile access gateways request and receive profile information of the mobile terminal from an authentication server based on ID information of the mobile terminal, generate a response message including an inter access point protocol response option, and generate the neighbor message. Transmitting to access points; And (c) after step (b), the previous mobile access gateway of the serving network to which the mobile terminal is connected generates a handover start message for tunneling establishment and transmits the message to the neighboring mobile access gateways. Receiving a handover grant message in response to the handover start message from one of the mobile access gateways to establish tunneling.

According to an aspect of the present invention, a method for performing fast handover includes: (a) when the mobile terminal receives a scanning signal from another access point, the previous mobile access gateway of the serving network to which the mobile terminal is connected is connected to an end-user. (Neighbor Discovery: ND) request message, wherein the Endi request message includes information of the previous mobile access gateway and the ID of the mobile terminal and transmits to the neighboring mobile access gateways; (b) The neighboring mobile access gateways receiving the endi request message store the information of the previous mobile access gateway and the ID of the mobile station, and generate an endi response message including their own address information to generate the previous mobile access message. Sending to an access gateway; And (c) the previous mobile access gateway buffers the packet received from the target node (CN) when receiving the endi response message, and generates a handover start message for tunneling establishment to the neighboring mobile access gateways. Transmitting and receiving a handover grant message from the neighboring mobile access gateways in response to the handover start message to establish tunneling.

By the above-described configuration, the present invention can expect the effect of realizing a handover that does not break at high speed by solving handover processing, packet loss and network load problems at high speed.

The present invention can be expected to reduce the overall network load by minimizing the participation of the terminal in the handover process when the mobile terminal moves.

The present invention can expect the effect of realizing a high-speed handover by performing a fast information exchange between neighboring access points through the IAPP in the link layer of the mobile terminal handover.

The present invention can expect the effect of reducing the packet transmission delay time through tunneling because the packet can be transmitted through the fast binding update without going directly through the home network.

The present invention can be expected to reduce the network load of the mobile terminal to enable the efficient use of wireless / wired network resources.

The present invention can reduce packet loss and increase TCP throughput that occur when performing a conventional handover.

The present invention can prevent disconnection and quality degradation of real-time data traffic services by realizing high-speed handover at the link layer.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Throughout the specification, when a part is said to "include" a certain component, it means that it can further include other components, without excluding other components unless specifically stated otherwise. In addition, the terms “… unit”, “… unit”, “module”, “block”, etc. described in the specification mean a unit that processes at least one function or operation, which is hardware or software or a combination of hardware and software. It can be implemented as.

2 is a diagram schematically showing the configuration of a network topology according to an embodiment of the present invention.

It is assumed that the mobile terminal 100 is located in a radio overlapping area of access points connected to three MAGs (NMAG1 240, NMAG2 260, NMAG3 280) in the same domain (inter access point protocol). Inter Access Point Protocol, hereinafter referred to as 'IAPP' option).

The embodiment of the present invention assumes that the mobile terminal 100, the access point, and the MAGs should be able to use the IAPP service and may be used when the mobile terminal 100 exists in a radio overlapping area of neighboring access points.

The MAG associated with the access point that was previously receiving the service is referred to as a previous MAG (Previous MAG: PMAG) 320, and the MAG associated with the target access point to be newly serviced by the mobile terminal 100 performs a handover. New MAG, hereinafter referred to as 'NMAG'.

In the fast proxy mobile IPv6 network according to the embodiment of the present invention, a message for handover is newly defined as follows.

The IAPP Add-Notify message is a message for informing the ID and MAG information of the mobile terminal 100 to neighboring access points when detecting the start of handover of the mobile terminal 100. A message sent to access points. The IAPP response message is a response message to the IAPP Add-Notify message.

The Neighbor Discovery (ND) request message is a message for transmitting information of the previous MAG 320 and ID, write time, options, etc. of the previous MAG 320 to neighboring MAGs in the current serving MAG. The endi response message is a response message to the endi request message.

The new handover initiation message (New Handover Initiation Message) is a message that transmits the address information and table information of the previous MAG (320) to establish the tunneling to neighboring MAGs in the current serving MAG. The new handover response message is a response message to the new handover start message.

The proxy binding update message receives the packet tunneled from the previous MAG 320 to the NMAG 220, and then updates the binding information of the mobile terminal 100 stored in the LMA / HA 500 to the NMAG 220 to move later. Sends a packet transmitted to the terminal 100 to the NMAG 220 without tunneling.

The fast binding update message is a message transmitted from the target NMAG 220 to the LMA / HA 500 and the CN 600 when the mobile terminal 100 moves to a neighboring subnet.

Next, a method for performing fast proxy mobile IPv6 handover using the above-described messages will be described in detail with reference to FIG. 3.

3 is a diagram illustrating a method for performing fast proxy mobile IPv6 handover according to an embodiment of the present invention.

The mobile terminal 100 is connected to a previous MAG 320 of a serving network to receive a service. When the mobile terminal 100 moves to a wireless overlapping area between the MAGs, the mobile terminal 100 moves to a neighboring new access point 1 (hereinafter referred to as 'NAP1') 230 and the mobile terminal 100. ) Generates and transmits a beacon signal including ID information and starts L2 handover (S100).

When the NAP1 230 receives the beacon signal including the ID information of the mobile terminal 100, the NAP1 230 generates an IAPP Add-Notify message to neighbor NAP2 250 and NAP3 280. (S102, S104). Here, the IAPP additional notification message includes ID information of the mobile terminal 100 and information of the MAG connected to the NAP1 230.

As shown in FIG. 4, the format of the IAPP addition notification message includes an address length, a reservation field, a MAC address, and a sequence number in a data field. Here, the reserved field includes a 1-bit D flag option 700.

The D flag option 700 is shown in Table 1 below.

The neighboring access points NAP2 250 and NAP3 280 receive the IAPP additional notification message and transmit the received NAPP additional notification message to each neighboring MAGs NMAG2 260 and NMAG3 280 (S106 and S108).

Neighbor MAGs (NMAG2 260, NMAG3 280) generates an AAA request message for requesting the profile information of the mobile terminal 100 when receiving the IAPP additional notification message, when the MAG supports the IAPP. And transmits to the AAA (Authentication, Authorization, Accounting) server (S110, S112). Subsequently, neighboring MAGs (NMAG2 260 and NMAG3 280) receive an AAA response message including profile information of the mobile terminal 100 from the AAA server (S114, S116), and the D flag 700 of the reservation field. In step S118 and S120, an IAPP response message including a response option is generated and transmitted to neighboring access points NAP1 230, NAP2 250, and NAP3 280, respectively.

Here, the profile information of the mobile terminal 100 refers to profile information of the mobile terminal 100 required in the network during handover, such as a home network prefix, an LMA address, an address configuration policy, and the like.

The neighboring access points NAP2 250 and NAP3 280 may share the information of the mobile terminal 100 by storing the profile information of the mobile terminal 100 in a neighbor cache for a predetermined time. .

In addition, neighboring MAGs (NMAG2 260 and NMAG3 280) receive an IAPP additional notification message, and if the corresponding MAG does not support IAPP, respond to the D flag 700 in the reserved field (11). Generates an IAPP response message including the transmission to the neighboring access points (NAP1 (230), NAP2 (250), NAP3 (280)) (S118, S120).

As a result, if the IAPP cannot be performed in the current network, the endi procedure is immediately performed without processing the IAPP execution procedure.

At this time, the endi procedure is used to share CoA and routing information between neighboring MAGs.

The previous MAG 320 of the serving network generates an Endi request message and transmits it to neighboring MAGs (NMAG1 240, NMAG2 260, NMAG3 280) (S122). Here, the endi request message is a message informing the neighboring MAGs of the previous MAG (320) of the information of the previous MAG (320) and the ID, life time, options, etc. of the mobile terminal 100.

The neighboring MAGs (NMAG1 240, NMAG2 260, NMAG3 280) receiving the Endi request message store the information of the previous MAG 320 in each neighbor cache and transfer their address information to the previous MAG. Send to 320.

Each neighbor cache of neighboring MAGs (NMAG1 240, NMAG2 260, NMAG3 280) stores information of the previous MAG 320 and the ID, life time, options, etc. of the mobile terminal 100. do.

When the previous MAG 320 receives an Endi response message from the neighboring MAGs (NMAG1 240, NMAG2 260, NMAG3 280) in response to the Endi request message (S124), the new MAG 320 receives a new handover start message. Through the transmission and reception of a new handover response message, the tunneling setting operation starts with all neighboring MAGs (NMAG1 240, NMAG2 260, NMAG3 280) before link down (S126 and S128).

Since proxy mobile IPv6 has a unique IP for each mobile terminal 100, the role of the handover start message and the handover response message was to remove address setting and address duplication.

 However, in the embodiment of the present invention, a new handover start message and a new handover response message are used only for establishing tunneling between MAGs.

At this time, the previous MAG 320 buffers and stores the packet transmitted from the target node 600, and forwards the mobile terminal 100 to the NMAG1 240 to be moved (S130).

When the current mobile terminal 100 moves to the NMAG1 240, the mobile terminal 100 generates an access start message including the ID information of the mobile terminal 100 and the NMAG1 240 through the neighboring NAP1 230. Transfer to (S132).

The NMAG1 240 generates an authentication request message including ID information of the mobile terminal 100, transmits the authentication request message to the authentication server 400, and transmits the profile information of the mobile terminal 100 through the authentication response message from the authentication server 400. It is obtained (S134, S136).

Thereafter, the NMAG1 240 generates an authentication completion message and transmits it to the mobile terminal 100 (S138), periodically generates a router advertisement message and transmits it to the mobile terminal 100 (S140), and simultaneously transfers the previous MAG 320 In step S142, the tunneled packets are transmitted to the mobile terminal 100.

Here, the router advertisement message includes the home network prefix of each terminal to make the link currently connected by the mobile terminal 100 as the home network of the terminal.

In this case, the NMAG1 240 generates a proxy binding update message for registration of the location information of the mobile terminal 100 and transmits the generated proxy binding update message to the LMA / HA 500 (S144). The NMAG1 240 generates a proxy binding update message for the proxy binding update message from the LMA / HA 500. In response to the proxy binding acknowledge message (PBAck) is received (S146). Here, the proxy binding update message includes an ID of the mobile terminal 100, a home network prefix assigned to the mobile terminal 100, and address information of neighbor MAGs.

From this time, the LMA / HA 500 tunnels the packet transmitted from the target node 600 to the NMAG1 240 without passing through the previous MAG 320 (S148).

If the mobile terminal 100 moves to the NMAG2 260 again, the mobile terminal 100 assigns the ID of the mobile terminal 100 to the new access point 2 through the NAP2 250 and the L2 handover process. , Hereinafter referred to as 'NAP2' (250) (S150). Subsequently, the NAP2 250 transmits the ID of the mobile terminal 100 to the NMAG2 260 connected to the NAP2 250.

The NMAG2 260 compares the ID of the mobile terminal 100 with the ID of the mobile terminal 100 stored in its own NAVER cache and the MAG information of the mobile terminal 100 without first performing an authentication process. If is present, tunneling setup is started with the NMAG1 240, and an advanced fast binding update message is generated and transmitted to the target node 600 and the LMA / HA 500 (S152 and S154). The NMAG2 260 then has the effect of supporting fast handover by receiving the advanced fast binding response message in response to the advanced fast binding update message.

The NMAG2 260 receives the packet directly from the target node 600 and transmits the packet to the mobile terminal 100 without passing through the LMA / HA 500 through the binding update to the target node 600, thereby delaying packet transmission through tunneling. This will save you time.

The embodiments of the present invention described above are not implemented only by the apparatus and / or method, but may be implemented through a program for realizing a function corresponding to the configuration of the embodiments of the present invention, a recording medium on which the program is recorded, and the like. Such implementations may be readily implemented by those skilled in the art from the description of the above-described embodiments.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

1 is a diagram illustrating a conventional proxy mobile IPv6 handover procedure.

2 is a diagram schematically showing the configuration of a network topology according to an embodiment of the present invention.

3 is a diagram illustrating a method for performing fast proxy mobile IPv6 handover according to an embodiment of the present invention.

4 is a diagram illustrating a format of an IAPP additional notification message according to an embodiment of the present invention.

Claims (8)

In the method of performing a fast handover when the mobile station is located in the wireless overlapping area of the access points, (a) the first access point receiving the beacon signal including the ID information of the mobile station generates an Inter Access Point Protocol notification message including the ID information of the mobile station to access the neighbor; Transmitting to points and neighboring mobile access gateways; (b) The neighboring mobile access gateways request and receive profile information of the mobile terminal from an authentication server based on ID information of the mobile terminal, generate a response message including an inter access point protocol response option, and generate the neighbor message. Transmitting to access points; And (c) After step (b), the previous mobile access gateway of the serving network to which the mobile terminal is connected generates a handover start message for tunneling establishment and transmits the message to the neighboring mobile access gateways. Establishing tunneling by receiving a handover grant message in response to the handover start message from mobile access gateways Method for performing a fast handover comprising a. According to claim 1, In step (b), (d) Neighbor Discovery for sharing information of the neighboring mobile access gateways and the information of the mobile terminal when the inter-access point protocol cannot be performed through the inter-access point protocol response option of the response message. ND) steps The method for performing a fast handover further comprising. The method of claim 2, In the step (d), When the mobile terminal receives a scanning signal from another access point, a previous mobile access gateway of a serving network to which the mobile terminal is connected is a Neighbor Discovery (ND) request message—The endi request message is transmitted to the previous mobile access gateway. Generating information including a mobile access gateway's information and an ID of the mobile terminal and transmitting the generated mobile access gateway to the neighboring mobile access gateways; And The neighboring mobile access gateways receiving the endi request message store the information of the previous mobile access gateway and the ID of the mobile terminal, and generate an endi response message including their own address information to the previous mobile access gateway. Sending steps Method for performing a fast handover comprising a. The method according to claim 1 or 2, After step (c), (e) buffering the packet received from the target node by the previous mobile access gateway and transmitting the buffer to the first mobile access gateway connected with the first access point; (f) when the mobile terminal moves to the first mobile access gateway, the first mobile access gateway receives profile information of the mobile terminal in association with the authentication server based on ID information of the mobile terminal and buffers the Transmitting a packet to the mobile terminal; And (g) after step (f), the first mobile access gateway generates a proxy binding update message, including information about the mobile terminal and address information about the neighboring mobile access gateways, to the home agent. Transmitting, and receiving a response message for the proxy binding update message from the home agent. The method for performing a fast handover further comprising. The method of claim 4, wherein After step (g), When the mobile station moves to the second mobile access gateway, the second mobile access gateway, which has received a beacon signal including ID information of the mobile station, is stored in the ID of the mobile station and its own neighbor cache. Comparing the ID with the ID, starting tunneling establishment with the first mobile access gateway, and performing a fast binding update with the home agent and the target node. The method for performing a fast handover further comprising. In the method of performing a fast handover when the mobile station is located in the wireless overlapping area of the access points, (a) When the mobile terminal receives a scanning signal from another access point, a previous mobile access gateway of a serving network to which the mobile terminal is connected is a Neighbor Discovery (ND) request message—the Endi request message. Generating information including the information of the previous mobile access gateway and the ID of the mobile terminal and transmitting the generated information to neighboring mobile access gateways; (b) The neighboring mobile access gateways receiving the endi request message store the information of the previous mobile access gateway and the ID of the mobile station, and generate an endi response message including their own address information to generate the previous mobile access message. Sending to an access gateway; And (c) When the previous mobile access gateway receives the endi response message, the previous mobile access gateway buffers the packet received from the target node (CN), generates a handover start message for tunneling establishment, and transmits it to the neighboring mobile access gateways. And setting up tunneling by receiving a handover grant message from the neighboring mobile access gateways in response to the handover start message. Method for performing a fast handover comprising a. The method of claim 6, After step (c), (d) the previous mobile access gateway buffering the packet received from the target node and transmitting the buffer to the first mobile access gateway to which the mobile terminal will move; (e) the first mobile access gateway receiving profile information of the mobile terminal in association with the authentication server based on ID information of the mobile terminal and transmitting the buffered packet to the mobile terminal; And (f) After step (e), the first mobile access gateway generates a proxy binding update message, including information about the mobile terminal and address information about neighboring mobile access gateways, to the home agent. Transmitting, and receiving a response message for the proxy binding update message from the home agent. The method for performing a fast handover further comprising. The method of claim 7, wherein After step (f), When the mobile station moves to the second mobile access gateway, the second mobile access gateway, which has received a beacon signal including ID information of the mobile station, is stored in the ID of the mobile station and its own neighbor cache. Comparing the ID with the ID, starting tunneling establishment with the first mobile access gateway, and performing a fast binding update with the home agent and the target node. The method for performing a fast handover further comprising.

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