KR100988039B1 - Method for transmitting multicast data based on Proxy Mobile IPv6 - Google Patents

Abstract

In the PMIPv6-based multicast data transmission method proposed by the present invention, an access router receives a multicast membership query message from a multicast router, and the received multicast membership query message belongs to its own area. Transmitting to a mobile terminal; The access router receiving a multicast membership report message corresponding to the multicast membership query message and transmitting the received multicast membership report message to the multicast router; And the access router receiving the multicast data from the multicast router and transmitting the received multicast data to the mobile terminal. According to the present invention, the tunnel convergence problem between the mobile terminal and the home agent can be solved, and resource efficiency can be increased despite the increase in the number of mobile terminals.

Description

Method for transmitting multicast data based on Proxy Mobile IPv6}

The present invention relates to a multicast data transmission method, and more particularly, to a method for transmitting multicast data based on proxy mobile IP protocol (PMIPv6).

Multicast transmission is a method of transmitting data while efficiently using network bandwidth to a large number of specific users. In recent years, broadcast applications, such as broadcasting, need to transmit large media to a large number of people in a broadband network. , Video and audio streaming, video conferencing, and online gaming are attracting attention.

However, in the initial multicast transmission, the mobile terminal occupies a small portion of the components on the network, and most of the terminals were large mainframes or PCs that do not move. Today, however, various portable communication devices such as PDAs and cellular phones with data transmission functions are widely used, as well as notebooks supporting wireless networks, and wireless Internet services based on various wireless access technologies such as WLAN, 3G cellular system, and IEEE 802.16 are widely used. As it becomes more active, the necessity to support IP mobility of mobile terminals is increasing.

Mobile IPv6 (MIPv6) is used as a method for providing mobility of such a mobile terminal. However, since MIPv6 needs to manage binding information on the location information of the mobile terminal through the exchange of signaling messages between the mobile terminal and the home agent, there is a burden of mounting the MIPv6 protocol stack on the mobile terminal. On the other hand, since PMIPv6 (Proxy Moible IPv6) is a component of a network other than the mobile terminal in charge of exchanging binding-related messages instead of the mobile terminal, the mobile terminal does not need a separate protocol stack for mobility management. Accordingly, PMIPv6 may solve the problem of having a separate mobility management protocol installed in the mobile terminal, which is a disadvantage of MIPv6.

The technical problem to be achieved by the present invention is that the access router adds the MLD forwarding proxy function to the access router without adding the multicast routing function to the Mobile Access Gateway (MAG) and the Local Mobility Anchor (LMA) in the PMIPv6 domain, thereby enabling the access router to multicast membership. It is to provide a PMIPv6-based multicast data transmission method that reduces the complexity of routing by allowing the exchange of query and report messages.

In order to achieve the above object, a first aspect of the present invention provides an access router to receive a multicast membership query message from a multicast router, and sends the received multicast membership query message to its own area. Transmitting to a mobile terminal; Receiving, by the access router, a multicast membership report message corresponding to the transmitted multicast membership query message, and transmitting the received multicast membership report message to the multicast router; And receiving, by the access router, the multicast data from the multicast router, and transmitting the received multicast data to the mobile terminal.

In the present invention, since the mobile terminal exchanges a multicast membership query and report message with the multicast router using the MLD forwarding proxy function of the access router without using the MAG or LMA, the mobile terminal receives the multicast data through the access router. In addition, the tunnel convergence problem between the mobile terminal and the home agent can be solved, and resource efficiency can be increased even when the number of mobile terminals is increased.

The present invention only needs to add a function of forwarding a multicast membership query and report message to an access router, thereby enabling a simple multicasting service to be realized without modifying additional protocols or installing additional network components of the mobile terminal.

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

The PMIPv6 domain refers to a network that manages the movement of mobile terminals using PMIPv6, and requires a new component called MAG and LMA. The Mobile Access Gateway (MAG) functions to monitor the movement of the mobile terminal on the access link and transmits a mobile-related signaling message to the LMA instead of the mobile terminal. Local Mobility Anchor (LMA) serves as a home agent for mobile terminals in the PMIPv6 domain. The LMA is an anchor point on the topology of the home network allocated to the mobile terminal, and manages the reachability state of the mobile terminal in the domain. The MAG may be mounted on an access router, and the LMA may be located at a domain gateway. An IP tunnel exists between the MAG and the LMA. The IP tunnel carries a signaling message or a data packet transmitted and received between the MAG and the LMA. However, in the case of multicast data packets, multicast data packets having the same contents are delivered to a plurality of mobile terminals through separate IP tunnels, respectively, resulting in tunnel convergence problems and greatly reducing the efficiency of network resources.

However, in the present invention, the complexity of routing and tunnel convergence are possible by adding a multicast listener discovery (MLD) forwarding proxy function for forwarding multicast membership query and report messages to the access router without using such MAG and LMA. Can reduce the problem.

1 schematically illustrates a structure of a PMIPv6 based multicast data transmission system according to an embodiment of the present invention. Referring to FIG. 1, a PMIPv6-based multicast data transmission system includes a multicast router 110, a mobile terminal network anchor router 120, a previous access router 130, a new access router 140, and a mobile terminal 150. It includes. The multicast router 110, the mobile terminal network anchor router 120, the old access router 130, and the new access router 140 form the PMIPv6 domain 160, and the PMIPv6 domain 160 is connected to the network 170. It is connected.

Multicast Router (MR) 110 connects access routers 130 and 140 to a network 170, such as an IP network. The multicast router 110 is connected in a single hop with the access routers 130 and 140, exchanges a multicast membership message with the access routers 130 and 140, and access routers 130. , 140, to transmit multicast data. As an example, the multicast membership message may be a Multicast Listener Discovery (MLD) message used to exchange membership status information between an IPv6 router supporting multicasting and multicast group membership of a network segment, which is an RFC. 2710, "Multicast Listener Discovery (MLD) for IPv6". In detail, the multicast router 110 periodically transmits a multicast membership query message to the access routers 130 and 140 in order to know whether there is a mobile node 150 that has joined the multicast group. And a multicast membership report message, which is a response message thereto, from the access routers 130 and 140. After receiving the multicast membership report message, the multicast router 110 transmits multicast data to the access routers 130 and 140.

The mobile terminal network anchor router 120 (hereinafter, referred to as an anchor router) configures access routers 130 and 140 and a PMIPv6 domain (Proxy Mobile IPv6 Domain: 160). The anchor router 120 exchanges a proxy binding update (PBU) message and a proxy binding acknowledgment (PBA) message with the access routers 130 and 140 to generate a two-way IP tunnel. Exchange data packets with access routers 130 and 140 via a bidirectional IP tunnel. Specifically, when the anchor router 120 receives the proxy binding update (PBU) message from the previous access router 130, the anchor router 120 registers the previous access router 130 address with respect to the mobile terminal (MN), and the mobile terminal 150 A proxy binding acknowledgment (PBA) message including a Home Network Prefix to be assigned is sent to the legacy access router 130. At this time, the anchor router 120 generates an IP bidirectional tunnel connecting with the conventional access router 130 in order to exchange data packets with the conventional access router 130. In addition, when the anchor router 120 receives a proxy binding update (PBU) message from the new access router 130 because a handoff occurs due to the movement of the mobile terminal 150, access to the mobile terminal 150 is performed. The router address is changed from the old access router 130 address to the new access router 140 address, and a new proxy binding acknowledgment (PBA) message including a home network prefix to be assigned to the mobile terminal 150 is added. Transmit to the access router 140. The home network prefix at this time is the same as the home network prefix that was previously transmitted to the access router 130. The anchor router 120 creates an IP bidirectional tunnel connecting with the new access router 140 to exchange data packets with the new access router 140.

The conventional access router 130 connects the mobile terminal 150 to the multicast router 110 and the anchor router 120. The conventional access router 130 receives multicast data, which is data transmitted according to the multicast transmission scheme, from the multicast router 110 and transmits the multicast data to the mobile terminal 150. The conventional access router 130 receives the data transmitted according to the unicast transmission scheme from the anchor router 120, and transmits to the mobile terminal 150. In detail, the conventional access router 130 periodically receives the multicast membership query message from the multicast router 110 and transmits it to the mobile terminal 150, and receives the multicast membership report message from the mobile terminal 150. Transmit to multicast router 110. Through this, the mobile terminal 150 may receive the multicast data through the conventional access router 130. The conventional access router 130 receives the multicast data from the multicast router 110 and transmits the multicast data to the mobile terminal 150. In addition, the conventional access router 130 establishes an IP bidirectional tunnel through an anchor router 120 and a proxy binding update process, and exchanges unicast data with the anchor router 120 through the IP bidirectional tunnel. Replace it.

When the mobile terminal 150 moves to its access router area, the new access router 140 performs handoff by an L2 trigger. The handoff by the L2 trigger refers to a technique for the mobile terminal 150 to start L3 handoff with the new access router 140 in a state where the L2 connection with the previous access router 130 is not disconnected. At this time, the new access router 140 transmits a Proxy Binding Update (PBU) message including the MAC address of the mobile terminal 150 and its own address to the anchor router 120, and the PBA (Proxy) from the anchor router 120. Through the process of receiving a Binding Acknowledgment) message, a bidirectional IP tunnel is established for the anchor router 120. The new access router 140 exchanges unicast data with the anchor router 120 via this IP bidirectional tunnel. After performing the handoff, the new access router 140 receives the multicast membership query message from the multicast router 340, transmits the message to the mobile terminal 150, and sends the multicast membership report message from the mobile terminal 150. Receives and transmits to the multicast router 120. Through this, the mobile terminal 150 may receive the multicast data through the new access router 140. The new access router 140 receives the multicast data from the multicast router 120 and transmits the multicast data to the mobile terminal 150.

2 is a flowchart illustrating a PMIPv6 based multicast data transmission method according to an embodiment of the present invention.

Referring to FIG. 2, in step S210, a multicast router (MR) transmits a multicast membership query message to a mobile node (MN) via an access router (AR1). In this case, the multicast router MR and the previous access router AR1 are connected by a single hop, and the multicast router MR transmits a multicast membership query message to a mobile terminal (MN) subscribed to the multicast group. To see if there is a Mobile Node). As an example, the multicast membership query message is an MLD Query message.

In step S220, the mobile terminal MN transmits a multicast membership report message corresponding to the multicast membership query message to the multicast router MR through the previous access router AR1. As an example, the multicast membership report message is an MLD Report message. Through this, the mobile terminal MN may receive the multicast data through the multicast router MR and the conventional access router AR1.

In step S230, the multicast router MR transmits the multicast data to the mobile terminal MN via the previous access router AR1.

When the mobile terminal MN leaves the area of the previous access router AR1 and moves to the area of the new access router AR2 in step S240, the new access router AR2 is handoffed by the L2 trigger (Layer 2 Trigger). Handoff is performed to transmit a home network prefix to the mobile terminal MN. At this time, the home network prefix is the same as the home network prefix information previously transmitted to the mobile terminal MN by the access router AR2, and the mobile terminal MN may use a previously assigned home address. The handoff by the L2 trigger is a technique in which the mobile terminal MN starts the L3 handoff with the new access router AR2 in a state in which the L2 connection with the previous access router AR1 is not disconnected.

In step S250, the multicast router MR transmits a multicast membership query message to the new access router AR2, and the new access router AR2 transmits this multicast membership query message to its mobile terminal MN. do. At this time, the multicast router MR and the new access router AR1 are connected by a single hop.

In step S260, the mobile terminal MN transmits a multicast membership report message corresponding to the multicast membership query message to the new access router AR1, and the new access router AR2 sends the multicast membership report message to the multicast router. To MR. Through this, the mobile terminal MN may receive the multicast data through the multicast router MR and the new access router AR2.

In step S270, the multicast router MR transmits the multicast data to the mobile terminal MN via the new access router AR2.

FIG. 3 is a detailed flowchart of step S240 of FIG. 2.

Referring to FIG. 3, in step S310, the new access router AR2 recognizes an access of the mobile terminal MN and acquires an ID of the mobile terminal MN.

In operation S320, the new access router AR2 transmits a Proxy Binding Update (PBU) message including the acquired ID and its address to the anchor router.

In step S330 the anchor router changes the address of the access router corresponding to the mobile terminal (MN) from the address of the old access router (AR1) to the address of the new access router (AR2), the home network prefix information of the mobile terminal (MN) A PBA message is transmitted to the new access router AR2, and a bidirectional IP tunnel is created between the anchor router and the new access router AR2.

In operation S340, the new access router AR2 transmits a home network prefix to the mobile terminal MN. Through this, the mobile terminal MN may still recognize that it is in the home network, and may perform wireless communication with the new access router AR2.

The present invention can also be embodied as machine-readable code on a machine-readable recording medium such as a computer. The machine-readable recording medium includes all kinds of recording devices that store data that can be read by the machine. Examples of machine-readable recording media include ROM, RAM, CD-ROM, magnetic tape, floppy disks, optical data storage devices, and the like. In addition, the machine-readable recording medium can be distributed over several machines connected by a network so that the machine-readable code can be stored and executed in a distributed manner. In addition, functional programs, codes, and code segments for implementing the present invention can be easily inferred by programmers in the art to which the present invention belongs.

Such a method and apparatus of the present invention have been described with reference to the embodiments shown in the drawings for clarity, but these are merely exemplary, and various modifications and equivalent other embodiments are possible to those skilled in the art. Will understand. Therefore, the true technical protection scope of the present invention will be defined by the appended claims.

1 schematically illustrates a structure of a PMIPv6 based multicast data transmission system according to an embodiment of the present invention.

2 is a flowchart illustrating a PMIPv6 based multicast data transmission method according to an embodiment of the present invention.

FIG. 3 is a detailed flowchart of step S240 of FIG. 2.

Claims (3)

An access router receiving a multicast membership query message from a multicast router and transmitting the received multicast membership query message to a mobile terminal belonging to its own area; Receiving, by the access router, a multicast membership report message corresponding to the transmitted multicast membership query message, and transmitting the received multicast membership report message to the multicast router; And Receiving, by the access router, the multicast data from the multicast router, and transmitting the received multicast data to the mobile terminal. The method of claim 1, The multicast membership query message is a query message defined in the Multicast Listener Discovery (MLD) protocol. The multicast membership report message is a report message defined in the Multicast Listener Discovery (MLD) protocol. The method of claim 1, The access router is PMIPv6-based multicast data transmission method is connected to the multicast router in a single hop.

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