KR20030063506A - Method for processing igmp message in radio mobile communication network and apparatus for preforming the same - Google Patents

Abstract

PURPOSE: A method of processing an IGMP(Internet Group Membership Protocol) message for implementing multicast in a wireless mobile communication network is provided to enable a PDSN to recognize states of mobile communication terminals as member and non-member states by a multicast host entry table including session ID numbers of the terminals, thereby reducing transmission bandwidth between the terminals and the PDSN. CONSTITUTION: A PDSN receives a multicast packet for supplying a service from a service provider(S800). The PDSN retrieves a multicast host database by a group address of the received multicast packet(S802). The PDSN decides whether a multicast host entry table having the group address of the received multicast packet exists in the multicast host database(S804). If so(S806), the PDSN copies the multicast packet, and transmits the packet to the first to the N mobile communication terminals having session ID numbers of the multicast host entry table(S808). If the entry table does not exist, the PDSN abandons the packet(S810).

Description

TECHNICAL FOR PROCESSING IGMP MESSAGE IN RADIO MOBILE COMMUNICATION NETWORK AND APPARATUS FOR PREFORMING THE SAME}

The present invention relates to a method and apparatus for processing IGMP messages for implementing multicast in a wireless mobile communication network, and more particularly, to implement multicast in a wireless mobile communication network for efficiently providing a large amount of multimedia services in real time to a plurality of mobile communication terminals. It relates to an IGMP message processing method and apparatus for.

In today's information age, there is an increasing demand to access information using computer networking services such as the Internet.

For example, certain kinds of information, such as news, economic information, and athletic scores, are appropriate for use by multiple consumers, so this kind of information can be packaged by a single producer to produce multiple May be sent to the consumer.

A typical way for a producer to send a certain amount of information to consumers is to copy the information to be sent to each consumer and copy it to each consumer.

This method of transmission is called unicasting. In the case of a large number of consumers, this method of transmission involves a large amount of processing, such as a producer having to duplicate information according to the number of consumers, and transmitting the duplicated information to each consumer. Not only is the process required, but there is also a problem of requiring a large amount of network bandwidth.

The improvement method proposed to solve the above problem is a multicast service method. The multicast service allows a service provider to transmit a single message, which is replicated at the appropriate point on the transmission path and sent to each mobile terminal that is a member of the multicast group.

To support this multicast service, each multicast router supports at least one multicast routing protocol used to exchange multicast group membership information between the various multicast routers in the network.

In addition to supporting the multicast routing protocol, it also uses the Internet Group Membership Protocol (IGMP) to manage host groups managed by multicast routers.

In general, IGMP in the network is an Internet protocol for informing host terminals whether a multicast packet is received by a host directly connected to itself, and the multicast router manages membership of host terminals by IGMP. .

The IGMP consists of a query message for knowing whether there are hosts that a multicast router wants to receive multicast packets, and a message sent from a host terminal with a multicast group address for receiving a multicast packet as a destination address.

Here, the query message is a general query that the multicast router uses to know if there are any group members on the subnet, and a specific group that is sent to see if another member exists when it receives an IGMP message from a host terminal on the subnet. It consists of a query.

On the other hand, the IGMP message sent by the host terminal to the multicast router is composed of a subscription message sent by the host terminal to join a specific group and an exit message sent to leave any group on the subnet.

The Internet Engineering Task Force (IETF) has established IGMP version 1 and version 2 in RFC 1112 and RFC 2236, respectively.

In IGMP version 1, only inquiry messages sent by multicast routers to host terminals and subscription messages sent by host terminals to multicast routers were defined. In IGMP version 2, host terminals actively join and leave groups to multicast routers. In order to enable this, a subscription and withdrawal message was added.

The multicast service in the wired network will be described with reference to the accompanying drawings.

As shown in FIG. 1, the multicast service in a wired network is a multicast router through a wired network in which the first to Nth host terminals 100-1, 100-2,..., 100 -N are physical networks. Is connected to 102.

Here, since the first to Nth host terminals 100-1, 100-2,..., 100 -N are connected to the multicast router 102 through a wired network of the same link, the multicast router 102 provides a service. The first to Nth host terminals 100-1, 100-2,..., 100 -N receiving services from the provider 104 are managed as a group.

The multicast router 102 generates a multicast packet having a group address including first to Nth host terminals 100-1, 100-2,..., 100 -N as a destination address, and generates the generated multicast. As the packet is broadcasted, the first to Nth host terminals 100-1, 100-2,..., 100 -N can simultaneously receive the multicast packets.

At this time, among the first to Nth host terminals 100-1, 100-2,..., 100 -N, a host terminal that does not belong to the group to which the service from the service provider 104 is to be provided is a multicast packet in the IP layer. Since this is discarded, the multicast packet is transmitted only to the host terminal joined to the service group.

As illustrated in FIG. 2, the multicast router 102 manages group address list information and timer information to manage the first to Nth host terminals 100-1, 100-2,..., 100 -N as a group. Has

The group address list information is group address information for a service group managed by the multicast router 102, and the timer information includes reliability variables, query intervals, query response intervals, group membership intervals, and existence of other queryers for each group. Includes information such as grasp interval, start query interval, start query count, last member query interval, last member query count, and unreported report interval.

The multicast router 102 broadcasts an inquiry message by an IGMP message to determine a host terminal to be provided with a service according to a multicast packet received from the service provider 104. 100-1,100-2, ..., 100-N) receive simultaneously.

That is, as the multicast router 102 broadcasts one query message periodically at intervals of t seconds, the first to Nth host terminals 100-1, 100-2,..., 100 -N simultaneously query messages. Receive

When the first host terminal 100-1 receives the query message from the multicast router 102, the first host terminal 100-1 sets a delay timer set to an arbitrary value and sets another host terminal, that is, the second to Nth host terminals 100-100. 2, ..., 100-N) monitors whether it sends a join message to join the multicast group.

In this case, the first host terminal 100-1 may transmit a multicast group when the second to Nth host terminals 100-2,..., 100 -N do not transmit a subscription message to the multicast router 102. The subscription message to subscribe to is transmitted to the multicast router 102.

The multicast router 102 determines which host terminal among the first to Nth host terminals 100-1, 100-2,..., 100 -N has sent a subscription message, and how many host terminals have joined the group. There is no need to know whether the host device is present or not, and only the presence or absence of a host terminal that wants to join a specific group to receive a service is required.

Therefore, if only one host terminal among the first to Nth host terminals 100-1, 100-2,..., 100 -N joining a specific group transmits a subscription message to the multicast router 102, The cast router 102 simultaneously transmits the data packet according to the received subscription message to the first to Nth host terminals 100-1, 100-2,..., 100 -N.

Subsequently, upon receiving the subscription message from the first host terminal 100-1, the multicast router 102 adds the corresponding group to which the first host terminal 100-1 belongs to the group list.

Here, in the corresponding group to which the first host terminal 100-1 belongs, the second to Nth host terminals 100-2, ..., 100-N connected to the multicast router 102 through the same link. Included.

In addition, when the multicast router 102 receives a leave message for leaving the multicast group from the first host terminal 100-1, the multicast router 102 has another member in the multicast group to which the first host terminal 100-1 belongs. Send a group-specific query message to see if they are present.

If no host terminal responds to the group specific query message, the multicast router 102 deletes the group to which the first host terminal 100-1 belongs.

As described above, the multicast service in the wired network includes the first to Nth host terminals 100-1, 100-2,..., 100-through a query and response according to an IGMP message including a subscription message and a leave message. Joining and leaving a multicast group whose members are N) is made.

Subsequently, when the multicast router 102 receives a multicast packet having the group address as the destination address from the service provider 104, the multicast router 102 broadcasts the received multicast packet by the group address to the first through the first to the first group. Simultaneously transmits to N host terminals 100-1, 100-2, ..., 100-N.

On the other hand, with the development of communication technology, a user's desire to receive a large amount of real-time multimedia services using a wireless mobile communication terminal that communicates through a wireless mobile communication network, that is, a mobile phone is increasing.

The following problems occur when the multicast technology in a wired network is applied to provide a real-time multimedia service to a plurality of mobile communication terminals connected through a wireless mobile communication network.

In a wireless mobile communication network, a packet data service apparatus does not have a broadcasting function of simultaneously transmitting a multicast packet to a plurality of mobile communication terminals to receive a real-time multimedia service.

Accordingly, a packet data service apparatus in a wireless mobile communication network receives a multicast packet from a service provider and transmits a plurality of multicast packets to a plurality of mobile communication terminals through a one-to-one connection using a PPP session.

As in the multicast technology of the wired network, the packet data service device of the wireless mobile communication network also has only 300 mobile communication terminals mapped to the service group and timer information and mapped using a PPP session. The case of ten communication terminals is demonstrated as an example.

When the service provider transmits a data packet to 10 mobile communication terminals in the service group, the packet data service apparatus has only service group information and has no broadcasting function, and thus 300 for transmitting to 300 mobile communication terminals in the service group. Data packets are received from the service provider and then transmitted to the mobile communication terminals in the service group.

Therefore, the multicast service in the conventional wireless mobile communication network has a problem that the transmission bandwidth is too much between the packet data service device and the service provider.

In addition, since the packet data service apparatus of the wireless mobile communication network does not have a broadcasting function, when transmitting an inquiry message according to an IGMP message to a plurality of mobile communication terminals, the packet data service apparatus of the wireless mobile communication network is connected to 300 mobile communication terminals connected one-to-one using a PPP session. Since each query message has to be transmitted, not only the transmission bandwidth is wasted but also there is a problem that may cause an excessive load on the packet data service apparatus.

Accordingly, the present invention has been made to solve various problems of the prior art, and the present invention provides a method for managing a mobile communication terminal in a wireless mobile communication network by a multicast host entry table composed of a multicast group address and a session unique number of the mobile communication terminal. An object of the present invention is to provide a method and apparatus for processing IGMP messages for implementing multicast in a wireless mobile communication network.

Another object of the present invention is to provide an IGMP message processing method and apparatus for implementing a multicast in a wireless mobile communication network for processing a subscription and withdrawal message of a mobile communication terminal by a multicast host entry table.

It is still another object of the present invention to provide a multicast service method in a wireless mobile communication network for transmitting a multicast packet to a plurality of mobile communication terminals by means of a multicast host entry table.

1 is a diagram illustrating a multicast service apparatus in a wired network according to the prior art.

2 is a diagram illustrating group list information and timer information according to the prior art.

3 is a diagram illustrating a schematic configuration of an IGMP message processing apparatus for implementing multicast in a wireless mobile communication network according to the present invention;

4 illustrates a multicast host database in accordance with the present invention.

5 is a diagram schematically illustrating a state transition of a mobile communication terminal according to the present invention.

6 is a flowchart for performing a subscription message processing method of a PDSN in a wireless mobile communication network according to the present invention;

7 is a flow chart for performing a method of processing the withdrawal message of a PDSN in a wireless mobile communication network according to the present invention.

8 is a flowchart for performing a multicast service in a wireless mobile communication network according to the present invention.

<Description of the code for the main part>

300-1, ..., 300-N: first to Nth mobile communication terminals

302: PDSN

304: service provider

306: Multicast host database

The present invention for achieving the above object receives a service group subscription message from a plurality of mobile communication terminals connected through a wireless access network, the subscription message includes a group address of the service group, the approval message according to the subscription message Determines whether there is a multicast host entry table having a service group address in the multicast host database by the service group address in the received subscription message after transmitting the message to the mobile communication terminal. Includes the session unique number of the mobile terminal belonging to the group, if the multicast host entry table having the service group address exists, adds the session unique number of the mobile terminal to the multicast host entry table, according to the subscription message. W The mobile terminal receiving the message is characterized in that it provides a method and apparatus for processing an IMP message in a wireless mobile communication network, characterized in that the member state of the service group.

Another feature of the present invention is to add a multicast host entry table having a service group address in a subscription message if a multicast host entry table having a service group address does not exist, and add the multicast host entry table in the added multicast host entry table. The present invention provides a method and apparatus for processing an IMP message in a wireless mobile communication network, further comprising: setting a transmission path of the multicast packet according to the added multicast host entry table after adding a session unique number.

Another feature of the present invention is to receive a service group leave message from a plurality of mobile communication terminals connected through a wireless access network, the leave message including the group address of the service group, and move the acknowledgment message according to the leave message. The multicast host entry table having the service group address in the multicast host database is searched by the service group address in the received leave message after transmission to the communication terminal, and the session unique number of the mobile communication terminal that sent the leave message is retrieved. After determining whether the session unique number of the mobile terminal is the last session unique number in the multicast host entry table, and deleting the retrieved multicast host entry table, the deleted multicast host After releasing the transmission path of the multicast packet set according to the entry table, if the session unique number of the mobile terminal is not the last session unique number in the multicast host entry table, the session unique number of the mobile terminal that sent the withdrawal message is deleted. The mobile communication terminal receiving the approval message according to the withdrawal message provides an IMP message processing method and apparatus in a wireless mobile communication network characterized by being in a non-member state of a service group.

It is still another aspect of the present invention to receive a multicast packet having a service group address belonging to a plurality of mobile communication terminals as a destination address from a service provider, and to determine the service group address in the multicast host database by the service group address of the mobile communication terminal. After determining whether the multicast host entry table has a multicast host entry table, and if there is a multicast host entry table having a service group address, unicast to the mobile terminal by the session unique number of the mobile communication terminal in the multicast host entry table. The present invention provides a multicast service method and apparatus in a wireless mobile communication network.

Hereinafter, a preferred embodiment of an IGMP message processing method and apparatus for implementing multicast in a wireless mobile communication network according to the present invention will be described with reference to the accompanying drawings.

3 is a diagram illustrating a schematic configuration of an IGMP message processing apparatus for implementing multicast in a wireless mobile communication network according to the present invention, FIG. 4 is a diagram showing a multicast host database according to the present invention, and FIG. 2 is a diagram schematically illustrating a state transition of a mobile communication terminal according to the present invention.

Referring to FIG. 3, the apparatus for processing IGMP messages according to the present invention includes first to Nth mobile communication terminals 300-1,..., 300 -N connected to each other via a radio access network, and A packet data service device (hereinafter referred to as PDSN) 302 and a service provider 304 are included.

Herein, the wireless access network includes a base station, a base station controller, and a packet control function unit for wireless mobile communication between the first through Nth mobile communication terminals 300-1,..., 300 -N and the PDSN 302. Control Function).

The PDSN 302 is mapped one-to-one with the first to Nth mobile communication terminals 300-1,..., 300 -N through a Point-To-Point (PPP) session.

That is, since the PDSN 302 and the first through N-th mobile communication terminals 300-1,..., 300 -N are connected to one interface, the PDSN 302 is a service provider 304. A group receiving a service from a) and first to N-th mobile communication terminals 300-1,..., 300 -N belonging to the group are respectively managed.

In order to manage the first to N th mobile communication terminals 300-1,..., 300 -N in the wireless mobile communication network, the first to N th mobile communication terminals 300-1,. PDSN 302 has a multicast host database 306 as shown in FIG. 4 since it must be aware of the session unique number.

Here, the multicast host database 306 is a group address of a group receiving a service according to a multicast packet provided from the service provider 304 and first to Nth mobile communication terminals 300-1 belonging to the group. A multicast host entry table containing a session unique number of .., 300-N).

Referring to Fig. 4, the multicast host entry table in the multicast host database 306 is the group address G and the session identification numbers S ₁ ,..., S _N of the first to Nth mobile communication terminals in the group. ).

In addition, when a plurality of services are provided by a plurality of service providers of the PDSN 302, and a plurality of multicast groups are provided with a plurality of services, the multicast host database 306 may have a plurality of multicast groups according to the plurality of multicast groups. It is obvious to include the multicast host entry table.

The first to N th mobile communication terminals 300-1,..., 300 -N include a cellular phone, a PDA, a WAP phone, and an IMT-2000 terminal capable of wireless Internet access.

The IGMP message processing operation for the multicast implementation in the wireless mobile communication network according to the present invention configured as described above will be described.

First, an IGMP message processing operation of the PDSN 302 for service subscription of the first to Nth mobile communication terminals 300-1, ..., 300-N will be described.

The first to N th mobile communication terminals 300-1,..., 300 -N wirelessly access a subscription message for joining a service group for receiving a service according to a multicast packet from the service provider 304. Transmit to PDSN 302 via network. At this time, the subscription message includes service group address information.

Here, the first to N th mobile communication terminals 300-1 to 300 th to the N th mobile communication terminal 300-1,. Since it is clear that the mobile communication terminals 300-1, ..., 300-N are first subscribers, no query and response with the PDSN 302 is necessary to join the service group.

The PDSN 302 may receive an acknowledgment message for the subscription message received from the first to Nth mobile communication terminals 300-1,..., And 300 -N. ... 300-N).

The PDSN 302 then determines whether the service group receiving the service from the service provider 304 exists in the group in the multicast host database 306 according to the service group address information of the received subscription message.

That is, if the multicast host entry table having the service group address of the received subscription message exists in the multicast host database 306, the PDSN 302 indicates the first to N-th mobile communication terminals in the multicast host entry table. Add a session unique number of (300-1, ..., 300-N) into the service group.

On the other hand, if the multicast host entry table with the service group address according to the received subscription message does not exist in the multicast host database 306, add the multicast host entry table with the service group address of the received subscription message and The session unique number of the first to Nth mobile communication terminals 300-1,..., 300 -N is added to the added multicast host entry table.

The PDSN 302 also creates a multicast tree according to the transmission path of the multicast data packet for the added multicast host entry table using the multicast routing protocol.

For example, the first mobile communication terminal 300-1 transmits a service group subscription message to the PDSN 302 to receive a service provided by the service provider 304.

The PDSN 302 searches the multicast host database 306 to determine if there is a service group provided from the service provider 304 by the received subscription message.

That is, when the multicast host entry table having the service group address according to the subscription message exists in the multicast host database 306, the PDSN 302 may display the first mobile communication terminal 300-1 in the corresponding multicast host entry table. Add session unique number).

On the other hand, if the multicast host entry table having the service group address by the join message does not exist in the multicast host database 306, the multicast host entry table having the service group address according to the join message is added and added. The session unique number of the first mobile communication terminal 300-1 is added to the multicast host entry table.

At this time, the first to N-th mobile communication terminals 300-1,..., 300 -N that have received the approval message for the subscription message from the PDSN 302 may receive the service from the service provider 304. Become a member state within a service group.

In addition, the first to N th mobile communication terminals 300-1 to 300 to N do not receive an acknowledgment message within a predetermined time after transmitting a subscription message to join the service group to the PDSN 302. If so, the subscription message is repeatedly transmitted to the PDSN 302.

Next, an IGMP message processing operation of the PDSN 302 for leaving the service group of the first to Nth mobile communication terminals 300-1,..., And 300 -N will be described.

The first to N th mobile communication terminals 300-1,..., 300 -N transmit a withdrawal message to the PDSN 302 to withdraw from the service group receiving the service from the service provider 304. At this time, the withdrawal message includes service group address information.

Here, since the first to Nth mobile communication terminals 300-1,..., And 300 -N are connected one-to-one with the PDSN 302 through a single interface in a PPP session, the first to Nth send a withdrawal message. Since it is clear that the mobile communication terminals 300-1, ..., 300-N are the last leavers, queries and responses with the PDSN 302 are unnecessary for leaving the service group.

The PDSN 302 transmits an acknowledgment message according to the received withdrawal message to the first to N th mobile communication terminals 300-1,..., 300 -N.

Subsequently, the PDSN 302 determines whether a service group to which the first to N-th mobile communication terminals 300-1,..., 300 -N belong in the multicast host database 306 is received by the withdrawal message. do.

That is, if a multicast host entry table having a service group address in the leave message exists in the multicast host database 306, the PDSN 302 may determine the first through N-th mobile communication terminal 300 in the multicast host entry table. -1, ..., 300-N) session unique number is deleted.

At this time, the PDSN 302 is a corresponding multicast host entry table when the session unique number of the deleted first to Nth mobile communication terminals 300-1,..., 300 -N is the last session unique number of the corresponding group. Deletes the multicast tree according to the deleted multicast host entry table.

The first to N th mobile communication terminals 300-1,..., 300 -N receive the service provided by the service provider 304 in response to receiving the acknowledgment message for the withdrawal message from the PDSN 302. Become a non-member state of a service group.

In addition, the PDSN 302 may be handed off or powered off by the first through N-th mobile communication terminals 300-1, ..., 300-N to another PDSN (not shown). When the first to the N-th mobile communication terminal (300-1, ..., 300-N) is determined to receive an implicit withdrawal message from the first to the N-th mobile communication terminal (300-1, ..., 300) -N) leave the service group.

As described above, in the wireless mobile communication network according to the present invention, the first to Nth mobile communication terminals 300-1, ..., 300-N according to the IGMP message of joining and leaving the PDSN 302 are shown in FIG. As shown in Fig. 5, they are classified into member and nonmember states of the service group.

That is, as shown in Figure 5, the first to N-th mobile communication terminal (300-1, ..., 300-N) receives a grant message according to the subscription message from the PDSN (302) of the service group Becomes a member state.

In addition, the first to N-th mobile communication terminals 300-1,..., 300 -N, which are members of the service group, transmit the withdrawal message to the PDSN 302 and, accordingly, receive the acknowledgment message. It becomes a nonmember state excluded from.

Further, when the first to N-th mobile communication terminals 300-1, ..., 300-N are handed off to another PDSN or the power is turned off, the PPP session with the PDSN 302 is disconnected. The first to N th mobile communication terminals 300-1,..., And 300 -N are in a non-member state according to the implicit withdrawal.

On the other hand, the first to N-th mobile communication terminal (300-1, ..., 300-N) in the non-member state sends a subscription message to the PDSN (302), and accordingly receives the acknowledgment message accordingly member of the service group It becomes a state.

The multicast service operation for transmitting a multicast packet to the first to N th mobile communication terminals that have joined the service group to receive the service from the service provider 304 through the above process will be described.

The service provider 304 transmits a multicast packet to the PDSN 302 for providing a certain service to the first to N th mobile communication terminals 300-1 to 300 -N joining the service group. do.

Here, the multicast packet has an address of a service group to which the first to N th mobile communication terminals 300-1 to 300 -N belong.

The PDSN 302 determines whether a multicast host entry table with a group address corresponding to the destination address of the received multicast packet exists in the multicast host database 306.

Here, when the multicast host entry table having the group address corresponding to the destination address of the received multicast packet exists, the PDSN 302 duplicates the received multicast packet to form the first to first entries in the multicast host entry table. Unicast transmitted to the first to Nth mobile communication terminals 300-1, ..., 300-N by the unique session number of the N mobile communication terminals 300-1, ..., 300-N, respectively. Perform

On the other hand, if there is no multicast host entry table having a group address corresponding to the destination address of the received multicast packet, the PDSN 302 does not have a group receiving a service provided by the service provider 304. It judges that it does not and discards the received multicast packet.

A method of processing an IGMP message for implementing multicast in a wireless mobile communication network according to the present invention configured and operated as described above will be described in detail with reference to the accompanying drawings.

6 is a flowchart for performing a subscription message processing method in a wireless mobile communication network according to the present invention.

First, the PDSN 302 receives a subscription message for joining a service group for receiving a service from the service provider 304 from the first through N-th mobile communication terminals 300-1, ..., 300-N. Receive (S600).

Here, the subscription message to join the service group includes the address information of the service group and the session unique number of the first to Nth mobile communication terminals 300-1,..., 300 -N.

Subsequently, the PDSN 302 transmits an acknowledgment message according to the received subscription message to the first to Nth mobile communication terminals 300-1,..., 300 -N (S602).

At this time, the first through N-th mobile communication terminals 300-1,..., 300 -N become a member state subscribed to the service group in response to receiving the approval message from the PDSN 302.

The PDSN 302 searches the multicast host database 306 to find out whether a multicast host entry table with a service group address in the received subscription message exists (S604).

Here, the multicast host entry table in the multicast host database 306 includes a service group address and a session go number of the mobile communication terminal belonging to the service group.

If there is a multicast host entry table according to the subscription message in step S604 above (S606), the PDSN 302 determines the first through N-th mobile communication terminals in the multicast host entry table having the corresponding service group address (S606). 300-1,..., 300-N) adds a session unique number (S608).

On the other hand, if the multicast host entry table according to the subscription message does not exist, the PDSN 302 additionally generates a multicast host entry table having the service group address in the subscription message in the multicast host database 306 (S610). .

Subsequently, the PDSN 302 adds the session unique number of the first to Nth mobile communication terminals 300-1, ..., 300-N to the additionally generated multicast host entry table (S612). A multicast tree, which is a transmission path of a multicast packet, is generated using a routing protocol (S614).

7 is a flowchart illustrating a method of processing a withdrawal message in a wireless mobile communication network according to the present invention.

First, the PDSN 302 receives a withdrawal message from the first to Nth mobile communication terminals 300-1,. (S700).

Here, the withdrawal message includes service group address information and a session unique number of the first to Nth mobile communication terminals 300-1,..., 300 -N.

Subsequently, the PDSN 302 transmits an acknowledgment message according to the received withdrawal message to the first to Nth mobile communication terminals 300-1,..., 300 -N (S702).

In this case, the first to N-th mobile communication terminals 300-1,..., And 300 -N receive a non-member state from the service group upon receiving the approval message from the PDSN 302.

The PDSN 302 searches the multicast host database 306 to search the multicast host entry table having the service group address of the received leave message (S704).

Then, the PDSN 302 determines whether the first through Nth mobile communication terminals 300-1, ..., 300-N session unique number in the withdrawal message are the last session unique number in the retrieved multicast host entry table. (S706).

The session unique number of the first to Nth mobile communication terminals 300-1,..., 300 -N included in the withdrawal message in step S706 is the last session unique number in the retrieved multicast host entry table. If (S708), the searched multicast host entry table is deleted (S710), and the corresponding multicast tree is also removed (S712).

On the other hand, if the session unique number of the first to N-th mobile communication terminal (300-1, ..., 300-N) included in the withdrawal message is not the last session unique number in the retrieved multicast host entry table, the withdrawal message The session unique numbers of the first to N th mobile communication terminals 300-1,..., And 300 -N included therein are deleted (S714).

PDSN 302 according to the present invention if the first to N-th mobile communication terminal (300-1, ..., 300-N) is handed off to another PDSN or when the PPP session is collapsed as the power is turned off, The first to Nth mobile communication terminals 300-1,..., 300 -N are determined to be in an implicit withdrawal state and thus the first to Nth mobile communication terminals 300-1,. Perform the withdrawal process of N).

8 is a flowchart for performing a multicast service in a wireless mobile communication network according to the present invention.

First, the PDSN 302 receives a multicast packet for providing a certain service from the service provider 304 (S800).

Here, the multicast packet includes a service group address.

The PDSN 302 then searches the multicast host database 306 by the group address of the received multicast packet (S802).

In step S802, the PDSN 302 determines whether a multicast host entry table having a group address of a multicast packet received in the multicast host database 306 exists (S804).

Here, when there is a multicast host entry table having a group address (S806), the PDSN 302 duplicates the received multicast packet to have first through N-th mobile communication having a session unique number in the multicast host entry table. It transmits to the terminal (300-1, ..., 300-N) (S808).

On the other hand, if there is no multicast host entry table with the group address, the PDSN 302 discards the received multicast packet (S810).

At this time, the PDSN 302 also deletes the multicast tree established with the service provider 304.

According to the present invention, a method and apparatus for processing an IGMP message for implementing multicast in a wireless mobile communication network includes a service group address and a multicast host entry table including a session unique number of a mobile communication terminal belonging to a service group. Recognizes the state of as a member and nonmember state of a service group.

Therefore, the present invention does not need to transmit a query message for joining and leaving the service group to the mobile communication terminal, thereby reducing the transmission bandwidth between the mobile communication terminal and the PDSN, thereby providing a more efficient multimedia service. have.

In addition, the present invention does not require a response of the mobile communication terminal according to the conventional query message, there is an effect that can solve the problem that the battery of the mobile communication terminal is wasted.

In addition, since the present invention manages each mobile communication terminal belonging to a service group by using a multicast host entry table, the mobile communication terminal of the multicast host entry table after receiving one multicast packet having a service group address from a service provider. Since the multicast packet is unicasted to each mobile communication terminal by the session unique number, the transmission bandwidth between the service provider and the PDSN can be reduced.

Although the above has been described with reference to a preferred embodiment of the present invention, those skilled in the art to which the present invention pertains without departing from the spirit and scope of the present invention as set forth in the claims below It will be appreciated that modifications and variations can be made.

Claims (10)

In a method of processing an IMP message of a multicast service apparatus for transmitting a multicast packet to a plurality of mobile communication terminals connected through a wireless access network, the multicast service apparatus includes a multicast host database, and the IMP message Contains a subscription message-, Receiving a service group subscription message from the mobile communication terminal, the subscription message including a group address of the service group; Transmitting an approval message according to the subscription message to the mobile communication terminal; Determining whether a multicast host entry table having the service group address exists in a multicast host database by a service group address in the received subscription message, wherein the multicast host entry table is assigned to the service group address and the service group. A session unique number of the mobile terminal to which it belongs; Adding a session unique number of the mobile communication terminal to the multicast host entry table if the multicast host entry table having the service group address exists; Including, The mobile communication terminal receiving the approval message according to the subscription message is a member of the service group characterized in that the IMP message processing method in a wireless mobile communication network. The method of claim 1, Adding a multicast host entry table with a service group address in the subscription message if the multicast host entry table with the service group address does not exist; Adding a session unique number of the mobile communication terminal in the added multicast host entry table; Establishing a transmission path of the multicast packet according to the added multicast host entry table; IGP message processing method in a wireless mobile communication network further comprising. In a method of processing an IMP message of a multicast service apparatus for transmitting a multicast packet to a plurality of mobile communication terminals connected through a wireless access network, the multicast service apparatus includes a multicast host database, and the IMP message Contains an leave message-, Receiving a service group leave message from the mobile communication terminal, the leave message including a group address of the service group; Transmitting an approval message according to the withdrawal message to the mobile communication terminal; Retrieving a multicast host entry table having the service group address in the multicast host database by the service group address in the received leave message; Determining whether the session unique number of the mobile communication terminal that has sent the leave message is the last session unique number in the retrieved multicast host entry table; Deleting the retrieved multicast host entry table if the session unique number of the mobile communication terminal is the last session unique number in the multicast host entry table; Releasing a transmission path of the multicast packet set according to the deleted multicast host entry table; Deleting the session unique number of the mobile communication terminal that transmitted the withdrawal message if the session unique number of the mobile communication terminal is not the last session unique number in the multicast host entry table; Including, The mobile communication terminal receiving the acknowledgment message according to the withdrawal message is in a non-member state of the service group, the IMP message processing method in a wireless mobile communication network. A multicast service method of a multicast service apparatus for transmitting a multicast packet received from a service provider to a plurality of mobile communication terminals connected through a wireless access network, wherein the multicast service apparatus includes a multicast host database. , Receiving a multicast packet having a service group address to which the plurality of mobile communication terminals belong as a destination address from the service provider; Determining whether a multicast host entry table having the service group address in the multicast host database exists by the service group address of the mobile communication terminal; Unicast to the mobile communication terminal by the session unique number of the mobile communication terminal in the multicast host entry table when the multicast host entry table having the service group address exists. Multicast service method in a wireless mobile communication network comprising a. The method of claim 4, wherein Discarding the multicast packet if the multicast host entry table with the service group address does not exist Multicast service method in a wireless mobile communication network, further comprising. An IMP message processing apparatus for subscribing to service groups of a plurality of mobile communication terminals connected through a wireless access network, wherein the IGP message processing apparatus includes a multicast host database; Means for receiving a service group subscription message from the mobile communication terminal, the subscription message comprising a group address of the service group; Means for transmitting an approval message according to the subscription message to the mobile communication terminal; Means for determining whether a multicast host entry table having the service group address exists in the multicast host database by a service group address in the received subscription message, wherein the multicast host entry table includes the service group address and the service group. A session unique number of the mobile communication terminal belonging to; Means for adding a session unique number of the mobile communication terminal to the multicast host entry table if a multicast host entry table having the service group address exists; Including, The mobile communication terminal receiving the approval message according to the subscription message is an IMP message processing apparatus in a wireless mobile communication network, characterized in that the member state of the service group. The method of claim 6, Means for adding a multicast host entry table with a service group address in the subscription message if the multicast host entry table with the service group address does not exist; Means for adding a session unique number of the mobile communication terminal in the added multicast host entry table; Means for establishing a transmission path of the multicast packet according to the added multicast host entry table The IMP message processing apparatus in the wireless mobile communication network further comprising. An IMP message processing apparatus performing withdrawal of service groups of a plurality of mobile communication terminals connected through a wireless access network, wherein the IGP message processing apparatus includes a multicast host database; Means for receiving a service group leave message from the mobile communication terminal, wherein the leave message includes a group address of the service group; Means for transmitting an acknowledgment message according to the withdrawal message to the mobile communication terminal; Means for retrieving a multicast host entry table having the service group address in the multicast host database by a service group address in the received leave message; Means for determining whether the session unique number of the mobile communication terminal that sent the leave message is the last session unique number in the retrieved multicast host entry table; Means for deleting the retrieved multicast host entry table if the session unique number of the mobile communication terminal is the last session unique number in the multicast host entry table; Means for releasing a transmission path of the multicast packet set according to the deleted multicast host entry table; Means for deleting the session unique number of the mobile communication terminal that transmitted the withdrawal message if the session unique number of the mobile communication terminal is not the last session unique number in the multicast host entry table. Including, The mobile communication terminal receiving the approval message according to the withdrawal message is an IMP message processing apparatus in a wireless mobile communication network, characterized in that the non-member state of the service group. A multicast service apparatus for transmitting a multicast packet received from a service provider to a plurality of mobile communication terminals connected through a wireless access network, wherein the multicast service apparatus includes a multicast host database. Means for receiving from the service provider a multicast packet having a service group address to which the plurality of mobile communication terminals belong as a destination address; Means for determining whether a multicast host entry table having the service group address in the multicast host database exists by the service group address of the mobile communication terminal; Means for unicast to the mobile communication terminal by the session unique number of the mobile communication terminal in the multicast host entry table when the multicast host entry table having the service group address exists. Multicast service apparatus in a wireless mobile communication network comprising a. The method of claim 9, Means for discarding the multicast packet if there is no multicast host entry table with the service group address Multicast service apparatus in a wireless mobile communication network further comprising.