Multicast in point-to-point packet-switched oriented networks

• US 20040233907A1
• Filed: 05/05/2004
• Published: 11/25/2004
• Est. Priority Date: 06/27/2001
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Keller, Ralf, Lohmar, Thorsten, Hundscheidt, Frank
• Granted Patent: US 8,098,618 B2
• Time in Patent Office: Days
• US Class Current: 370/390
• CPC Class Codes: H04L 12/185 with management of multicast group membership
• CPC Class Codes: H04L 12/189 in combination with wireless systems selective distribution or broadcast in wireless communication networks H04W4/06
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 45/16 Multipoint routing
• CPC Class Codes: H04L 45/302 Route determination based on requested QoS
• CPC Class Codes: H04W 40/246 Connectivity information discovery
• CPC Class Codes: H04W 40/32 for defining a routing cluster membership
• CPC Class Codes: H04W 40/36 due to handover

Abstract

The invention relates to a method, network node, router, serving node and system for performing multicast in a point-to-point packet-switched oriented telecommunication network. The basic idea is to introduce pre-configured multicast transmission for parts of a network. This is done by creating pre-configured transport multicast group tunnels between a router and a serving node in order to transport the multicast data. Further the present invention describes the possibility of multiplexing of the multicast data streams on a pre-configured transport multicast group tunnel. In particular the invention is applicable for multicasting in networks, like UMTS with a scarce number of resources, in the IP network between the SGSN and GGSN for example on the Gn interface.

Claims

1. A method for performing a multicast transmission of multicast data streams of multicast groups in a telecommunication network having at least one router and at least one serving node handling at least one user and providing a protocol stack having an application IP layer used for performing said multicast transmission of multicast data in at least one multicast group wherein said application IP layer is located above a point-to-point-layer. wherein

said method includes the following steps

a pre-configured transport level multicast group tunnel is pre-established by means of transport layer protocol for tunnelling on the transport layer, located below the point-to-point layer, providing a point-to-multipoint connection and said tunnel is assigned to the multicast group between the router and the serving node redirecting the multicast transmission from the application IP layer to the transport layer,

the router is adapted to multiplex the multiple multicast data streams matching with the pre-configuration onto the pre-configured transport level multicast group tunnel, and

transmission of multicast data is routed over the pre-configured transport level multicast group tunnel from the router to the at least one serving node and,

the serving node is adapted to de-multiplex multicast data streams received on the pre-configured transport level multicast group tunnel and,

transmission of multicast data streams is performed from the serving node to the at least one user registered to the multicast group.

2. The method according to claim 1, wherein if there are more then one user registered to the multicast group a replication of the multicast data streams is performed in the serving node.

3. The method according to claim 2, wherein the pre-configuration of the transport level multicast group tunnel is done according to different service classes.

4. The method according to claim 3, wherein the pre-configuration considers the different geographical regions.

5. The method according to claim 4, wherein the serving node informs the router about its interest for connection or release to or from a pre-configured transport level multicast group.

6. The method according to claim 5, wherein the router administrates by means of an administration interface the serving nodes that are to be connected or released to a pre-configured transport level multicast group tunnel.

7. The method according to claim 6, wherein between the router and at least one serving node a pre-configured multicast delivery tree is created.

8. The method according to claim 7, wherein pre-configured multicast delivery tree is established by means of multicast routing protocols.

9. The method according to claim 8 wherein if multiple multicast groups belong to the same service class, multiplexing of these multiple multicast groups is performed on the same pre-configured transport level multicast group tunnel supporting said service class.

10. The method according to claim 9, wherein a data structure for the administration of the association between the pre-configured transport level multicast groups, the registered user for the multicast group and multicast address of the multicast group is either distributed within the point-to-point oriented network or centralised.

11. The method according to claim 10, wherein the data structure is administrated in the router and/or in the serving nodes.

12. The method according to claim 11, wherein the data structure includes the relation between the pre-configured transport level multicast group tunnel and the service class.

13. The method according to claim 12, wherein the serving node collects statistics about the number of multicast data packets that they relay towards users and the number of multicast data packets that they discard and according to the result a decision is taken to de-register from a pre-configured transport level multicast group.

14. The method according to claim 13, wherein the router administrates the number of the registered serving nodes.

15. The method according to claim 14, whereby in order to de-multiplex the receiving multiplexed multiple data streams on the same pre-configured transport level multicast group tunnel, the serving node administrates a list of served multicast group with the registered users.

16. The method according to claim 15, wherein in order to perform registration or de-registration of a user to or from a multicast group, the user informs the router, the router informs the serving node and an updating of the corresponding entries in the data structure is performed.

17. The method according to claim 16, whereby if in case the user changes the serving nodes, a registration of the user to the new serving node, deleting from the old serving node and update of the corresponding entries in the router are performed.

18. The method according to claim 17, wherein the transport layer protocol for tunnelling is a control signalling protocol.

19. The method according to claim 18, wherein in order to establish and release the pre-configured transport level multicast group tunnel messages of the control signalling protocol are exchanged.

20. The method according to claim 19, wherein the control signalling protocol is a GTP Protocol.

21. The method according to claim 20, wherein a GTP Tunnelling ID TID is used for de-multiplexing the multicast streams in the serving node.

22. The method according to claim 21, wherein the multicast is an IP-multicast using IP packets with IP multicast address.

23. The method according to claim 21, wherein the indication of registration to and release from a multicast group is done by means of IGMP or MLD protocol.

25. The router according to claim 23 wherein the router controls a data structure for the administration of the relation between the pre-configured transport level multicast group tunnel, the registered users for the multicast group and a multicast address of the multicast group.

24. A router adapted to perform a multicast transmission of multicast data streams of multicast groups in a telecommunication network having at least one of said router and at least one serving node handling at least one user and providing a protocol stack having an application IP layer used for performing said multicast transmission of multicast data in at least one multicast group wherein said application IP layer is situated above a point-to-point-layer, wherein

said router includes

logic for establishment of a pre-configured transport level multicast group tunnel by means of transport layer protocol for tunnelling on the transport layer, located below the point-to-point layer, providing a point-to-multipoint connection towards the serving nodes and,

logic for multiplexing of multiple multicast data streams onto the pre-configured transport level multicast group tunnel and,

logic for transport of the multicast data over the pre-configured transport multicast group tunnel to the serving nodes.

26. A serving node adapted to perform a multicast transmission of multicast data streams of multicast groups in a telecommunication network having at least one router and at least one said serving node handling at least one user and providing a protocol stack having an application IP layer used for performing said multicast transmission of multicast data in at least one multicast group wherein said application IP layer is situated above a point-to-point-layer, wherein

said serving node includes

logic for receiving multicast data streams from the router on the pre-configured transport multicast group tunnel and,

logic for administration of the pre-configured transport level multicast group tunnel and of the users registered to the corresponding multicast group and,

logic for de-multiplexing the multicast data streams multiplexed on the pre-configured transport level multicast group tunnel and,

logic for replication of the received multicast data streams among the users registered to the corresponding multicast group.

27. (Cancelled)