Reducing signaling traffic with multicasting in a wireless communication network

• US 6,738,639 B1
• Filed: 02/28/2000
• Issued: 05/18/2004
• Est. Priority Date: 02/28/2000
• Status: Expired due to Term

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Gosselin, Jean-Francois
• Primary Examiner(s): Tran, Sinh
• Assistant Examiner(s): Gelin, Jean A
• Application Number:
  US09/515,071
• Time in Patent Office: 1,541 Days
• Field of Search: 455/422, 455/426, 455/452, 455/453, 455/454, 455/458, 455/502, 455/503, 455/509, 455/515, 455/517, 455/518, 455/519, 455/524, 455/525, 370/388, 370/389, 370/390, 370/392, 370/395.3, 370/395.31, 370/395.52, 370/312, 370/328, 370/338, 370/349, 370/401
• US Class Current: 455/519
• CPC Class Codes: H04L 12/185 with management of multicast group membership
• CPC Class Codes: H04L 12/1886 with traffic restrictions for efficiency improvement, e.g. involving subnets or subdomains
• CPC Class Codes: H04L 12/189 in combination with wireless systems selective distribution or broadcast in wireless communication networks H04W4/06
• CPC Class Codes: H04W 68/08 using multi-step notification by increasing the notification area
• CPC Class Codes: H04W 68/10 using simulcast notification

Abstract

Signaling traffic communicated from a mobile switching center to a plurality of base stations is reduced by associating the plurality of base stations to form one or more multicast groups and assigning a multicast group address to each multicast group for use in multicast communications to the base stations within each multicast group. A network interface associated with each base station is configured to filter signaling traffic for multicast messages addressed to the multicast group to which the base station belongs. If the mobile switching center and the base stations are located on different subnetworks, multicast-enabled routers and/or filter switches are also configured to only route multicast messages over communication links that connect a corresponding multicast group member. The mobile switching center may then communicate a single multicast message to all base stations within a multicast group by using the multicast group'"'"'s corresponding multicast group address.

Claims

1. A method for reducing signaling traffic communicated from a mobile switching center to a plurality of base stations, the method comprising the steps of:

associating the plurality of base stations to form a multicast group for each Location Area within the mobile switching center'"'"'s Service Area

assigning a corresponding multicast group address to each of the one or more multicast groups for use in multicast communications to the plurality of base stations within the one or more multicast groups; and

communicating, in response to an incoming call to a target wireless communication device, a first paging command to the multicast group associated with a Location Area in which the target wireless communication device last updated.

2. The method of claim 1, wherein the step of associating further comprises associating the plurality of base stations to form a second multicast group for base stations within a Service Area.

3. The method of claim 1, wherein the step of associating comprises associating at least one of the plurality of base stations with two or more multicast groups.

4. The method of claim 1, wherein the step of assigning comprises assigning a Class D Internet Protocol address to each of the one or more multicast groups.

5. The method of claim 1, further comprising the step of configuring network interfaces associated with the plurality of base stations within each of the one or more multicast groups to receive multicast messages addressed to each base station'"'"'s associated multicast group.

6. The method of claim 5, wherein the step of configuring is performed in response to a signaling command from the mobile switching center informing the plurality of base stations within each of the one or more multicast groups of the corresponding multicast group address.

7. The method of claim 5, further comprising the step of configuring routers connected between the mobile switching center and the plurality of base stations to route multicast messages to the plurality of base stations within each of the one or more multicast groups.

8. The method of claim 7, wherein the step of configuring routers is performed in response to multicast group membership information received by the routers from the plurality of base stations.

9. The method of claim 7, wherein the step of configuring routers is performed in response to multicast group membership information received by the routers from the mobile switching center.

10. The method of claim 5, further comprising the step of configuring filter switches connected between the mobile switching center and the plurality of base stations to only forward multicast messages over communication links that connect a corresponding multicast group member.

11. The method of claim 1, wherein the step of associating further comprises associating the plurality of base stations to form a separate multicast group for the Service Area, and further comprising the step of:

communicating a second paging command to the separate multicast group associated with the Service Area if the first page is unsuccessful.

12. The method of claim 1, further comprising the steps of:

communicating, in response to an incoming call to a target wireless communication device, a first paging command to a base station with which the target wireless communication device last updated; and

communicating a second paging command to the multicast group associated with the Location Area in which the target wireless communication device last updated, if the first page is unsuccessful.

13. The method of claim 12, wherein the step of associating further comprises associating the plurality of base stations to form a separate multicast group for the Service Area, and further comprising the step of:

communicating a third paging command to the separate multicast group associated with the Service Area if the second page is unsuccessful.

14. A system for reducing signaling traffic communicated from a mobile switching center to a plurality of base stations, the system comprising:

a plurality of base stations associated together to form a first multicast group for base stations within a Location Area, the plurality of base stations are further associated together to form a second multicast group for base stations within a Service Area, wherein at least one of the plurality of base stations is associated with two or more multicast groups, each of the first and second multicast groups having an associated multicast group address;

a network interface associated with individual ones of the plurality of base stations for filtering signaling traffic for multicast messages addressed to the multicast group to which the network interface'"'"'s associated base station belongs; and

a mobile switching center configured to communicate the multicast messages to the plurality of base stations within the one or more multicast groups using each multicast group'"'"'s associated multicast group address.

15. The system of claim 14, wherein the plurality of base stations are associated together to form a multicast group for a cluster of neighboring base stations.

16. The system of claim 14, wherein the multicast group addresses comprise Class D Internet Protocol addresses.

17. The system of claim 14, wherein the network interfaces associated with the plurality of base stations are configured to filter for multicast messages in response to a signaling command from the mobile switching center informing the network interface'"'"'s associated base station of the multicast group'"'"'s associated multicast group address.

18. The system of claim 17, wherein one or more of the network interfaces include multicast routing capabilities.

19. The system of claim 14, further comprising multicast-enabled routers connected between the mobile switching center and the plurality of base stations for routing the multicast messages.

20. The system of claim 19, wherein the multicast-enabled routers are configured to route the multicast messages in response to multicast group membership information received by the multicast-enabled routers from the plurality of base stations.

21. The system of claim 19, wherein the multicast-enabled routers are configured to route the multicast messages in response to multicast group membership information received by the multicast-enabled routers from the mobile switching center.

22. The system of claim 14, further comprising filter switches connected between the mobile switching center and the plurality of base stations for forwarding the multicast messages only over communication links that connect a corresponding multicast group member.

23. The system of claim 14, wherein the plurality of base stations are associated together to form a multicast group for each Location Area within the mobile switching center'"'"'s Service Area, and wherein the mobile switching center, in response to an incoming call addressed to a target wireless communication device, communicates a first paging command addressed to the multicast group associated with the Location Area in which the target wireless communication device last updated.

24. The system of claim 23, wherein the plurality of base stations are associated together to form a separate multicast group for the Service Area, and wherein the mobile switching center communicates a second paging command addressed to the separate multicast group associated with the Service Area if the first page is unsuccessful.

25. The system of claim 23, wherein the mobile switching center, prior to communicating the first paging command, communications a paging command to a particular base station with which the target wireless communication device last updated.

26. An apparatus for reducing signaling traffic, the apparatus comprising:

a base station configured to be a member of a first multicast group associated with a Location Area and further configured to be a member of a second multicast group associated with a Service Area; and

a network interface coupled to the base station, the network interface configured to filter signaling traffic for multicast messages addressed to each multicast group address associated with the one or more multicast groups.

27. The apparatus of claim 26, wherein the network interface is configured to filter signaling traffic for a particular multicast group address in response to a signaling command from the mobile switching center.

28. The apparatus of claim 27, wherein the signaling command includes the particular multicast group address.

29. The apparatus of claim 26, wherein the network interface includes multicast routing functionalities.

30. A method for reducing signaling traffic communicated from a mobile switching center to a plurality of base stations, the method comprising the steps of:

receiving a communication intended for a wireless communication device; and

communicating a first paging command to a plurality of base stations associated with a Location Area using a multicast group address assigned to the plurality of base stations within the Location Area, the first paging command instructing the plurality of base stations to perform a first page for the wireless communication device; and

communicating, if the first page is unsuccessful, a second paging command to a second plurality of base stations using a second multicast group address assigned to the second plurality of base stations.

31. The method of claim 30, wherein the Location Area comprises a particular Location Area in which the wireless communication device last registered.

32. The method of claim 30, wherein the second plurality of base stations are associated with a Service Area, and wherein the second multicast group address is assigned to the second plurality of base stations within the Service Area.

33. The method of claim 32, wherein the second plurality of base stations associated with the Service Area includes the plurality of base stations associated with the Location Area.

34. The method of claim 30, wherein the second plurality of base stations are associated with a secondary Service Area, and wherein the second multicast group address is assigned to the second plurality of base stations within the secondary Service Area.

35. The method of claim 34, wherein the second plurality of base stations associated with the secondary Service Area do not include the plurality of base stations associated with the Location Area.

36. The method of claim 30, further comprising the step of sending, prior to the step of communicating the first paging command, a paging command to a particular base station with which the wireless communication device last registered.

37. The method of claim 36, wherein the step of communicating the first paging command is performed in response to the wireless communication device failing to respond to the page from the particular base station.