Label switched packet transfer

• US 20020105922A1
• Filed: 09/20/2001
• Published: 08/08/2002
• Est. Priority Date: 09/20/2000
• Status: Active Grant

• Current Assignee: RPX Corporation
• Original Assignee: George Mason Intellectual Properties, Inc.
• Inventors: Jabbari, Bijan, Dinan, Esmael, Papneja, Rajiv
• Granted Patent: US 7,061,896 B2
• Time in Patent Office: Days
• US Class Current: 370/328
• CPC Class Codes: H04L 45/04 Interdomain routing, e.g. hierarchical routing
• CPC Class Codes: H04L 45/502 Frame based
• CPC Class Codes: H04L 69/22 Parsing or analysis of headers
• CPC Class Codes: H04W 28/065 using assembly or disassembly of packets
• CPC Class Codes: H04W 36/12 Reselecting a serving backbone network switching or routing node
• CPC Class Codes: H04W 4/06 Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services
• CPC Class Codes: H04W 40/00 Communication routing or communication path finding
• CPC Class Codes: H04W 40/02 Communication route or path selection, e.g. power-based or shortest path routing
• CPC Class Codes: H04W 40/20 based on geographic position or location
• CPC Class Codes: H04W 84/00 Network topologies
• CPC Class Codes: H04W 84/042 Public Land Mobile systems, e.g. cellular systems
• CPC Class Codes: H04W 88/08 Access point devices
• CPC Class Codes: H04W 92/20 between access points

Abstract

A method and apparatus to support a hierarchical architecture which integrates wireless mobile terminals into networks such as the Internet. This architecture provides for efficient packet transfers over mobile wireless networks by efficiently allocating wireless resources. Label Switched packet forwarding facilitates traffic engineering and internetworking by attaching short fixed length labels to communications packets at an entry node to a wireless network to provide an efficient path to an exit node of the same wireless network. Forwarding mechanisms and limited broadcasting of reachability information are used in managing and routing the communications packets through the wireless mobile network. The present invention also supports multiple radio links between a mobile and a multiplicity of base stations. Multi-link techniques are used to affect an efficient packet transfer and admission policy.

Claims

1. A cellular network comprising:

(a) a service area divided into a multitude of cells through which one or more mobile terminals can move through;

(b) base stations capable of communicating with said mobile terminals, deployed in each of said multitude of cells for forwarding packets between said base stations and said mobile terminals;

(c) a cellular label switched network, including a plurality of nodes, said plurality of nodes topologically connected, said plurality of nodes including at least one label switching node;

(d) a connection between each of said base stations and at least one label switching node for forwarding packets between said base stations and said label switching nodes;

(e) means for determining a label switched path for directing packets between a pair of locations, said locations selected from the group consisting of;

(i) nodes; and

(ii) base stations;

(f) means for attaching a label to said packets, said label including;

(i) said label switched path; and

(ii) control information;

(g) means for removing said label from said labeled packet;

(h) a means for each of said nodes to interpret said label;

(i) a means for each of said nodes to forward said label switched packet along said label switched path.

2. A cellular network according to claim 1, wherein at least one of said label switching nodes is a label edge node.

3. A cellular network according to claim 1, wherein at least one of said label switching nodes is selected from the group consisting of:

(a) a device;

(b) a switch; and

(c) a router.

4. A cellular network according to claim 1, wherein said label edge router is selected from the group consisting of:

(a) an ingress node;

(b) an egress node; and

(c) an ingress/egress node.

5. A cellular network according to claim 1, wherein said label switched nodes provide base station control information to said base stations.

6. A cellular network according to claim 1, wherein said label switched nodes concentrate traffic to said base stations.

7. A cellular network according to claim 1, wherein said label switched nodes provide support for fast handoff of said mobile terminals to said base stations.

8. A cellular network according to claim 1, wherein said label switched nodes provide location management information to said base stations.

9. A cellular network according to claim 1, further including a connection between a pair of said label switching nodes, each of said pair of label switching nodes residing in separate cellular label switched networks.

10. A cellular network according to claim 1, wherein said base stations use wireless technology to communicate with said mobile terminals.

11. A cellular network according to claim 10, wherein said wireless technology is radio technology.

12. A cellular network according to claim 10, wherein said wireless technology is optical technology.

13. A cellular network according to claim 12, wherein said optical technology is selected from the group consisting of:

(a) free space optical switching technology; and

(b) guided optical switching technology.

14. A cellular network according to claim 10, wherein said wireless technology uses a protocol layer architecture including:

(a) a wireless physical layer;

(b) a wireless medium access control protocol layer;

(c) a radio link control layer; and

(d) a network layer.

15. A cellular network according to claim 14, wherein said radio link control segments mobile packets into radio link frames identified by radio link identifiers and uses means for error mitigation to enhance poor radio link quality.

16. A cellular network according to claim 14, wherein said base station:

(a) reassembles said radio frames received from said mobile terminals into said packets;

(b) attaching said label to said packets; and

(c) forwarding said labeled packets to said label switching node.

17. A cellular network according to claim 14, wherein said base station:

(a) receives said labled packets from said label switching node;

(b) segments the said labeled packets into radio frames;

(c) removes said label from said labeled packets; and

(d) forwards said radio frames to said mobile terminal.

18. A cellular network according to claim 1, wherein said label switched path is determined by:

(a) information derived from broadcasting a network state through said network topology using a routing protocol;

(b) establishing said label switched path using a signaling protocol.

19. A cellular network according to claim 18, wherein said routing protocol is selected from the group consisting of:

(a) a link state routing protocol; and

(b) a vector space routing protocol.

20. A cellular network according to claim 1, wherein said label switched path is determined by a topology database.

21. A cellular network according to claim 1, wherein a topology database exists in a multitude of said nodes.

22. A cellular network according to claim 1, wherein a topology database is shared among its neighbor nodes.

23. A cellular network according to claim 1, further including a plurality of routing areas, each of said routing areas consisting of a set of cells whose base stations are connected to the same label switched node

24. A cellular network according to claim 23, wherein said plurality of routing areas further includes mobile terminal location information.

25. A cellular network according to claim 24, wherein said mobile terminal location information is updated whenever said mobile terminal enters one of said plurality of routing areas.

26. A cellular network according to claim 23, wherein said mobile is located by determining which of said plurality of routing areas said mobile terminal is located.

27. A cellular network according to claim 1, wherein said cellular labeled switched network is a multi-layer cellular labeled switched network.

28. A cellular network according to claim 27, wherein said cellular label switched network is divided into a plurality of smaller groups, each of said smaller groups consisting of a multiplicity of label switched nodes having topological databases.

29. A cellular network according to claim 28, wherein each of said smaller groups maintain identical topological databases.

30. A cellular network according to claim 28, wherein said topologic al databases include reachability updates.

31. A cellular network according to claim 28, wherein the topology of said smaller groups is invisible to entities outside said smaller group.

32. A cellular network according to claim 28, wherein at least one of said nodes in at least one of said smaller groups is an area border node responsible for inter-group routing.

33. A cellular network according to claim 1, wherein said cellular labeled switched network is a multitude of cellular labeled switched networks, at least one of said nodes in each of said multitude of cellular labeled switched networks is an area border node responsible for inter-cellular labeled switched network routing.

34. A cellular network according to claim 1, further including a mobile terminal hand-off mechanism including the steps of:

(a) finding a new data path from said mobile to a new base station;

(b) using said new data path to establish a new label switched path to said new base station;

(c) enabling said mobile to receive and transmit to both the old base station and the new base station when said mobile is in a diversity area;

(d) shifting the data path at a crossover node to said new label switched path; and

(e) extending traffic flow to new base station when said mobile has completely moved under said new base station'"'"'s coverage.

35. A cellular network according to claim 1, further including label merging wherein at least one of said label switched nodes is capable of:

(a) receiving two or more packets with different labels; and

(b) forwarding said two or more packets over a single outgoing interface with a singular label.

36. A cellular network according to claim 35, wherein at least two of said received packets are received through different incoming interfaces of at least one of said label switching nodes.

37. A cellular network according to claim 35, wherein said packets are received from at least one of said base stations.

38. A cellular network according to claim 1, further including at least one label switched path tunnel between a pair of said nodes along a label switched path, wherein traffic between said pair of nodes is mapped through the label switched path tunnel according to a local policy.

39. A cellular network according to claim 38, further including multiple parallel label switched path tunnels wherein at least one of said nodes is capable of establishing at least two separate label switched path tunnels to the other node.

40. A cellular network according to claim 1, wherein traffic loading is balanced on label switched paths dynamically based on local policies.

41. A cellular network according to claim 1, wherein a label switched path is rerouted by:

(a) establishing a new label switched path tunnel;

(b) transferring traffic from said label switched path to said new label switched path; and

(c) removing said label switched path.

42. A cellular network according to claim 41, wherein said label switched path and said new label switched path share resources along their common paths.

43. A cellular network according to claim 41, wherein additional messages between said base stations and said mobile are exchanged to complete handoff and cell selection process.

44. A cellular network according to claim 43, wherein cell selection process may include cell reselection.

45. A cellular network according to claim 1, wherein a label switched path is rerouted using pre-established paths and further comprising the steps of:

(a) setting a pre-established tree between the base stations located in the region of influence of the mobile and a common node prior to handoff; and

(b) selecting a different tree branch for communication when said mobile terminal moves from one of said base station to the another one of said base stations.

46. A cellular network according to claim 1, further including a handoff mechanism wherein when said mobile terminal reaches the edge of a geographical area covered by the same active tree, said mobile terminal requests a tree handoff.

47. A cellular network according to claim 1, wherein said mobile terminal receives and transmits radio packets to and from a multitude of base stations.

48. A cellular network according to claim 1, wherein a mobile terminal in a diversity area establishes packet links to a multitude of base stations capable of communicating to said mobile terminal.

49. A cellular network according to claim 1, wherein said network considers link quality when balancing traffic between the link.

50. A cellular network according to claim 1, wherein said network considers system availability when balancing link traffic.

51. A cellular network according to claim 1, further including a hand-off mechanism wherein in a pre-established path tree requires admission control of mobile connections to a tree.

52. A cellular network according to claim 51, wherein said admission control uses an overload probability value.

53. A cellular network according to claim 52, wherein determination of said overload probability value includes:

(a) the number of users;

(b) the number of base stations; and

(c) the number of connections each base station can support.