Contention-based forwarding with integrated multi-user detection capability

• US 7,464,166 B2
• Filed: 12/08/2003
• Issued: 12/09/2008
• Est. Priority Date: 04/11/2003
• Status: Expired due to Fees

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Larsson, Peter, Johansson, Niklas
• Primary Examiner(s): Follansbee; John
• Assistant Examiner(s): MADAMBA, GLENFORD J
• Application Number:
  US10/729,835
• Publication Number:
  US 20040205105A1
• Time in Patent Office: 1,828 Days
• Field of Search: 709/228, 370/254, 370/252, 370/230
• US Class Current: 709/228
• CPC Class Codes: H04B 7/2606 Arrangements for base station coverage control, e.g. by using relays in tunnels
• 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 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/15 in relation to multipoint traffic arrangements for broadcast or multicast in data networks H04L12/18
• CPC Class Codes: H04L 47/17 Interaction among intermediate nodes, e.g. hop by hop
• CPC Class Codes: H04L 47/41 by acting on aggregated flows or links
• CPC Class Codes: H04W 28/0289 Congestion control load shedding arrangements in network planning H04W16/08; performing reselection for handling the traffic H04W36/22; wireless traffic scheduling H04W72/12
• CPC Class Codes: H04W 28/10 Flow control between communication endpoints
• CPC Class Codes: H04W 8/04 Registration at HLR or HSS [Home Subscriber Server]
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A basic idea is to employ multi-user detection (MUD) at the receiver side in a multi-hop network to concurrently decode multiple packets transmitted from multiple nodes (T₁, T₂), and prioritize among the correctly decoded packets to select one or more packets suitable for forwarding, and finally reply with a packet acknowledgement (ACK) to the corresponding transmitting node for each selected packet. In this way, the design choice of MUD is exploited in the forwarding procedure. It is furthermore beneficial to exploit also the diversity enabled by the existence of multiple relay nodes (R₁, R₂, R₃). A transmitting node that transmits its data packet signal to multiple relay candidate nodes and then receives packet acknowledgements from at least two relay candidate nodes preferably performs a prioritization to select a suitable relay node. The transmitting node then transmits a forwarding order (FO) to the selected relay node, which takes on responsibility for forwarding the information to the next node.

Claims

1. A method for contention-based forwarding of information in a multi-hop network having multiple nodes, said method comprising the steps of:

at least one of a plurality of transmitting nodes transmitting its data packet signal to multiple relay candidate nodes;

receiving, in at least one receiving relay candidate node, a superposition of signals transmitted from multiple transmitting nodes;

employing multi-user detection (MUD) to decode multiple data packets from the received superposition of signals;

prioritizing among correctly decoded packets to select at least one data packet suitable for forwarding;

replying with a packet acknowledgement for each selected packet;

prioritizing among relay candidate nodes from which acknowledgements are received to select at least one suitable relay node;

transmitting a forwarding order to said at least one selected relay node instructing the selected relay node or nodes to take on responsibility for forwarding the information to a next node in the multi-hop network.

2. The method according to claim 1, wherein said packet prioritizing step comprises the step of selecting multiple data packets suitable for forwarding, and multiple packet acknowledgements are transmitted to a plurality of corresponding transmitting nodes.

3. The method according to claim 2, wherein said multiple packet acknowledgements are aggregated in a single acknowledgement message.

4. The method according to claim 1, further comprising the step of executing, in response to a forwarding order, forwarding of a corresponding selected packet.

5. The method according to claim 4, further comprising the step of said at least one receiving node replying, in response to a forwarding order, with a corresponding forwarding order acknowledgement.

6. The method according to claim 1, further comprising the step of said at least one receiving node limiting the number of selected packets.

7. The method according to claim 1, wherein said packet prioritizing step is performed based on optimization of a predetermined objective function.

8. The method according to claim 7, wherein said predetermined objective function includes information cost progress.

9. The method according to claim 1, wherein said packet prioritizing step is performed based on at least one Quality of Service (QoS) requirement.

10. The method according to claim 1, wherein said forwarding is performed based on a contention-based multiple access protocol.

11. The method according to claim 10, wherein said contention-based multiple access protocol is diversity oriented.

12. The method according to claim 11, wherein said diversity-oriented protocol is the selection diversity forwarding (SDF) protocol.

13. The method according to claim 10, wherein said contention-based multiple access protocol is an opportunistic protocol.

14. The method according to claim 1, wherein said step of prioritizing among relay candidate nodes is performed based on optimization of a predetermined objective function.

15. The method according to claim 1, wherein at least one of said multiple relay candidate nodes is implicitly addressed based on an indication that it is a neighbor of an explicitly addressed relay candidate node.

16. The method according to claim 1, further comprising the step of each transmitting node removing, in response to an acknowledgement of a previously transmitted packet, the acknowledged packet data from a data buffer in the transmitting node.

17. The method according to claim 1, wherein said multi-hop network is a broadcastlmulticast packet radio network.

18. A system for contention-based forwarding of information in a multi-hop network having multiple nodes, wherein at least one of a plurality of transmitting nodes being configured transmitting its data packet signal to multiple relay candidate nodes, said system comprising:

means for receiving, in at least one receiving relay candidate node, a superposition of signals transmitted from multiple transmitting nodes;

means for employing multi-user detection (MUD) to decode multiple data packets from the received superposition of signals;

means for prioritizing among correctly decoded packets to select at least one data packet suitable for forwarding;

means for replying with a packet acknowledgement for each selected packet;

means for prioritizing among relay candidate nodes from which acknowledgements are received to select at least one suitable relay node; and

means for transmitting a forwarding order to said at least one selected relay node instructing the selected relay node or nodes to take on responsibility for forwarding the information to a next node in the multi-hop network.

19. The system according to claim 18, wherein said packet prioritizing means is operable for selecting multiple data packets suitable for forwarding, and said replying means is operable for transmitting multiple packet acknowledgements to a plurality of corresponding transmitting nodes.

20. The system according to claim 19, wherein said replying means is operable for aggregating multiple packet acknowledgements in a single acknowledgement message.

21. The system according to claim 18, further comprising means for executing, in response to a forwarding order, forwarding of a corresponding selected packet.

22. The system according to claim 18, further comprising means for replying, in response to a forwarding order, with a corresponding forwarding order acknowledgement.

23. The system according to claim 18, further comprising means for limiting the number of selected packets.

24. The system according to claim 18, wherein said packet prioritizing means is configured to perform packet prioritization based on optimization of a predetermined objective function.

25. The system according to claim 24, wherein said predetermined objective function includes information cost progress.

26. The system according to claim 18, wherein said packet prioritizing means is configured to perform packet prioritization based on at least one Quality of Service (QoS) requirement.

27. The system according to claim 18, wherein said means for prioritizing among relay candidate nodes is configured to perform candidate node prioritization based on optimization of a predetermined objective function.

28. The system according to claim 18, wherein said at least one transmitting node further comprises means for implicitly addressing at least one of said multiple relay candidate nodes based on an indication that it is a neighbor of an explicitly addressed relay candidate node.

29. The system according to claim 18, wherein said multi-hop network is a broadcastlmulticast packet radio network.

30. A communication node in a packet radio multi-hop network, said communication node comprising electronic circuitry configured to:

receive a superposition of signals transmitted from multiple transmitting nodes;

employ multi-user detection (MUD) to decode multiple data packets from the received superposition of signals;

prioritize among correctly decoded packets to select at least one data packet suitable for forwarding;

reply with a packet acknowledgement for each selected packet; and

receive, from at least one transmitting node having transmitted its data packet signal to multiple receiving relay candidate nodes and having selected a suitable relay node based on acknowledgements from multiple relay candidate nodes, a forwarding order instructing the selected relay node to take on responsibility for forwarding the information to a next node in the multi-hop network.

31. The communication node according to claim 30, wherein said electronic circuitry is configured to select multiple data packets suitable for forwarding and transmit multiple packet acknowledgements to a plurality of corresponding transmitting nodes.

32. The communication node according to claim 31, wherein electronic circuitry is configured to aggregate multiple packet acknowledgements in a single acknowledgement message.

33. The communication node according to claim 30, wherein the electronic circuitry is configured to limit the number of selected packets.

34. The communication node according to claim 30, wherein the electronic circuitry is configured to perform packet prioritization based on optimization of a predetermined objective function.

35. The communication node according to claim 34, wherein said predetermined objective function includes information cost progress.

36. The communication node according to claim 30, wherein the electronic circuitry is configured to perform packet prioritization based on at least one Quality of Service (QoS) requirement.