Delay constrained use of automatic repeat request for multi-hop communication systems

• US 20080144626A1
• Filed: 12/18/2006
• Published: 06/19/2008
• Est. Priority Date: 12/18/2006
• Status: Active Grant

• Current Assignee: III Holdings 3, LLC
• Original Assignee: Nokia Corporation
• Inventors: Doppler, Klaus, Bertinelli, Massimo
• Granted Patent: US 8,014,336 B2
• Time in Patent Office: Days
• US Class Current: 370/392
• CPC Class Codes: H04L 1/0018 based on latency requirement
• CPC Class Codes: H04L 1/18 Automatic repetition systems, e.g. Van Duuren systems
• CPC Class Codes: H04L 2001/0097 Relays
• CPC Class Codes: H04W 40/22 using selective relaying for reaching a BTS [Base Transceiver Station] or an access point
• CPC Class Codes: H04W 88/04 adapted for relaying to or from another terminal or user

Abstract

Minimization of delay due to automatic repeat requests in a multi-hop communication system can be accomplished to optimize the performance of delay-constrained applications such as voice over internet protocol (VoIP). The protocol described with relation to such embodiments can reduce the possible retransmissions to the first hop (the hop connecting a mobile node to a relay node). Thus, certain embodiments of the present invention can protect the most error-prone link while reducing the overall delay experienced by the user.

Claims

1. A relay node, comprising:

an access unit configured to communicate directly or indirectly with a user equipment;

a relay unit configured to communicate with a relay node or a mesh node; and

a processor unit configured to allow an automatic repeat request protocol for the access unit and to disable or limit the automatic repeat request protocol for the relay unit.

2. The relay node of claim 1, wherein the access unit is configured to communicate with the user equipment over a radio link.

3. The relay node of claim 1, wherein the access unit is configured to communicate with a mobile user equipment.

4. The relay node of claim 1, wherein the relay unit is configured to communicate with a relay network that comprises at least one of a second relay node, a base station, an access point, or an access gateway.

5. The relay node of claim 1, wherein the relay unit is configured to communicate with a mesh network that comprises at least one of a second relay node, a base station, an access point, or an access gateway.

6. The relay node of claim 1, wherein the processor is configured to disable or limit the automatic repeat request protocol for the relay unit selectively.

7. The relay node of claim 6, wherein the processor unit is configured to identify a quality of service for communication of the user equipment.

8. The relay node of claim 7, wherein the quality of service corresponds to at least one of voice over internet protocol traffic, video over internet protocol traffic, interactive collaboration traffic, interactive gaming traffic, or streaming traffic.

9. The relay node of claim 6, wherein the processor unit is configured to disable or limit the automatic repeat request protocol for the relay unit when communication with the user equipment meets a predetermined condition.

10. The relay node of claim 9, wherein the predetermined condition is that a user equipment desired delay is less than a predetermined threshold.

11. The relay node of claim 10, wherein the predetermined threshold is about 80 ms.

12. The relay node of claim 9, wherein the predetermined condition is that a number of expected hops between an access gateway, access point, or base station and the user equipment is greater than or equal to a predetermined number of hops.

13. The relay node of claim 12, wherein the predetermined number of hops is an integer less than or equal to five.

14. The relay node of claim 9, wherein the predetermined condition is that a timestamp on a packet indicates an existing delay that is equal to or greater than a predetermined threshold.

15. The relay node of claim 1, wherein the processor is configured, when the processor disables the automatic repeat request protocol for the relay unit, to perform at least one of

to employ intelligent routing to avoid weak links in the relay network or mesh network,

to change traffic scheduling parameters, or

to use a more robust link adaptation.

32. The relay node of claim 1, wherein the processor is configured to limit the automatic repeat request protocol for the relay unit by limiting the number of retransmissions to a number that is less than a default number of retransmissions.

33. The relay node of claim 9, wherein the predetermined condition is determined to be met by considering an overall delay requirement and subtracting an existing delay to provide a remaining delay, wherein the predetermined condition is determined to be met when the remaining delay is not predicted to be met with retransmissions set at a default level.

16. A relay node, comprising:

access means for communicating directly or indirectly with a user equipment;

relay means for communicating with a relay node or a mesh node; and

processor means for allowing an automatic repeat request protocol for the access unit and disabling or limiting the automatic repeat request protocol for the relay unit.

17. A method, comprising:

providing a relay node in direct or indirect communication with a user equipment and a relay network or a mesh network, wherein the relay network or mesh network provides access to a internet protocol backbone;

configuring the relay node to use an automatic repeat request protocol for communication with the user equipment; and

configuring the relay node not to use or to limit use of the automatic repeat request protocol for communicating with the relay network or the mesh network.

18. The method of claim 17, further comprising:

configuring the relay node to communicate with the user equipment over a radio link.

19. The method of claim 17, further comprising:

configuring the relay node to communicate with a mobile user equipment.

20. The method of claim 17, further comprising:

configuring the relay node to communicate with at least one of a second relay node, a base station, an access point, or an access gateway.

21. The method of claim 17, further comprising:

configuring the relay node to communicate with a mesh network that comprises at least one of a second relay node, a base station, an access point, or an access gateway.

22. The method of claim 17, wherein the configuring the relay node not to use or to limit use of the automatic repeat request protocol for communicating with the relay network or the mesh network is performed selectively when a predetermined condition is met.

23. The method of claim 22, further comprising:

deciding that the predetermined condition is met when a user equipment desired delay is below a predetermined threshold.

24. The method of claim 23, further comprising:

configuring the predetermined threshold to be about 80 ms.

25. The method of claim 22, further comprising:

deciding that the predetermined condition is met when an expected number of hops between an access gateway, access point, or base station is greater than or equal to a predetermined number of hops.

26. The method of claim 25, further comprising:

configuring the predetermined number of hops to be an integer value equal to or less than five.

27. The method of claim 22, further comprising:

deciding that the predetermined condition is met when a packet indicates that an existing delay is greater than or equal to a predetermined threshold.

28. The method of claim 17, further comprising:

identifying a quality of service of user equipment communication; and

determining that the predetermined condition is met when the quality of service corresponds to at least one of voice over internet protocol traffic, video over internet protocol traffic, interactive collaboration traffic, interactive gaming traffic, or streaming traffic.

29. The method of claim 17, further comprising:

when configuring the relay node not to use the automatic repeat request protocol for communicating with the relay network or the mesh network, configuring the relay node to perform at least one of

employing intelligent routing to avoid weak links in the relay network or mesh network,

changing traffic scheduling parameters, or

using a more robust link adaptation.

34. The method of claim 17, wherein the configuring the relay node to limit the automatic repeat request protocol for the relay unit comprises limiting the number of retransmissions to a number that is less than a default number of retransmissions.

35. The method of claim 22, further comprising:

considering an overall delay requirement and subtracting an existing delay to provide a remaining delay; and

determining the predetermined condition to be met when the remaining delay is not predicted to be met with retransmissions set at a default level.

30. A system, comprising:

a user equipment;

a relay network or a mesh network configured to provide access to an internet protocol backbone; and

a relay node configured to communicate directly or indirectly with the user equipment, configured to communicate with the relay network or mesh network, and configured to use an automatic repeat request protocol for communication with the user equipment and not to use or to limit use of the automatic repeat request protocol for communication with the relay network or mesh network.

31. A computer program embodied on a computer readable medium, encoding instructions for performing a method, comprising:

initiating a relay node in direct or indirect communication with a user equipment and a relay network or a mesh network, wherein the relay network or mesh network provides access to a internet protocol backbone;

configuring the relay node to use an automatic repeat request protocol for communication with the user equipment; and

configuring the relay node not to use or to limit use of the automatic repeat request protocol for communicating with the relay network or the mesh network.