Quality-Based Data Scheduling

• US 20080144552A1
• Filed: 02/10/2005
• Published: 06/19/2008
• Est. Priority Date: 02/10/2005
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Larsson, Peter, Johansson, Niklas, Meyer, Michael
• Granted Patent: US 8,351,334 B2
• Time in Patent Office: Days
• US Class Current: 370/310
• CPC Class Codes: H04L 1/0026 Transmission of channel quality indication
• CPC Class Codes: H04L 1/0059 Convolutional codes
• CPC Class Codes: H04L 1/1664 the supervisory signal being transmitted together with payload signals; piggybacking
• CPC Class Codes: H04L 1/1812 Hybrid protocols; Hybrid automatic repeat request [HARQ]
• CPC Class Codes: H04L 1/1887 Scheduling and prioritising arrangements
• CPC Class Codes: H04L 2001/0097 Relays

Abstract

The present invention relates to quality-based scheduling of data in wireless networks. In this scheduling, quality information representing the degree of decodability of previously transmitted but not correctly received and not successfully decoded data packets is estimated in receiving communications nodes. This quality information is reported back to the node that transmitted the packet. The quality information will be used by the transmitting node when scheduling subsequent data transmissions. In this scheduling process, at least one of selection of: i) receiving node(s), to which a second data packet is to be forwarded; ii) a type of the data in the second packet; and/or iii) a data flow, to which the second packet belongs, is performed based on the quality information.

Claims

1. A method of forwarding data packets in a wireless network, said method comprises the steps of in a transmitting node;

receiving quality information associated with at least one unsuccessfully decoded data packet from at least one communications node of a set of multiple candidate receiving nodes, said quality information represents the degree of decodability of said at least one unsuccessfully decoded data packet at said at least one communications node;

selecting, based on said quality information, at least one receiving node from said set of multiple candidate receiving nodes; and

forwarding a data packet to said receiving node.

2. The method according to claim 1, wherein said quality information is received from said at least one receiving node.

3. The method according to claim 1, wherein said receiving step comprises the step of receiving quality information associated with said at least one unsuccessfully decoded data packet from multiple communications nodes of said set of multiple candidate receiving nodes, said quality information represents the degree of decodability of said at least one unsuccessfully decoded data packet at said multiple communications nodes.

4. The method according to claim 1, wherein said forwarded data packet comprises data that is related to data comprised in at least one packet of said at least one unsuccessfully decoded data packet.

5. The method according to claim 1, wherein said selecting step comprises jointly selecting, based on said quality information, i) said at least one receiving node and ii) at least one of:

said data packet among multiple data packets represented in a transmit queue of said transmitting node;

a type of data in said data packet; and

at least one transmit or link parameters and said step of forwarding said data packet is performed based on said selected at least one transmit or link parameter.

7. The method according to claim 5, wherein said type of data is selected as at least one of:

redundancy data; and

at least a portion of data comprised in at least one data packet of said at least one unsuccessfully decoded data packet.

11. The method according to claim 1, wherein said selecting step is performed based on i) said quality information and ii) at least one of:

information representing link performance between said transmitting node and at least one node of said at least one communications node;

routing cost associated with at least one of said transmitting node and at least one node of said at least one communications node; and

at least one quality of service parameter.

12. The method according to claim 1, wherein said at least one unsuccessfully decoded data packet has previously been forwarded by said transmitting node.

13. The method according to claim 1, wherein said quality information (represents remaining redundancy required to successfully decode said at least one unsuccessfully decoded data packet.

14. The method according to claim 1, wherein said selecting step is performed based on optimization of an objective function that comprises said quality information.

6. A method of forwarding data packets in a wireless network, said method comprises the steps of, in a transmitting node:

receiving quality information associated with at least one unsuccessfully decoded data packet from at least one communications node, said quality information represents the degree of decodability of said at least one unsuccessfully decoded data packet at said at least one communications node;

selecting, based on said quality information, a type of data in a data packet said data is related to data comprised in at least one data packet of said at least one unsuccessfully decoded data packet; and

forwarding said data packet to at least one node of said at least one communications node.

8. The method according to claim 6, wherein said selecting step comprises jointly selecting, based on said quality information, i) said type of data and ii) at least one transmit or link parameter, and said step of forwarding said data packet is performed based on said selected at least one transmit or link parameter.

9. A method of forwarding data packets in a wireless network said method comprises the steps of, in a transmitting node:

receiving quality information associated with at least one unsuccessfully decoded data packet from at least one communications node, said quality information represents the degree of decodability of said at least one unsuccessfully decoded data packet at said at least one communications node;

selecting, based on said quality information, a flow among multiple flows represented in said transmitting node;

providing a data packet from a transmit queue of said transmitting node based on said selected flow, said data packet comprises data that is related to data comprised in at least one data packet of said at least one unsuccessfully decoded data packet; and

forwarding said data packet to at least on-e node of said at least one communications node.

10. The method according to claim 9, wherein said selecting step comprises jointly selecting, based on said quality information, i) said flow and ii) at least one of:

a type of data in said data packet; and

at least one transmit or link parameter and said step of forwarding said data packet is performed based on said selected at least one transmit or link parameter.

15. A transmitting node comprising:

a receiver for receiving quality information associated with at least one unsuccessfully decoded data packet from at least one communications nodes of a set of multiple candidate receiving nodes, said quality information represents the degree of decodability of said at least one unsuccessfully decoded data packet at said at least one communications node;

means for selecting, based on said quality information, at least one receiving node from said set of multiple candidate receiving nodes; and

a transmitter for forwarding a data packet to said receiving node.

16. The node according to claim 15, wherein said quality information is received from said at least one receiving node.

17. The node according to claim 15, wherein said receiver is configured for receiving quality information associated with said at least one unsuccessfully decoded data packet from multiple communications nodes of said set of multiple candidate receiving nodes, said quality information represents the degree of decodability of said at least one unsuccessfully decoded data packet at said multiple communications nodes.

18. The node according to claim 15, wherein said forwarded data packet comprises data that is related to data comprised in at least one packet of said at least one unsuccessfully decoded data packet.

19. The node according to claim 15, wherein said selecting means is configured for jointly selecting, based on said quality information, i) said at least one receiving node and ii) at least one of:

said data packet among multiple data packets represented in a transmit queue;

a type of data in said data packet; and

at least one transmit or link parameter, and said transmitter is operated for forwarding said data packet based on said selected at least one transmit or link parameter.

24. The node according to claim 15, wherein said selecting means is configured for performing the selection based on i) said quality information and ii) at least one of:

information representing link performance between said transmitting node and at least one node of said at least one communications node;

routing cost associated with at least one of said transmitting node and at least one node of said at least one communications node; and

at least one quality of service parameter.

25. The node according to claim 15, wherein said selecting means is configured for optimization of an objective function that comprises said quality information.

20. A transmitting node comprising

a receiver for receiving quality information associated with at least one unsuccessfully decoded data packet from at least one communications node, said quality information represents the degree of decodability of said at least one unsuccessfully decoded data packet at said at least one communications node,

means for selecting, based on said quality information, a type of data in a data packet, said data is related to data comprised in at least one of said at least one unsuccessfully decoded data packet;

and

a transmitter for forwarding said data packet to at least one node of said at least one communications node.

21. The node according to claim 20, wherein said selecting means is configured for jointly selecting, based on said quality information, i) said type of data and ii) at least one transmit or link parameter and said transmitter is operated for forwarding said data packet based on said selected at least one transmit or link parameter.

22. A transmitting node comprising:

a receiver for receiving quality information associated with at least one unsuccessfully decoded data packet from at least one communications node, said quality information represents the degree of decodability of said at least one unsuccessfully decoded data packet at said at least one communications node;

means for selecting, based on said quality information, a flow among multiple flows represented in said transmitting node;

means for providing a data packet from a transmit queue of said transmitting node based on said selected flow, said data packet comprises data that is related to data comprised in at least one of said at least one unsuccessfully decoded data packet; and

a transmitter for forwarding said data packet to at least one node of said at least one communications node.

23. The node according to claim 22, wherein said selecting means is configured for jointly selecting, based on said quality information, i) said flow and ii) at least one of:

at least one quality of service parameter; and

at least one transmit or link parameter, and said transmitter is operated for forwarding said data packet based on said selected at least one transmit or link parameter.

26. A communications node comprising:

a receiver for receiving a data packet transmitted from a transmitting node and intended to a receiving node;

means for decoding said data packet;

means for generating, if said decoding means cannot successfully decode said data packet, quality information that represents the degree of decodability of said data packet, and

a transmitter for forwarding said quality information to said transmitting node.

27. The communications node according to claim 26, wherein said receiver is configured for overhearing said data packet intended to said receiving node.

28. The communications node according to claim 26, wherein said transmitter is configured for broadcasting or multicasting said quality information.