Service Differentiated Downlink Scheduling in Wireless Packet Data Systems

• US 20060242319A1
• Filed: 02/27/2006
• Published: 10/26/2006
• Est. Priority Date: 04/25/2005
• Status: Abandoned Application

• Current Assignee: NEC Laboratories America Inc (NEC Corporation)
• Original Assignee: NEC Laboratories America Inc (NEC Corporation)
• Inventors: Madihian, Mohammad, Wang, Xiaodong, Sang, Aimin
• Application Number:
  US11/276,379
• Publication Number:
  US 20060242319A1
• Time in Patent Office: Days
• US Class Current: 709/240
• CPC Class Codes: H04L 12/66 Arrangements for connecting between networks having differing types of switching systems, e.g. gateways

Abstract

A base station design for a wireless communication system is disclosed with a hierarchical scheduler for packet data services which is advantageously both traffic-aware and channel-dependent in a manner which enhances the users'"'"' perception of network performance. In one embodiment, a cross-layer hierarchical scheduler is disclosed which further comprises an intra-user scheduler and an inter-user scheduler.

Claims

1. A method for scheduling packets in a wireless communication system providing packet data services across a shared downlink communication channel, the method comprising the steps of:

classifying packets based on a service classification;

prioritizing the packets at an intra-user scheduler based on the service classification and on an online quality-of-service (QoS) measurement; and

prioritizing the packets at an inter-user scheduler based on results from the intra-user scheduler and based on channel conditions, as fed back by user stations in the wireless communication system, and the online QoS measurement.

2. The method of claim 1 wherein the packets are prioritized at the intra-user scheduler using weighted fair scheduling of the service classifications.

3. The method of claim 1 wherein the QoS measurement comprises a measurement of throughput.

4. The method of claim 1 wherein separate buffers are maintained by the intra-user scheduler for different service classifications for each user station.

5. The method of claim 1 wherein the packets are prioritized by the intra-user scheduler by maximizing a per-user utility across all classes.

6. The method of claim 1 wherein a separate buffer is maintained by the inter-user scheduler for each user station and wherein the packets are prioritized by the inter-user scheduler using weighted fair channel access for the users.

7. The method of claim 1 wherein the packets are prioritized by the inter-user scheduler by maximizing a system utility across all users.

8. The method of claim 7 wherein the utility is represented by a concave and non-decreasing function of a mean throughput of the network.

9. The method of claim 1 wherein the packet data services utilize the Transmission Control Protocol (TCP) and wherein the service classification is based on which TCP service is being used.

10. The method of claim 1 wherein different service classifications are specified using DiffServ.

11. A base station providing packet data services across a shared wireless downlink communication channel to one or more users, the base station comprising:

a classifier which arranges packets in the packet data services based on a plurality of service classifications;

a hierarchical scheduler further comprising an intra-user scheduler and an inter-user scheduler, the intra-user scheduler prioritizing the packets in the packet data service for each wireless station of a plurality of wireless stations based on the service classification and on a quality-of-service (QoS) measurement while the inter-user scheduler prioritizes the packets in the packet data services based on results from the intra-user scheduler and based on channel conditions, as fed back by user stations in the wireless communication system, and the QoS measurement.

12. The base station of claim 11 wherein the intra-user scheduler prioritizes the packets using weighted fair scheduling of the service classifications.

13. The base station of claim 11 wherein the QoS measurement comprises a measurement of throughput.

14. The base station of claim 11 wherein the intra-user scheduler maintains separate buffers for different service classifications for each user station.

15. The base station of claim 11 wherein the intra-user scheduler prioritizes the packets by maximizing a per-user utility across all classes.

16. The base station of claim 11 wherein the inter-user scheduler maintains a separate buffer for each user station and wherein the inter-user scheduler prioritizes the packets using weighted fair channel access for the users.

17. The base station of claim 11 wherein the inter-user scheduler prioritizes the packets by maximizing a system utility across all users.

18. The base station of claim 17 wherein the utility is represented by a concave and non-decreasing function of a mean throughput of the network.

19. A method for scheduling packets in a wireless communication system providing packet data services across a shared downlink communication channel, the method comprising the steps of:

classifying packets based on a service classification;

prioritizing the packets at an intra-user scheduler using weighted fair scheduling of the service classifications and based at least in part on an online throughput measurement; and

prioritizing the packets at an inter-user scheduler based on results from the intra-user scheduler and based on channel conditions as measured by the throughput measurement.

20. The method of claim 19 wherein the packets are prioritized by the inter-user scheduler using weighted fair channel access for the users.