METHOD OF DATA RATE ADAPTATION FOR MULTICAST COMMUNICATION

• US 20110211468A1
• Filed: 11/02/2009
• Published: 09/01/2011
• Est. Priority Date: 11/07/2008
• Status: Active Grant

• Current Assignee: Magnolia Licensing LLC (IP Edge LLC)
• Original Assignee: Thomson Licensing (Vantiva SA)
• Inventors: Zhang, Yan Feng, Cheng, Lin Xiang, Zhang, Zhi Gang, Ma, Xiao-Jun, Wang, Xian Lei
• Granted Patent: US 8,520,677 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: H04L 1/0002 by adapting the transmission rate
• CPC Class Codes: H04L 1/18 Automatic repetition systems, e.g. Van Duuren systems
• CPC Class Codes: Y02D 30/50 in wire-line communication networks, e.g. low power modes or reduced link rate

Abstract

A method to implement an adaptive multicast data rate transmission selection includes determining the lowest signal strength station in a multicast group, using signal strength as an indicator to increase data rate, and determining if the increase in data rate is viable for multicast transmission by determining frame or packet loss using the increased data rate.

Claims

1. A method comprising:

transmitting multicast data frames at a first data rate;

receiving a number of acknowledgments of successful frame reception using the first data rate;

increasing the first data rate to a second data rate for a period of time in response to the number of acknowledgements;

transmitting multicast data frames at the second data rate;

determining frame loss during the period of time; and

determining a third multicast data rate responsive to the multicast frame loss.

2. The method of claim 1, wherein transmitting multicast data frames comprises transmitting multicast data frames in a cable communication system.

3. The method of claim 1, wherein the first data rate is selected by an access point.

4. The method of claim 1, wherein the step of increasing the first data rate to a second data rate further comprises increasing the first data rate to the second data rate responsive to feedback from a multicast group.

5. The method of claim 4, wherein feedback from the multicast group comprises an increased receive signal strength indication of a reference station.

6. The method of claim 5, wherein the increased receive signal strength indication is transmitted to all stations in the multicast group using a beacon frame.

7. The method of claim 5, wherein the reference station is characterized as having a lowest receive signal strength value within the multicast group.

8. The method of claim 4, wherein feedback from the multicast group comprises receiving multiple consecutive acknowledge messages, each acknowledge message received after transmitting multicast data frames to the multicast group.

9. The method of claim 8, wherein the number of consecutive acknowledge messages exceeds a threshold value.

10. The method of claim 9, wherein the threshold value is adaptively adjusted.

11. The method of claim 8, wherein only a reference station in the multicast group sends an acknowledge message upon successful receipt of a multicast data frame.

12. The method of claim 11, wherein stations other than the reference station in the multicast group transmit a negative acknowledge message upon receiving a multicast data frame in error.

13. The method of claim 1, wherein the step of determining a third multicast data rate responsive to the multicast frame loss comprises reducing the second data rate back to the first data rate if the frame loss reaches a threshold.

14. The method of claim 1, wherein the step of determining a third multicast data rate responsive to the multicast frame loss comprises using the second data rate as a new multicast data rate if the frame loss is less than a threshold.

15. The method of claim 14, wherein the threshold is a probability threshold based upon a ratio of transmission times of the second data rate and the first data rate.

16. A method comprising:

receiving a frame having a minimum signal strength value of a reference station within a multicast group;

measuring a receive signal strength value at a station; and

transmitting the measured receive signal strength value if the measured receive signal strength value is less than the minimum signal strength value.

17. The method of claim 16, further comprising the step of:

transmitting the measured receive signal strength value if the station is the reference station and the measured receive signal strength value is greater than the minimum signal strength value.

18. The method of claim 16, further comprising the step of:

not responding to the beacon frame if the station is not the reference station and the measured receive signal strength value is greater than the minimum signal strength value.

19. The method of claim 16, wherein receiving a frame comprises receiving a beacon frame comprising the minimum signal strength value, a multicast group address, and an identification of the reference station.