SYSTEM AND METHOD FOR MULTICAST/BROADCAST RELIABILITY ENHANCEMENT OVER WIRELESS LANs

• US 20090046613A1
• Filed: 08/15/2007
• Published: 02/19/2009
• Est. Priority Date: 08/15/2007
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Gaur, Sudhanshu
• Granted Patent: US 7,920,497 B2
• Time in Patent Office: Days
• US Class Current: 370/312
• CPC Class Codes: H04L 1/1829 Arrangements specially adapted for the receiver end
• CPC Class Codes: H04L 2001/0093 Point-to-multipoint
• CPC Class Codes: H04W 4/06 Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services

Abstract

A system comprises a communication engine for transmitting at least one groupcast packet to wireless stations on a wireless network; an ACK leader selection engine for identifying at least one of the wireless stations as a current ACK leader responsible for generating any ACK in response to the at least one groupcast packet, and for shifting the current ACK leader among a group of the wireless stations; and an ACK management engine for managing any ACK received from the current ACK leader.

Claims

1. A system comprising:

a communication engine for transmitting at least one groupcast packet to wireless stations on a wireless network;

an ACK leader selection engine for identifying at least one of the wireless stations as a current ACK leader responsible for generating any ACK in response to the at least one groupcast packet, and for shifting the current ACK leader among a group of the wireless stations; and

an ACK management engine for managing any ACK received from the current ACK leader.

2. The system of claim 1, wherein the ACK leader selection engine identifies possible ACK leaders from the wireless stations based on packet error rate metrics.

3. The system of claim 2, wherein the ACK leader selection engine identifies possible ACK leaders from the wireless station based on signal strength metrics.

4. The system of claim 1, wherein the ACK management engine instructs the communication engine to retransmit the at least one groupcast packet if no ACK is received from the ACK leader.

5. The system of claim 1, wherein the communication engine includes an identifier in the at least one groupcast packet that identifies the current ACK leader.

6. The system of claim 1, wherein the communication engine includes an ACK-active/ACK-inactive bit that identifies whether the current ACK leader is requested to respond with an ACK.

7. The system of claim 1, wherein the at least one groupcast packet includes a plurality of groupcast packets, and the ACK includes a block-ACK.

8. The system of claim 7, wherein the ACK management engine instructs the communication engine to retransmit at least the groupcast packets identified in the block-ACK as having an error.

9. The system of claim 1, wherein the group of wireless stations includes a subset of the wireless stations on the wireless network.

19. The method of claim 1, wherein the first group of wireless stations is the same as the second group of wireless stations.

10. A method comprising:

identifying at least one wireless station of a first group of wireless stations on a wireless network as a current ACK leader;

transmitting at least one groupcast packet to a second group of wireless stations on the wireless network;

managing any ACK received from the current ACK leader; and

identifying a new ACK leader within the first group of the wireless stations.

11. The method of claim 10, further comprising identifying possible ACK leaders based on packet error rate metrics.

12. The method of claim 11, further comprising identifying possible ACK leaders based on signal strength metrics.

13. The method of claim 10, further comprising retransmitting the at least one groupcast packet if no ACK is received from the ACK leader.

14. The method of claim 10, further comprising including an identifier in the at least one groupcast packet that identifies the current ACK leader.

15. The method of claim 10, further comprising including an ACK-active/ACK-inactive bit that identifies whether the current ACK leader is requested to respond with an ACK.

16. The method of claim 10, wherein the at least one groupcast packet includes a plurality of groupcast packets, and the ACK includes a block-ACK.

17. The method of claim 16, further comprising retransmitting at least the groupcast packets identified in the block-ACK as having an error.

18. The method of claim 10, wherein the first group of wireless stations includes a subset of the second group of wireless stations.

20. A method comprising:

receiving at least one groupcast packet from an access point;

determining whether the at least one groupcast packet identifies the wireless station as a current ACK leader; and

generating any ACK to the access point in response to the at least one groupcast packet received, if the at least one groupcast packet identifies the wireless station as the current ACK leader.