METHOD FOR SUPPORTING SCALABLE AND RELIABLE MULTICAST IN TDMA/TDD SYSTEMS USING FEEDBACK SUPPRESSION TECHNIQUES

• US 20080031179A1
• Filed: 10/12/2007
• Published: 02/07/2008
• Est. Priority Date: 10/28/2003
• Status: Active Grant

• Current Assignee: Fujio Watanabe, Gang Wu, Ravi Jain, Toshiro Kawahara, Xia Gao
• Original Assignee: Fujio Watanabe, Gang Wu, Ravi Jain, Toshiro Kawahara, Xia Gao
• Inventors: Jain, Ravi, Wu, Gang, Watanabe, Fujio, Kawahara, Toshiro, Gao, Xia
• Granted Patent: US 7,995,462 B2
• Time in Patent Office: Days
• US Class Current: 370/312
• CPC Class Codes: H04L 1/0057 Block codes H04L1/0061, H04L1/0064 take precedence
• CPC Class Codes: H04L 1/08 by repeating transmission, e.g. Verdan system H04L1/1858 and H04L1/189 take precedence
• CPC Class Codes: H04L 1/1621 Group acknowledgement, i.e. the acknowledgement message defining a range of identifiers, e.g. of sequence numbers
• CPC Class Codes: H04L 1/1685 the supervisory signal being transmitted in response to a specific request, e.g. to a polling signal
• CPC Class Codes: H04L 1/1819 with retransmission of additional or different redundancy
• CPC Class Codes: H04L 12/1863 comprising mechanisms for improved reliability, e.g. status reports arrangements for detecting or preventing errors by carrying supervisory signal the return channel H04L1/16
• CPC Class Codes: H04L 12/1868 Measures taken after transmission, e.g. acknowledgments
• CPC Class Codes: H04L 12/189 in combination with wireless systems selective distribution or broadcast in wireless communication networks H04W4/06
• CPC Class Codes: H04L 5/1469 using time-sharing
• CPC Class Codes: H04W 74/04 Scheduled access hybrid access H04W74/02
• CPC Class Codes: H04W 76/40 for selective distribution or broadcast
• CPC Class Codes: H04W 8/26 Network addressing or numbering for mobility support
• CPC Class Codes: H04W 84/00 Network topologies
• CPC Class Codes: H04W 84/04 Large scale networks; Deep hierarchical networks
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

A method supports scalable and reliable multicast in a wireless network with a large bandwidth-delay product. In this method, acknowledgement packets from different receivers experiencing the same number of data packets lost are assigned the same time slots. This method can be combined with other loss recovery techniques, such as forward error correction (FEC) recovery, proactive protection, feedback suppression and collision detection. Scalability is achieved as bandwidth usage relates only to the number of packets transmitted, rather than the number of receivers.

Claims

1. A media access control (MAC) module in a wireless receiver, the MAC module being interfaced to a physical layer receiver for receiving data packets and to a physical layer transmitter for sending data packets, wherein the data packets received comprise data packets of multicast messages, and wherein the data packets sent comprise acknowledgement packets, the MAC module comprising:

a detection module detecting errors in each of the data packets received;

a multicast buffer for storing the data packets received sorted according to multicast messages; and

an acknowledgement packet preparation module for preparing acknowledgement packets each indicating a specified number of data packets failed to be received into the wireless receiver.

2. A MAC module as in claim 1, wherein the specified number of data packets failed to be received is specified implicitly by transmitting an acknowledgment packet at a pre-assigned time.

3. A MAC module as in claim 1, further comprising a forward error correction (FEC) module for decoding FEC parity information in the data packets received.

4. A MAC module as in claim 1, further comprising an output queue for passing verified data packets from the error detection module for processing by an upper layer protocol.

5. A MAC module as in claim 1, further comprising an channel multiplexer for sharing the physical layer transmitter amongst data packets and the acknowledgement packets.

6. A MAC module as in claim 1, further comprising a proactive protection module for providing the specified number of data packets failed to be received to be greater than the actual number of data packets failed to be received.

7. A media access control (MAC) module in a base station, the MAC module being interfaced to a physical layer receiver for receiving data packets and to a physical layer transmitter for sending data packets, wherein the data packets sent comprise data packets of multicast messages, and wherein the data packets received comprise acknowledgement packets from a plurality of receivers, the MAC module comprising:

a detection module detecting errors in each of the acknowledgement packets received;

a multicast buffer for storing the data packets to be sent sorted according to multicast messages; and

an acknowledgement packet processing module for preparing data packets to be sent in accordance with receiving an acknowledgement packet indicating a specified number of data packets failed to be received by one of the receivers.

8. A MAC module as in claim 7, wherein the specified number of data packets failed to be received is specified implicitly by the time the acknowledgment packet is transmitted by one of the receivers.

9. A MAC module as in claim 8, further comprising a forward error correction (FEC) module for preparing FEC parity packets for data recovery in response to the acknowledgement packet.

10. A MAC module as in claim 7, further comprising an output queue for passing verified data packets from the error detection module for processing by an upper layer protocol.

11. A MAC module as in claim 7, further comprising a channel assignment module for allocating the physical layer transmitter amongst data packets and the acknowledgement packets.

12. A MAC module as in claim 9, further comprising a proactive protection module for providing a number of FEC parity packets greater than the actual number of data packets failed to be received.