Method and system for reliable broadcast or multicast communication in wireless networks

• US 20070268868A1
• Filed: 05/10/2007
• Published: 11/22/2007
• Est. Priority Date: 05/17/2006
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Singh, Harkirat, Shao, Huai-Rong, Ngo, Chiu
• Granted Patent: US 7,920,540 B2
• Time in Patent Office: Days
• US Class Current: 370/331
• CPC Class Codes: H04L 1/1614 using bitmaps
• 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 12/189 in combination with wireless systems selective distribution or broadcast in wireless communication networks H04W4/06
• CPC Class Codes: H04L 2001/0093 Point-to-multipoint
• CPC Class Codes: H04W 72/30 Resource management for broadcast services
• CPC Class Codes: H04W 74/04 Scheduled access hybrid access H04W74/02

Abstract

A method and system for communicating information over a wireless channel in a communication system including a coordinator and receivers, involves controlling channel access by dividing a contention-free period (CFP) into one or more schedules, wherein each schedule includes one or more periodical channel time blocks (CTBs) for wireless communication, reserving a CTB for reliable broadcast or multicast (ReBoM) communication of a data packet over the channel, transmitting the data packet from the coordinator over the channel during the reserved CTB, and receiving one or more acknowledgments for the data packet from one or more of the receivers. The data packet includes a header comprising ReBoM information indicating a multi-CTB ReBoM communication sequence for the data packet or a single-CTB ReBoM communication sequence for the data packet.

Claims

1. A method of communicating information over a wireless channel in a communication system including a coordinator and receivers, comprising the steps of:

controlling channel access by dividing a contention-free period (CFP) into one or more schedules, wherein each schedule includes one or more periodical channel time blocks (CTBs) for wireless communication;

reserving a CTB for reliable broadcast or multicast (ReBoM) communication of a data packet over the channel;

transmitting the data packet from the coordinator over the channel during the reserved CTB; and

receiving one or more scheduled acknowledgments for the data packet from one or more of the receivers.

2. The method of claim 1 wherein the data packet includes a header comprising ReBoM information containing an identity of receivers intended for the transmission.

3. The method of claim 2 wherein the ReBoM information further contains an acknowledgment request for each of one or more of the identified receivers.

4. The method of claim 3 wherein the ReBoM information further contains an indication of a single-CTB communication sequence for the data packet.

5. The method of claim 4 wherein the step of receiving one or more acknowledgments further includes receiving all acknowledgments for the data packet during said reserved CTB.

6. The method of claim 5 further comprising the steps of:

receiving the transmitted data packet at a receiver;

checking the packet header for the ReBoM information;

based on the ReBoM information, checking the data packet for errors and generating an uplink (UL) acknowledgment packet indicating any errors in the data packet; and

transmitting the acknowledgment packet to the coordinator over the channel during the same reserved CTB according to a schedule.

7. The method of claim 3 wherein the ReBoM information further contains an indication of a multi-CTB ReBoM communication sequence for the data packet.

8. The method of claim 1 wherein the step of receiving one or more acknowledgments further includes receiving each acknowledgment for the data packet during a different reserved CTB.

9. The method of claim 8 further comprising the steps of:

receiving the transmitted data packet at a receiver;

checking the packet header for the ReBoM information;

based on the ReBoM information, checking the data packet for errors and generating an UL acknowledgment packet indicating any errors in the data packet;

reserving a CTB for acknowledgment; and

transmitting the acknowledgment packet to the coordinator over the channel during the CTB for acknowledgment according to a schedule.

10. The method of claim 1 wherein the ReBoM communication comprises a one-hop communication.

11. The method of claim 1 wherein:

the data packet includes a header comprising ReBoM information indicating a multi-CTB ReBoM communication sequence for the data packet or a single-CTB ReBoM communication sequence for the data packet; and

the step of receiving acknowledgments further includes;

for single-CTB communication, receiving all acknowledgments for the data packet during said reserved CTB; and

for multi-CTB communication, receiving each acknowledgment for the data packet during a different reserved CTB.

12. The method of claim 11 further comprising the steps of:

receiving the transmitted data packet at a receiver;

checking the packet header for the ReBoM information;

based on the ReBoM information;

checking the data packet for errors and generating an UL acknowledgment packet indicating any errors in the data packet;

for multi-CTB communication, reserving a CTB for acknowledgment, and transmitting the acknowledgment packet to the coordinator over the channel during the CTB for acknowledgment according to a schedule indicated in the data packet; and

for single-CTB communication, transmitting the acknowledgment packet to the coordinator over the channel during the same reserved CTB according to a schedule indicated in the data packet.

13. The method of claim 1 wherein the data packet includes a header comprising ReBoM information indicating that the data packet is part of a ReBoM communication sequence.

14. The method of claim 13 further comprising the step of:

for a data packet that is part of a ReBoM communication sequence, including ReBoM information in the packet MAC header including;

the identity of receivers intended for the transmission, an acknowledgment request for each of one or more of the identified receivers, and an indication of a single-CTB or multi-CTB communication sequence for the data packet.

15. The method of claim 14 further comprising the steps of:

receiving the transmitted data packet at a receiver;

checking the packet header for the ReBoM information; and

based on the ReBoM information;

checking the data packet for errors and generating an UL acknowledgment packet indicating any errors in the data packet;

for multi-CTB communication, reserving a CTB for acknowledgment, and transmitting the acknowledgment packet to the coordinator over the channel during the CTB for acknowledgment according to a schedule indicated in the data packet; and

for single-CTB communication, transmitting the acknowledgment packet to the coordinator over the channel during the same reserved CTB according to a schedule indicated in the data packet.

16. The method of claim 1, further comprising the steps of:

receiving the transmitted data packet at a receiver;

generating an UL acknowledgment packet indicating any errors in the data packet; and

transmitting the acknowledgment packet to the coordinator over the channel during the same reserved CTB, after a time period beyond the end of the transmission of the data packet.

17. The method of claim 1 wherein said time period is a function of the number of receivers identified in the data packet header.

18. The method of claim 17 wherein said time period is determined as N*IFS+(N−

1)*Ack_Duration time units wherein N represents the total number of receivers identified in the data packet header, IFS represents an Inter-Frame Space (IFS) duration for channel switching and other overhead, and Ack_Duration time units represents the amount of time needed for uplink transmission of an acknowledgment packet.

19. The method of claim 1 further comprising the step of retransmitting the data packet to the receivers indicated by the acknowledgments.

20. The method of claim 1 further comprising the step of including CRC information in the data packet for transmission error detection.

21. An apparatus for communicating information over a wireless channel in a communication system, comprising a coordinator including:

a scheduler configured for controlling channel access by dividing a contention-free period (CFP) into one or more schedules, wherein each schedule includes one or more periodic channel time blocks (CTBs) for wireless communication, and reserving a CTB for data packet communication over the channel;

a communication module for reliable broadcast or multicast (ReBoM) communication of a data packet over the channel during the reserved CTB, and receiving one or more acknowledgments for a data packet from one or more receivers.

22. The apparatus of claim 21 wherein the data packet includes a header comprising ReBoM information containing the identity of receivers intended for the transmission.

23. The apparatus of claim 22 wherein the ReBoM information further contains an acknowledgment request for each of one or more of the identified receivers.

24. The apparatus of claim 23 wherein the ReBoM information further contains an indication of a single-CTB communication sequence for the data packet.

25. The apparatus of claim 24 wherein the communication module is further configured for receiving all acknowledgments for the data packet during said reserved CTB.

26. The apparatus of claim 23 wherein the ReBoM information further contains an indication of a multi-CTB ReBoM communication sequence for the data packet.

27. The apparatus of claim 21 wherein the communication module is further configured for receiving each acknowledgment for the data packet during a different reserved CTB.

28. The apparatus of claim 21 wherein the ReBoM communication comprises a one-hop communication.

29. The apparatus of claim 21 wherein:

the data packet includes a header comprising ReBoM information indicating a multi-CTB ReBoM communication sequence for the data packet or a single-CTB ReBoM communication sequence for the data packet; and

the communication module is further configured such that for a single-CTB communication, the communication module receives all acknowledgments for the data packet during said reserved CTB, and for a multi-CTB communication, the communication module receives each acknowledgment for the data packet during a different reserved CTB.

30. The apparatus of claim 21 wherein the data packet includes a header comprising ReBoM information indicating that the data packet is part of a ReBoM communication sequence.

31. The apparatus of claim 30 wherein for a data packet that is part of a ReBoM communication sequence, ReBoM information is included in the packet MAC header including the identity of receivers intended for the transmission, an acknowledgment request for each of one or more of the identified receivers, and an indication of a single-CTB or multi-CTB communication sequence for the data packet.

32. The apparatus of claim 21 wherein said time period is a function of the number of receivers identified in the data packet header.

33. The apparatus of claim 32 wherein said time period is determined as N*IFS+(N−

1)*Ack_Duration time units wherein N represents the total number of receivers identified in the data packet header, IFS represents an Inter-Frame Space (IFS) duration for channel switching and other overhead, and Ack_Duration time units represents the amount of time needed for uplink transmission of an acknowledgment packet.

34. The apparatus of claim 21 wherein the communication module is further configured for retransmitting the data packet to the receivers indicated by the acknowledgments.

35. The apparatus of claim 21 wherein the communication module is further configured for including cyclic redundancy code (CRC) information in the data packet for transmission error detection.

36. A receiver for communicating information over a wireless channel in a communication system, comprising:

a communication module configured for receiving the transmitted data packet during a reserved channel time block (CTB) period, checking each packet header for reliable broadcast or multicast (ReBoM) information and checking the data packet for errors based on the ReBoM information; and

an acknowledgment module for generating an uplink (UL) acknowledgment packet indicating any errors in the data packet, and transmitting the acknowledgment packet to the coordinator over the channel during the same reserved CTB according to a schedule.

37. The receiver of claim 36 wherein the ReBoM information further contains an indication of a multi-CTB ReBoM communication sequence for the data packet.

38. The receiver of claim 36 wherein the acknowledgment module is further configured for sending each acknowledgment for the data packet during a different reserved CTB.

39. The receiver of claim 38 wherein:

the communication module is further configured for checking the data packet for errors and generating an UL acknowledgment packet indicating any errors in the data packet;

the acknowledgment module is further configured for transmitting the acknowledgment packet to the coordinator over the channel during a reserved CTB for acknowledgment according to a schedule.

40. The receiver of claim 36 wherein the ReBoM communication comprises a one-hop communication.

41. The receiver of claim 36 wherein:

the data packet includes a header comprising ReBoM information indicating a multi-CTB ReBoM communication sequence for the data packet or a single-CTB ReBoM communication sequence for the data packet; and

the acknowledgment module is further configured such that for a single-CTB communication, the acknowledgment module sends all acknowledgments for the data packet during said reserved CTB, and for a multi-CTB communication, the acknowledgment module sends each acknowledgment for the data packet during a different reserved CTB.

42. The receiver of claim 41 wherein:

the acknowledgment module is further configured such that based on the ReBoM information, the acknowledgment module;

checks the data packet for errors and generates an UL acknowledgment packet indicating any errors in the data packet;

for a multi-CTB communication, reserves a CTB for acknowledgment, and transmits the acknowledgment packet to a coordinator over the channel during the CTB for acknowledgment according to a schedule indicated in the data packet; and

for a single-CTB communication, transmits the acknowledgment packet to the coordinator over the channel during the same reserved CTB according to a schedule indicated in the data packet.

43. The receiver of claim 36 wherein the data packet includes a header comprising ReBoM information indicating that the data packet is part of a ReBoM communication sequence.

44. The receiver of claim 43 wherein for a data packet that is part of a ReBoM communication sequence, ReBoM information is included in the packet MAC header including the identity of receivers intended for the transmission, an acknowledgment request for each of one or more of the identified receivers, and an indication of a single-CTB or multi-CTB communication sequence for the data packet.

45. The receiver of claim 44 wherein:

the acknowledgment is further configured for;

checking the data packet for errors based on the ReBoM information, and generating an UL acknowledgment packet indicating any errors in the data packet;

for a multi-CTB communication, reserving a CTB for acknowledgment, and transmitting the acknowledgment packet to a coordinator over the channel during the CTB for acknowledgment according to a schedule indicated in the data packet; and

for a single-CTB communication, transmitting the acknowledgment packet to the coordinator over the channel during the same reserved CTB according to a schedule indicated in the data packet.

46. The receiver of claim 36, wherein:

the acknowledgment module is further configured for generating an UL acknowledgment packet indicating any errors in the data packet, and transmitting the acknowledgment packet to a coordinator over the channel during the same reserved CTB, after time period beyond the end of the transmission of the data packet.

47. The receiver of claim 36 wherein said time period is a function of the number of receivers identified in the data packet header.

48. The receiver of claim 47 wherein said time period is determined as N*IFS+(N−

1)*Ack_Duration time units wherein N represents the total number of receivers identified in the data packet header, IFS represents an Inter-Frame Space (IFS) duration for channel switching and other overhead, and Ack_Duration time units represents the amount of time needed for uplink transmission of an acknowledgment packet.

49. A method of communicating information over a wireless channel in a communication system including a coordinator and receivers, comprising the steps of:

controlling channel access by dividing a contention-free period (CFP) into one or more schedules, wherein each schedule includes one or more periodical channel time blocks (CTBs) for wireless communication;

reserving a CTB for communication of a data packet over the channel, the packet including a MAC header indicating whether it is a ReBoM or a No-ReBoM packet;

transmitting the data packet from the coordinator over the channel during the reserved CTB; and

receiving one or more scheduled acknowledgments for the data packet from one or more of the receivers;

wherein for a No-ReBoM packet, the identity of intended receivers and acknowledgment requests are not included in the packet, and for a ReBoM packet, the identity of intended receivers and acknowledgment requests are included in the packet.

50. The method of claim 49 further comprising the steps of:

receiving the transmitted data packet at a receiver;

generating an UL acknowledgment packet indicating any errors in the data packet; and

using the angular position of each device in the communication system to optimize UL acknowledgment transmission.

51. The method of claim 49 wherein:

transmitting the data packet further includes, for a first contention-based control period (CBCP), setting the source to the coordinator and setting the destination to a broadcast or multicast address, thereafter, the coordinator assigning CBCPs for UL acknowledgment transmission for the packet from a receiver, such that in one CBCP one UL acknowledgment is transmitted from a receiver.

52. The method of claim 51 further comprising the steps of:

for a station with a MAC address k, the coordinator allocating a CBCP for the receiver with the source address as the MAC address of the receiver, K, and setting the destination address to the MAC address of the coordinator.