Method and system for channel access control for transmission of video information over wireless channels

• US 20070230338A1
• Filed: 03/22/2007
• Published: 10/04/2007
• Est. Priority Date: 03/29/2006
• 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 8,179,871 B2
• Time in Patent Office: Days
• US Class Current: 370/230
• CPC Class Codes: H04B 7/2659 for data rate control
• CPC Class Codes: H04N 21/4122 additional display device, e.g. video projector digital output for controlling a plurality of local displays G06F3/1423
• CPC Class Codes: H04N 21/43615 Interfacing a Home Network, e.g. for connecting the client to a plurality of peripherals home Audio Video Interoperability [HAVI] data switching networks H04L12/2805
• CPC Class Codes: H04N 21/43637 involving a wireless protocol, e.g. Bluetooth, RF or wireless LAN [IEEE 802.11] arrangements for wireless networking or broadcasting of information in indoor or near-field type systems H04B10/114
• CPC Class Codes: H04W 74/006 in the downlink, i.e. towards the terminal
• CPC Class Codes: H04W 74/04 Scheduled access hybrid access H04W74/02

Abstract

A method and system for channel access control for transmission of uncompressed video information over wireless channels. A contention-free period (CFP) for high-rate and low-rate channels is divided into schedules in which one or multiple periodical channel time blocks are reserved for wireless transmission of isochronous streams.

Claims

1. A method for communication of video information over wireless channels in a communication system including senders and receivers, comprising the steps of:

packetizing video information of one or more video streams into packets for transmission over a wireless channel;

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) reserved for transmission of isochronous streams; and

transmitting packets from a sender to a receiver during the channel time blocks.

2. The method of claim 1 wherein:

controlling channel access further includes controlling channel access by dividing the CFP into channel time blocks for a high-rate channel and a low-rate channel into schedules; and

transmitting packets further includes the steps of;

transmitting packets of video information from a sender to a receiver over the high-rate channel during the channel time blocks, and transmitting acknowledgment packets from the receiver to sender over the low-rate channel during the channel time blocks.

3. The method of claim 2 wherein controlling channel access further includes providing a superframe period comprising a beacon frame that provides schedule timing allocations for dividing the contention-free period (CFP) into channel time blocks.

4. The method of claim 3 wherein the superframe further comprises a contention-based control period (CBCP) for communicating control and management commands over a low-rate channel.

5. The method of claim 4 wherein no information is transmitted over a high-rate channel during a CBCP.

6. The method of claim 4 wherein the superframe further comprises a beam-search period (BSP) for searching transmission beams.

7. The method of claim 4 further comprising the steps of periodically transmitting a beacon to signal the start of a superframe period.

8. The method of claim 4 wherein the beacon specifies the start time, and length, of the CBCP and CFP in the corresponding superframe.

9. The method of claim 8 wherein the beacon specifies an allocation of channel time blocks to different senders and receivers.

10. The method of claim 9 wherein the beacon further specifies an allocation of channel time blocks to different streams.

11. The method of claim 4 wherein channel access during the CFP is based on Time Division Multiple Access (TDMA).

12. The method of claim 4 wherein each schedule comprises a series of evenly distributed CTBs with equal length, in the CFP.

13. The method of claim 4 further comprising the steps of:

a sender transmitting a bandwidth request command for transmission of both isochronous streams and asynchronous data over a channel; and

if sufficient bandwidth remains in the channel, then allocating a schedule in the CFP to the sender.

14. The method of claim 13 further comprising the step of allocating multiple schedules to the sender.

15. The method of claim 13 further comprising the step of the sender transmitting multiple streams to a receiver over the channel during the allocated schedule.

16. The method of claim 13 further comprising the steps of:

the sender transmitting a stream to a receiver over the channel during the allocated schedule; and

the receiver transmitting an ACK to the sender during the schedule.

17. The method of claim 16 wherein during a CTB one or more packets are transmitted from the sender to the receiver, and one or more corresponding ACKs are transmitted from the receiver to the sender.

18. A system for communication of video information over wireless channels, comprising:

a coordinator configured for 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) reserved for transmission of isochronous streams; and

a transmitter including a packetizer configured to place video information of one or more video streams into packets for transmission over a wireless channel, and a communication module for transmitting packets to a receiver over a high-rate channel during the channel time blocks.

19. The system of claim 18 further comprising a receiver configured for transmitting acknowledgment packets from the receiver to the transmitter during the channel time blocks over a low-rate channel.

20. The system of claim 19 wherein the coordinator is further configured to provide a superframe period comprising a beacon frame that includes schedule timing allocations for dividing the CFP into channel time blocks.

21. The system of claim 20 wherein the superframe further comprises a CBCP for communicating control and management commands over a low-rate channel.

22. The system of claim 21 wherein no information is transmitted over a high-rate channel during the CBCP.

23. The system of claim 21 wherein the superframe further comprises a BSP for searching transmission beams.

24. The system of claim 21 wherein the coordinator is further configured to periodically transmit a beacon to signal the start of a superframe period.

25. The system of claim 21 wherein the beacon specifies the start time, and length, of the CBCP and CFP in the corresponding superframe.

26. The system of claim 25 wherein the beacon specifies an allocation of channel time blocks to different senders and receivers.

27. The system of claim 26 wherein the beacon further specifies an allocation of channel time blocks to different streams.

28. The system of claim 21 wherein channel access during the CFP is based on TDMA.

29. The system of claim 21 wherein each schedule comprises a series of evenly distributed CTBs with equal length, in the CFP.

30. The system of claim 21 wherein:

the transmitter is further configured to transmit a bandwidth request command for transmission of both isochronous streams and asynchronous data over a channel; and

the controller is further configured to determine if sufficient bandwidth remains in the channel, and if sufficient bandwidth remains in the channel then allocate a schedule in the CFP for transmission of both isochronous streams and asynchronous data by the transmitter over the channel.

31. The system of claim 30 wherein the coordinator is further configured to allocate multiple schedules to the transmitter.

32. The system of claim 30 wherein the transmitter is further configured to transmit multiple streams to the receiver over the channel during the allocated schedule.

33. The system of claim 30 wherein:

the transmitter is further configured to transmit a stream to the receiver over the channel during the allocated schedule; and

the receiver is further configured to transmitting an ACK to the sender during the schedule.

34. The system of claim 33 wherein during a CTB, one or more packets are transmitted from the transmitter to the receiver, and one or more corresponding ACKs are transmitted from the receiver to the transmitter.

35. A coordinator for controlling communication of video information over wireless channels in a communication network, comprising:

a scheduler configured to divide a contention-free period (CFP) into one or more schedules, wherein each schedule includes one or more periodical channel time blocks (CTBs) reserved for transmission of isochronous streams; and

a controller configured to receive a bandwidth request, and allocate channel bandwidth based on said schedules to control channel access.

36. The coordinator of claim 35 wherein:

the controller is configured to receive a bandwidth request over a low-rate channel from a wireless transmitter, and allocate channel bandwidth based on said schedules to control access to a high-rate channel by the transmitter for transmission of video information to a wireless receiver over the high-rate channel.

37. The coordinator of claim 36 wherein the scheduler is configured to provide a superframe period comprising a beacon frame that includes schedule timing allocations for dividing the CFP into channel time blocks.

38. The coordinator of claim 37 wherein the superframe further comprises a CBCP for communicating control and management commands over a low-rate channel.

39. The coordinator of claim 38 wherein no information is transmitted over a high-rate channel during the CBCP.

40. The coordinator of claim 38 wherein the superframe further comprises a BSP for searching transmission beams.

41. The coordinator of claim 38 wherein the coordinator is further configured to periodically transmit a beacon to signal the start of a superframe period.

42. The coordinator of claim 38 wherein the beacon specifies the start time, and length, of the CBCP and CFP in the corresponding superframe.

43. The coordinator of claim 42 wherein the beacon specifies an allocation of channel time blocks to different senders and receivers.

44. The coordinator of claim 43 wherein the beacon further specifies an allocation of channel time blocks to different streams.

45. The coordinator of claim 38 wherein channel access during the CFP is based on TDMA.

46. The coordinator of claim 38 wherein each schedule comprises a series of evenly distributed CTBs with equal length, in the CFP.

47. The coordinator of claim 38 wherein:

the network includes a transmitter configured to transmit a bandwidth request to the coordinator for transmission of both isochronous streams and asynchronous data over a channel; and

the controller is further configured to determine if sufficient bandwidth remains in the channel, and if sufficient bandwidth remains in the channel then allocate a schedule in the CFP for transmission of both isochronous streams and asynchronous data by the transmitter over the channel.

48. The coordinator of claim 47 wherein the controller is further configured to allocate multiple schedules to the transmitter.

49. The coordinator of claim 47 wherein the transmitter is further configured to transmit multiple streams to the receiver over the channel during the allocated schedule.

50. The coordinator of claim 47 wherein the network further includes a receiver, such that the transmitter is configured to transmit a stream to the receiver over the channel during the allocated schedule, and the receiver is configured to transmit an ACK to the sender during the allocated schedule.

51. The coordinator of claim 50 wherein during a CTB, one or more packets are transmitted from the transmitter to the receiver, and one or more corresponding ACKs are transmitted from the receiver to the transmitter.