SYSTEM AND METHOD FOR CONTENTION-BASED CHANNEL ACCESS FOR PEER-TO-PEER CONNECTION IN WIRELESS NETWORKS

• US 20100172296A1
• Filed: 11/25/2009
• Published: 07/08/2010
• Est. Priority Date: 01/05/2009
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Singh, Harkirat, Ngo, Chiu
• Granted Patent: US 8,811,420 B2
• Time in Patent Office: Days
• US Class Current: 370/328
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

A system and method for wireless communication is disclosed. One aspect of the system includes wireless devices, wherein the wireless devices are capable of establishing a peer-to-peer link by contention-based channel access, and wherein the wireless devices are free to contend any time for accessing a wireless channel. The system may include first and second wireless devices, each of which has a directional antenna system. The first wireless device can determine whether the wireless channel is available for establishing a peer-to-peer link, by repeating sensing whether the channel is idle in different directions each during different slot time periods. The first wireless device can also sequentially transmit multiple requests each in different directions for establishing a link with the second wireless device. The second wireless device can sequentially transmit multiple replies each in different directions for establishing the link with the first wireless device.

Claims

1. A method of communication in a wireless network comprising non-access point wireless devices, wherein the wireless devices are capable of establishing a peer-to-peer link by contention-based channel access, and wherein the wireless devices are free to contend any time for accessing a wireless channel, the method comprising:

determining, by a non-access point wireless device having a directional antenna system in the wireless network, whether a wireless channel is available for establishing a peer-to-peer link by;

sensing whether the channel is idle in a first direction during a first slot time period by orienting the directional antenna system toward the first direction, and

sensing whether the channel is idle in a second direction different from the first direction during a second slot time period by orienting the directional antenna system toward the second direction.

2. The method of claim 1, wherein the wireless channel has a frequency equal to or greater than 6 GHz.

3. The method of claim 1, wherein determining whether the wireless channel is available comprises repeatedly sensing whether the channel is idle in a plurality of different directions during further other slot time periods by orienting the directional antenna toward the different directions until the wireless channel has been sensed in substantially all directions.

4. The method of claim 3, wherein the directional antenna system is configured to cover different angular ranges for two or more of the different directions.

5. The method of claim 3, wherein the directional antenna system is configured to cover an angular range of about 360°

/k in each of the different directions, and wherein determining whether the wireless channel is available comprises repeatedly sensing whether the channel is idle in each of k-number of different directions during a respective one of k-number of slot time periods.

6. The method of claim 5, wherein determining whether the wireless channel is available comprises determining whether the wireless channel is available during at least part of Distributed Coordination Function (DCF) Interframe Space (DIFS).

7. The method of claim 6, wherein each of the k-number of slot time periods has a duration the same as the duration of one aSlotTime.

8. The method of claim 7, wherein each of the k-number of slot time periods includes, in sequence, aCCATime, aRxTxTurnaroundTime, aAirPropagationTime, and aMACProcessingDelay.

9. The method of claim 8, wherein determining whether the wireless channel is available comprises:

waiting for a short interframe space (SIFS) period after the end of the k-number of slot time periods; and

waiting for one aSlotTime after the end of the SIFS period.

10. The method of claim 5, further comprising:

transmitting, by the wireless device, multiple requests in different directions for establishing a link with another non-access point wireless device in the wireless network; and

transmitting, by the other wireless device having a directional antenna system comprising an array of antenna elements, one or more reply messages for establishing the link, using the directional antenna system.

11. The method of claim 10, wherein transmitting the one or more reply messages comprises transmitting a reply message in a selected direction, using less than all of the antenna elements of the directional antenna system of the other wireless device.

12. The method of claim 11, wherein transmitting the reply message comprises transmitting a single reply message for a duration substantially the same as a total duration of the k-number of slot time periods.

13. The method of claim 1, wherein sensing whether the channel is idle during the first slot time period comprises:

accessing the channel during a first sub-period in the first direction to detect whether the channel is busy or idle;

changing a physical layer of the wireless device from a first mode for receiving a symbol of a frame on the channel to a second mode for transmitting a symbol on the channel during a second sub-period;

waiting for a third sub-period for a signal to travel on the channel from the wireless device to another wireless device in the wireless network; and

processing a received frame at a medium access control (MAC) layer of the wireless device during a fourth sub-period.

14. The method of claim 1, further comprising:

transmitting, by the wireless device, multiple requests for establishing a link with another non-access point wireless device in the wireless network, the requests being addressed to the other wireless device, by;

transmitting a first request in a first request transmission direction by orienting the directional antenna system toward the first request transmission direction, and

transmitting a second request in a second request transmission direction by orienting the directional antenna system toward the second request transmission direction.

15. The method of claim 14, wherein transmitting the multiple requests comprises repeatedly transmitting another request in a different direction by orienting the directional antenna toward the different direction until the requests have been transmitted in substantially all directions.

16. The method of claim 15, wherein the directional antenna system is configured to cover an angular range of about 360°

/k in each of the first and second request transmission directions, and wherein transmitting the multiple requests comprises transmitting k-number of requests each in respective different directions.

17. The method of claim 14, wherein the antenna system comprises an array of antenna elements, and wherein the method further comprises receiving, by the wireless device, a reply message by using less than all of the antenna elements.

18. The method of claim 17, further comprising:

waiting for a short interframe space (SIFS) period from the end of reply message; and

transmitting data to the second wireless device after waiting for the SIFS period.

19. The method of claim 14, further comprising receiving, by the wireless device, a reply message by orienting the directional antenna system toward a selected direction.

20. The method of claim 14, wherein one or more of the multiple requests comprises a field indicative of the end time of the request.

21. The method of claim 20, wherein the one or more of the multiple requests further comprise one or more of a frame control field, a duration field, a receiver address field, a transmitter address field, and a frame check sequence field.

22. A method of communication in a wireless network comprising non-access point wireless devices, wherein the wireless devices are capable of establishing a peer-to-peer link by contention-based channel access, wherein the wireless devices are free to contend any time for accessing a wireless channel, the method comprising:

receiving, by a non-access point wireless device in the wireless network, a request addressed to the wireless device for establishing a link with another non-access point wireless device in the wireless network, wherein the wireless device comprises a directional antenna system including an array of antenna elements; and

transmitting, by the wireless device, multiple replies for establishing the link, the replies being addressed to the other wireless device, by;

transmitting a first reply in a first reply transmission direction by orienting the directional antenna system toward the first reply transmission direction, and

transmitting a second reply in a second reply transmission direction by orienting the directional antenna system toward the second reply transmission direction.

23. The method of claim 22, wherein receiving the request comprises using less than all of the antenna elements.

24. The method of claim 22, wherein transmitting the multiple replies comprises:

repeatedly transmitting another reply in a different direction by orienting the directional antenna toward the different direction until the replies have been transmitted in substantially all directions.

25. The method of claim 24, wherein the directional antenna system is configured to cover an angular range of about 360°

/k in each of the first and second reply transmission directions, and wherein transmitting the multiple replies comprises;

transmitting k-number of replies each in respective different directions.

26. A method of communication in a wireless network comprising non-access point wireless devices, wherein the wireless devices are capable of establishing a peer-to-peer link by contention-based channel access, wherein the wireless devices are free to contend any time for accessing a wireless channel, the method comprising:

determining, by a first non-access point wireless device having a directional antenna system in the wireless network, whether a wireless channel is available for establishing a peer-to-peer link, wherein determining whether the wireless channel is available comprises repeatedly sensing whether the channel is idle in each of different directions during a respective one of different slot time periods;

sequentially transmitting, by the first wireless device, multiple requests each in respective different directions for establishing a link with a second non-access point wireless device in the wireless network, the requests being addressed to the second wireless device; and

sequentially transmitting, by the second wireless device, multiple replies each in respective different directions for establishing the link with the first wireless device, the replies being addressed to the first wireless device.

27. The method of claim 26, wherein determining whether the wireless channel is available comprises repeatedly sensing whether the channel is idle in a plurality of different directions until the wireless channel has been sensed in substantially all directions;

wherein transmitting the multiple requests comprises repeatedly transmitting requests in respective different directions until the requests have been transmitted in substantially all directions; and

wherein transmitting the multiple replies comprises repeatedly transmitting replies in respective different directions until the replies have been transmitted in substantially all directions.

28. The method of claim 26, wherein one or more of the multiple requests comprise a field indicative of the end time of completing transmission of the multiple requests, and wherein transmitting the multiple replies comprises transmitting the first one of the multiple replies after the end time.

29. The method of claim 26, wherein one or more of the multiple replies comprise a field indicative of the end time of completing transmission of the multiple replies, and wherein the method further comprises transmitting data from the first wireless device to the second wireless device after the end time.

30. A non-access point wireless device for wireless communication in a wireless network including a plurality of non-access point wireless devices, the device comprising:

a directional antenna system; and

a medium access control (MAC) layer configured to establish a peer-to-peer link by contention-based channel access, wherein the wireless device is free to contend any time for accessing a wireless channel,

wherein the MAC layer is further configured to determine whether the wireless channel is available for establishing a peer-to-peer link, using the directional antenna system, by;

sensing whether the channel is idle in a first direction during a first slot time period by orienting the directional antenna system toward the first direction, and

sensing whether the channel is idle in a second direction different from the first direction during a second slot time period by orienting the directional antenna system toward the second direction.

31. The device of claim 30, wherein the wireless channel has a frequency equal to or greater than 6 GHz.

32. The device of claim 30, wherein the MAC layer is configured to repeatedly sense whether the channel is idle in a plurality of different directions during further other slot time periods by orienting the directional antenna toward the different directions until the wireless channel has been sensed in substantially all directions.

33. The method of claim 32, wherein the directional antenna system is configured to cover different angular ranges for two or more of the different directions.

34. The device of claim 32, wherein the directional antenna system is configured to cover an angular range of 360°

/k in each of the different directions, and wherein the MAC layer is configured to repeatedly sense whether the channel is idle in each of k-number of different directions during a respective one of k-number of slot time periods.

35. The device of claim 34, wherein the MAC layer is configured to determine whether the wireless channel is available during at least part of Distributed Coordination Function (DCF) Interframe Space (DIFS).

36. The device of claim 35, wherein each of the k-number of slot time periods has a duration the same as the duration of one aSlotTime, and wherein each of the k-number of slot time periods includes, in sequence, aCCATime, aRxTxTurnaroundTime, aAirPropagationTime, and aMACProcessingDelay.

37. The device of claim 36, wherein the MAC layer is further configured to wait for a short interframe space (SIFS) period after the end of the k-number of slot time periods, and wherein the MAC layer is further configured to wait for one aSlotTime after the end of the SIFS period.

38. The device of claim 30, wherein the MAC layer is further configured to:

access the channel during a first sub-period in the first direction to detect whether the channel is busy or idle;

change a physical layer of the wireless device from a first mode for receiving a symbol of a frame on the channel to a second mode for transmitting a symbol on the channel during a second sub-period;

wait for a third sub-period for a signal to travel on the channel from the wireless device to another wireless device in the wireless network; and

process a received frame during a fourth sub-period.

39. The device of claim 30, wherein the MAC layer is further configured to transmit multiple requests for establishing a link with another non-access point wireless device in the wireless network, the requests being addressed to the other wireless device, by:

transmitting a first request in a first request transmission direction by orienting the directional antenna system toward the first request transmission direction, and

transmitting a second request in a second request transmission direction by orienting the directional antenna system toward the second request transmission direction.

40. The device of claim 39, wherein the MAC layer is further configured to repeatedly transmit another request in a different direction by orienting the directional antenna toward the different direction until the requests have been transmitted in substantially all directions.

41. The device of claim 40, wherein the directional antenna system is configured to cover an angular range of about 360°

/k in each of the first and second request transmission directions, and wherein the MAC layer is further configured to transmit k-number of requests each in respective different directions.

42. The device of claim 39, wherein the antenna system comprises an array of antenna elements, and wherein the MAC layer is further configured to receive a reply message after transmitting the multiple requests, by using less than all of the antenna elements.

43. The device of claim 42, wherein the MAC layer is further configured to wait for a short interframe space (SIFS) period from the end of reply message;

and to transmit data to the second wireless device.

44. The device of claim 39, wherein the MAC layer is further configured to receive a reply message by orienting the directional antenna system toward a selected direction after transmitting the multiple requests.

45. The device of claim 39, wherein one or more of the multiple requests comprises a field indicative of the end time of the request.

46. The device of claim 45, wherein the one or more of the multiple requests further comprise one or more of a frame control field, a duration field, a receiver address field, a transmitter address field, and a frame check sequence field.

47. A non-access point wireless device for wireless communication in a wireless network including a plurality of non-access point wireless devices, the device comprising:

a directional antenna system including an array of antenna elements; and

a medium access control (MAC) layer configured to establish a peer-to-peer link by contention-based channel access, wherein the wireless device is free to contend any time for accessing a wireless channel,

wherein the MAC layer is further configured to receive a request addressed to the wireless device for establishing a link with another non-access point wireless device, by using less than all of the antenna elements;

wherein the MAC layer is further configured to transmit multiple replies for establishing the link, the replies being addressed to the other wireless device, by;

transmitting a first reply in a first reply transmission direction by orienting the directional antenna system toward the first reply transmission direction, and

transmitting a second reply in a second reply transmission direction by orienting the directional antenna system toward the second reply transmission direction.

48. The device of claim 47, wherein the MAC layer is configured to repeatedly transmitting another reply in a different direction by orienting the directional antenna toward the different direction until the replies have been transmitted in substantially all directions.

49. The device of claim 48, wherein the directional antenna system is configured to cover an angular range of about 360°

/k in each of the first and second reply transmission directions, and wherein the MAC layer is configured to transmit k-number of replies each in respective different directions.

50. A wireless system comprising non-access point wireless devices, wherein the wireless devices are capable of establishing a peer-to-peer link by contention-based channel access, wherein the wireless devices are free to contend any time for accessing a wireless channel, the system comprising:

a first non-access point wireless device in the wireless network, the first wireless device having a directional antenna system; and

a second non-access point wireless device in the wireless network, the second wireless device having a directional antenna system,

wherein the first wireless device is configured to determine whether a wireless channel is available for establishing a peer-to-peer link, by repeatedly sensing whether the channel is idle in each of different directions during a respective one of different slot time periods;

wherein the first wireless device is further configured to sequentially transmit multiple requests each in respective different directions for establishing a link with the second wireless device, the requests being addressed to the second wireless device; and

wherein the second wireless device is configured to sequentially transmit multiple replies each in respective different directions for establishing the link, the replies being addressed to the first wireless device.

51. The device of claim 50, wherein the first wireless device is configured to repeatedly sensing whether the channel is idle in a plurality of different directions until the wireless channel has been sensed in substantially all directions;

wherein the first wireless device is configured to repeatedly transmitting requests in respective different directions until the requests have been transmitted in substantially all directions; and

wherein the second wireless device is configured to repeatedly transmitting replies in respective different directions until the replies have been transmitted in substantially all directions.