Method and system for shared communication medium in wireless communication systems

• US 8,570,970 B2
• Filed: 04/30/2012
• Issued: 10/29/2013
• Est. Priority Date: 03/06/2009
• Status: Expired due to Fees

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Hsu, Ju-Lan, Shao, Huai-Rong, Ngo, Chiu
• Primary Examiner(s): Phan, Tri H
• Application Number:
  US13/460,642
• Publication Number:
  US 20120213208A1
• Time in Patent Office: 547 Days
• Field of Search: 370310-350, 370431-437, 370445-463, 455/434, 455450-4522, 455/464, 455509-512
• US Class Current: 370/329
• CPC Class Codes: H04W 74/002 Transmission of channel access control information
• CPC Class Codes: H04W 74/02 Hybrid access

Abstract

Performing distributed contention-free communication channel reservation for wireless communication, is disclosed. One implementation involves providing access to a shared communication channel in a wireless network including multiple wireless stations, by performing distributed channel time reservation for contention-free access to a shared wireless channel by each wireless station, based on a prior successful contention by the wireless station for access to the channel in a wireless network.

Claims

1. A method for transmitting information in a wireless network including multiple wireless stations, the method comprising:

transmitting information in the wireless network using distributed channel time reservation for contention-free access to a wireless channel by each wireless station, based on a prior successful contention by the wireless station for access to the channel in a wireless network.

2. The method of claim 1 wherein performing said distributed channel time reservation comprises:

a wireless station contending for access to the channel;

upon successful contention, the wireless station obtaining ownership of a channel time block (CTB) by reserving the CTB as a CTB-owner station for transmitting on the channel during the owned CTB; and

the wireless station retaining information about the successful contention for performing future contention-free channel reservations.

3. The method of claim 2 further comprising:

the wireless station attempting a contention-free channel reservation based on the retained information about said successful contention.

4. The method of claim 3, wherein said information about the successful contention comprises timing of said owned CTB in a specific channel time period comprising a superframe, wherein each superframe comprises multiple CTBs.

5. The method of claim 4, wherein attempting a contention-free channel reservation based on said retained information comprises:

the wireless station attempting a reservation-based channel access in a subsequent CTB within a current superframe or in a future superframe based on timing of said owned CTB within a superframe, according to the data traffic characteristics of the wireless station.

6. The method of claim 4, wherein attempting a contention-free channel reservation based on the retained information comprises:

the wireless station attempting a reservation-based channel access in a target CTB in a future superframe, the target CTB having the same relative time location as the owned CTB in the current superframe.

7. The method of claim 6, wherein attempting a contention-free channel reservation based on the retained information comprises:

the wireless station attempting a reservation-based channel access in a target CTB in a future superframe, the target CTB having the same relative time location as the owned CTB in the current superframe, wherein multiple wireless stations contend for CTBs.

8. The method of claim 4 wherein attempting a contention-free channel reservation based on the retained information comprises:

the wireless station entering an assessment stage for;

determining if its transmissions during a target CTB may cause interference to any existing CTB-owner station of the target CTB in an upcoming superframe; and

determining if its transmissions during a target CTB may cause interference to any existing CTB-owner station of the target CTB in an upcoming CTB in the current superframe.

9. The method of claim 8, wherein attempting a contention-free channel reservation based on the retained information further comprises:

upon determining lack of interference with any existing CTB-owner station, the wireless station obtaining ownership of the target CTB as owner of the target CTB.

10. The method of claim 9 further comprising:

upon becoming owner of a CTB, the wireless station initiating channel access in a contention free period of the owned CTB and scheduling transmissions therein, until the wireless station releases its ownership of the owned CTB or until its ownership expires.

11. The method of claim 10 wherein:

each CTB provides contention-free access and all-access opportunities; and

contending for channel access comprises the wireless station contending for at least a portion of a CTB that is unused by any CTB-owner station outside contention-free opportunities.

12. The method of claim 10 further comprising:

for schedule fairness between multiple wireless stations, specifying contention-based channel access priorities based on the quantity of CTB-ownership of each wireless station.

13. The method of claim 1 further comprising performing said distributed channel time block reservation in the absence of a network coordinator.

14. The method of claim 1 wherein:

the wireless network comprises a legacy wireless station and non-legacy wireless stations, wherein only the non-legacy wireless stations are reservation-aware;

distributed CTB reservation further comprises;

performing timing-based spoofing of the legacy station to protect the owned CTB as reserved by a CTB-owner station from access by the legacy station.

15. The method of claim 14 further comprising:

the legacy station utilizing a contention-based baseline channel access scheme;

the non-legacy stations utilizing a distributed channel time reservation access scheme;

such that performing timing-based spoofing of the legacy station allows coexistence of the channel time reservation scheme for non-legacy stations with the baseline medium access scheme for the non-legacy station in the wireless network.

16. A wireless station comprising:

a receiver that receives information in a wireless network; and

a channel access module that performs distributed channel time reservation for contention-free access to a shared wireless channel by the wireless station, based on a prior successful contention by the wireless station for access to the channel.

17. The wireless station of claim 16, wherein the channel access module is further configured such that:

the wireless station contends for access to the channel, and upon successful contention the wireless station obtains ownership of a channel time block (CTB) by reserving the CTB as a CTB-owner station for transmitting on the channel during the owned CTB, wherein the wireless station retains information about the successful contention for performing future contention-free channel reservations.

18. The wireless station of claim 17, wherein the channel access module is further configured such that:

the wireless station attempts a contention-free channel reservation based on the retained information about said successful contention.

19. The wireless station of claim 18, wherein said information about the successful contention comprises timing of said owned CTB in a specific channel time period comprising a superframe, wherein each superframe comprises multiple CTBs.

20. The wireless station of claim 19, wherein the channel access module is further configured such that:

the wireless station attempts a reservation-based channel access in a subsequent CTB within a current superframe or in a future superframe based on timing of said owned CTB within a superframe, according to the data traffic characteristics of the wireless station.

21. The wireless station of claim 19, wherein the channel access module is further configured such that:

the wireless station attempts a reservation-based channel access in a target CTB in a future superframe, the target CTB having the same relative time location as the owned CTB in the current superframe.

22. A wireless station, comprising:

a transmitter that transmits information in a wireless network; and

a channel access module that performs distributed channel time reservation for contention-free access to a wireless channel by the wireless station, based on a prior successful contention by the wireless station for access to the channel.

23. The wireless station of claim 22, wherein the channel access module is further configured such that the wireless station contends for access to the channel, and upon successful contention the wireless station obtains ownership of a channel time block (CTB) by reserving the CTB as a CTB-owner station for transmitting on the channel during the owned CTB, wherein the wireless station retains information about the successful contention for performing future contention-free channel reservations.

24. The wireless station of claim 22, wherein the channel access module is further configured such that the wireless station attempts a contention-free channel reservation based on the retained information about said successful contention, and wherein said information about the successful contention comprises timing of said owned CTB in a specific channel time period comprising a superframe, such that each superframe comprises multiple CTBs.

25. The wireless station of claim 24, wherein the channel access performs distributed CTB reservation by timing-based spoofing of a legacy wireless station to protect the owned CTB as reserved by the CTB-owner station from access by the legacy station.

26. The wireless station of claim 25, wherein:

the legacy station utilizes a contention-based baseline channel access scheme;

the CTB-owner station as a non-legacy station utilizes a distributed channel time reservation access scheme;

such that performing timing-based spoofing of the legacy station allows coexistence of the channel time reservation scheme for the CTB-owner station with the baseline medium access scheme for the legacy station in the wireless network.

27. The wireless station of claim 26, wherein the CTB-owner wireless station transmits a spoofing signal during a specific period ahead of its CTB start time, to set an appropriate access prohibition timer at the legacy station such that the legacy station cannot gain channel access in the owned CTB and within a transmit opportunity time limit before the CTB, until the timer expires.

28. A method for receiving information in a wireless network including multiple wireless stations, the method comprising:

receiving information in the wireless network using distributed channel time reservation for contention-free access to a wireless channel by each wireless station, based on a prior successful contention by the wireless station for access to the channel in the wireless network.

29. The method of claim 28 wherein said distributed channel time reservation comprises:

a wireless station contending for access to the channel;

upon successful contention, the wireless station obtaining ownership of a channel time block (CTB) by reserving the CTB as a CTB-owner station for transmitting on the channel during the owned CTB; and

the wireless station retaining information about the successful contention for performing future contention-free channel reservations.

30. The method of claim 29 further comprising:

the wireless station attempting a contention-free channel reservation based on the retained information about said successful contention.

31. The method of claim 30, wherein said information about the successful contention comprises timing of said owned CTB in a specific channel time period comprising a superframe, wherein each superframe comprises multiple CTBs.

32. The method of claim 31, wherein attempting a contention-free channel reservation based on said retained information comprises:

the wireless station attempting a reservation-based channel access in a subsequent CTB within a current superframe or in a future superframe based on timing of said owned CTB within a superframe, according to the data traffic characteristics of the wireless station.

33. The method of claim 31, wherein attempting a contention-free channel reservation based on the retained information comprises:

the wireless station attempting a reservation-based channel access in a target CTB in a future superframe, the target CTB having the same relative time location as the owned CTB in the current superframe.

34. The method of claim 31 wherein attempting a contention-free channel reservation based on the retained information comprises:

the wireless station entering an assessment stage for;

determining if its transmissions during a target CTB may cause interference to any existing CTB-owner station of the target CTB in an upcoming superframe; and

determining if its transmissions during a target CTB may cause interference to any existing CTB-owner station of the target CTB in an upcoming CTB in the current superframe.

35. The method of claim 28, further comprising performing said distributed channel time block reservation in the absence of a network coordinator.

36. A computer program product for transmitting information in a wireless network including multiple wireless stations, the computer program product comprising:

a non-transitory computer useable medium having computer readable program code embodied therewith, wherein the computer readable program when executed on the computer causes the computer to;

transmit information in the wireless network using distributed channel time reservation for contention-free access to a wireless channel by each wireless station, based on a prior successful contention by the wireless station for access to the channel in the wireless network.

37. The computer program product of claim 36 wherein said distributed channel time reservation comprises:

a wireless station contending for access to the channel;

upon successful contention, the wireless station obtaining ownership of a channel time block (CTB) by reserving the CTB as a CTB-owner station for transmitting on the channel during the owned CTB; and

the wireless station retaining information about the successful contention for performing future contention-free channel reservations.

38. A computer program product for receiving information in a wireless network including multiple wireless stations, the computer program product comprising:

a non-transitory computer useable medium having computer readable program code embodied therewith, wherein the computer readable program when executed on the computer causes the computer to;

receive information in the wireless network using distributed channel time reservation for contention-free access to a wireless channel by each wireless station, based on a prior successful contention by the wireless station for access to the channel in the wireless network.

39. The computer program product of claim 38 wherein said distributed channel time reservation comprises:

a wireless station contending for access to the channel;

upon successful contention, the wireless station obtaining ownership of a channel time block (CTB) by reserving the CTB as a CTB-owner station for transmitting on the channel during the owned CTB; and

the wireless station retaining information about the successful contention for performing future contention-free channel reservations.