Method and system for wirelessly transmitting data between a base transceiver station and a subscriber unit

• US 20020183067A1
• Filed: 06/01/2001
• Published: 12/05/2002
• Est. Priority Date: 06/01/2001
• Status: Abandoned Application

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Mishra, Partho, Airy, Manish, Stojanovic, Ivana, Saran, Huzur
• Application Number:
  US09/870,706
• Publication Number:
  US 20020183067A1
• Time in Patent Office: Days
• US Class Current: 455/455
• CPC Class Codes: H04L 1/1887 Scheduling and prioritising arrangements
• CPC Class Codes: H04L 2001/0093 Point-to-multipoint
• CPC Class Codes: H04W 74/08 Non-scheduled access, e.g. ALOHA hybrid access H04W74/02

Abstract

The present invention includes a method and system for wirelessly transmitting data between a plurality of subscriber units and a base transceiver station. The method comprises at least one subscriber unit transmitting a service flow request to the base transceiver station, determining if the service flow request was received by the base transceiver station, utilizing a back-off algorithm to re-transmit the service flow request if the service flow request was not received by the base transceiver station and transmitting data blocks to the base transceiver station based on the service flow request. The system comprises a base transceiver station and a subscriber unit, the subscriber unit comprising means for transmitting a service flow request to the base transceiver station means for determining if the service flow request was received by the base transceiver station, means for utilizing a back-off algorithm to re-transmit the service flow request if the service flow request was not received by the base transceiver station and means for transmitting data blocks to the base transceiver station based on the service flow request.

Claims

1. A method for wirelessly transmitting data between a plurality of subscriber units and a base transceiver station, the method comprising:

at least one subscriber unit transmitting a service flow request to the base transceiver station;

determining if the service flow request was received by the base transceiver station;

utilizing a back-off algorithm to re-transmit the service flow request if the service flow request was not received by the base transceiver station; and

transmitting data blocks to the base transceiver station based on the service flow request.

2. The method of claim 1 wherein determining if the service flow request was received by the base transceiver station comprises:

determining if the base transceiver station is backlogged; and

determining if the base transceiver station is slow in processing or if a scheduler is overloaded if the base transceiver station is backlogged.

3. The method of claim 2 wherein the base transceiver station is backlogged if a last frame processed is less than the frame number in which the service flow request was sent.

4. The method of claim 2 wherein the at least one subscriber unit receives an allocation pending indication if the scheduler is overloaded.

5. The method of claim 1 wherein the request is transmitted via a contention channel of a data frame.

6. The method of claim 5 wherein the back-off algorithm comprises:

adjusting a contention window;

calculating a back-off time based on the adjusted contention window; and

re-transmitting the service flow request based on the back-off time.

7. The method of claim 6 wherein adjusting the contention window comprises multiplying a current contention window by two.

8. The method of claim 6 wherein the contention window comprises a minimum value and a maximum value wherein the minimum value and maximum value can be changed.

9. The method of claim 6 wherein calculating the back-off time comprises randomly selecting a number between 1 and the adjusted contention window.

10. The method of claim 9 wherein re-transmitting the service flow request based on the back-off time comprises:

waiting for a predetermined number of transmission opportunities; and

re-transmitting the service flow request at the next transmission opportunity.

11. The method of claim 10 wherein a transmission opportunity comprises a contention block within a frame.

12. The method of claim 11 wherein the number of contention blocks in each frame is variable.

13. The method of claim 10 wherein the predetermined number of transmission opportunities is equal to the randomly selected number between 1 and the adjusted contention window.

14. The method of claim 1 further comprising polling the at least one subscriber unit if the at least one subscriber unit is in a polling mode.

15. The method of claim 14 wherein if the at least one subscriber unit is in the polling mode, the at least one subscriber unit may not transmit a service flow request over the contention channel.

17. The method of claim 16 wherein the base transceiver station is backlogged if a last frame processed is less than the frame in which the request was sent.

18. The method of claim 17 further comprising:

transmitting an allocation pending indication to the subscriber unit if the scheduler is overloaded.

19. The method of claim 17 wherein the service flow request is transmitted via a contention channel of a data frame.

20. The method of claim 19 wherein the number of contention blocks in each frame is variable.

21. The method of claim 16 further comprising polling the subscriber unit over a period of time if the subscriber unit is in a polling mode.

22. The method of claim 21 wherein the base transceiver station indicates allocations in the scheduler for subscriber units that are in the polling mode.

23. The method of claim 22 wherein the period of time is variable.

25. The system of claim 24 wherein the means for determining if the service flow request was received by the base transceiver station comprises:

means for determining if the base transceiver station is backlogged; and

means for determining if the base transceiver station is slow in processing or if a scheduler is overloaded if the base transceiver station is backlogged.

26. The system of claim 25 wherein the base transceiver station is backlogged if a last frame processed is less than the frame number in which the service flow request was sent.

27. The system of claim 25 wherein the at least one subscriber unit receives an allocation pending indication if the scheduler is overloaded.

28. The system of claim 25 wherein the service flow request is transmitted via a contention channel of a data frame.

29. The system of claim 28 wherein the means for utilizing a back-off algorithm comprises:

means for adjusting a contention window;

means for calculating a back-off time based on the adjusted contention window; and

means for re-transmitting the service flow request based on the back-off time.

30. The system of claim 29 wherein adjusting the contention window comprises multiplying a current contention window by two.

31. The system of claim 29 wherein the contention window comprises a minimum value and a maximum value wherein the minimum value and maximum value can be changed.

32. The system of claim 29 wherein the means for calculating the back-off time comprises means for randomly selecting a number between 1 and the adjusted contention window.

33. The system of claim 32 wherein the means for re-transmitting the service flow request based on the back-off time comprises:

means for waiting for a predetermined number of transmission opportunities; and

means for re-transmitting the service flow request at the next transmission opportunity.

34. The system of claim 33 wherein a transmission opportunity comprises a contention block within a frame.

35. The system of claim 34 wherein the number of contention blocks in each frame is variable.

36. The system of claim 33 wherein the predetermined number of transmission opportunities is equal to the randomly selected number between 1 and the adjusted contention window.

37. The system of claim 25 further comprising means for polling the at least one subscriber unit if the at least one subscriber unit is in a polling mode

39. The system of claim 38 wherein the base transceiver station is backlogged if a last frame processed is less than the frame in which the request was sent.

40. The system of claim 39 further comprising:

means for transmitting an allocation pending indication to the subscriber unit if the scheduler is overloaded.

41. The system of claim 39 wherein the service flow request is transmitted via a contention channel of a data frame.

42. The system of claim 41 wherein the number of contention blocks in each frame is variable.

43. The system of claim 38 wherein the base transceiver station further comprises means for polling the subscriber unit over a period of time if the subscriber unit is in a polling mode.

44. The system of claim 43 wherein the base transceiver station further comprises means for indicating allocations in the scheduler for subscriber units that are in the polling mode.

16. A method for wirelessly transmitting data between a plurality of subscriber units and a base transceiver station, the method comprising:

the base transceiver station receiving a service flow request from a subscriber unit;

determining if the base transceiver station is backlogged; and

determining if the base transceiver station is slow in processing or if a scheduler is overloaded if the base transceiver station is backlogged.

24. A system for wirelessly transmitting data the system comprising:

a base transceiver station; and

a subscriber unit, the subscriber unit comprising;

means for transmitting a service flow request to the base transceiver station;

means for determining if the service flow request was received by the base transceiver station;

means for utilizing a back-off algorithm to re-transmit the service flow request if the request was not received by the base transceiver station; and

means for transmitting data blocks to the base transceiver station based on the service flow request.

38. A system for wirelessly transmitting data the system comprising:

a subscriber unit; and

a base transceiver station, the base transceiver station comprising;

means for receiving a service flow request from the subscriber unit;

means for determining if the base transceiver station is backlogged; and

means for determining if the base transceiver station is slow in processing or if a scheduler is overloaded if the base transceiver station is backlogged.