Methods for controlling shared access to wireless transmission systems and increasing throughput of the same

• US 20020045428A1
• Filed: 04/20/2001
• Published: 04/18/2002
• Est. Priority Date: 04/22/2000
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Atheros Communications Incorporated (Qualcomm, Inc.)
• Inventors: Chesson, Gregory Lawrence
• Granted Patent: US 6,795,407 B2
• Time in Patent Office: Days
• US Class Current: 455/127.1
• CPC Class Codes: H04L 1/18 Automatic repetition systems, e.g. Van Duuren systems
• CPC Class Codes: H04W 52/34 TPC management, i.e. sharing limited amount of power among users or channels or data types, e.g. cell loading
• CPC Class Codes: H04W 52/346 distributing total power among users or channels
• CPC Class Codes: H04W 52/50 at the moment of starting communication in a multiple access environment
• CPC Class Codes: H04W 74/006 in the downlink, i.e. towards the terminal
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals

Abstract

A wireless communication system implements a calibration mode by which individual nodes in the system can determine which other nodes in the system are physically close to them and therefore can be reached with less than full transmitting power. Nodes which can communicate with one another via low power can form a low power constellation (a subset of the complete network) whose nodes can communicate directly with one another using this low power arrangement. The direct communication mode may additionally be used by itself. In another mode, the nodes in the system can communicate amongst themselves via bridges—other, non-access point nodes—to lessen the load on the access point or to accommodate environmental or other conditions. Various ones of these modes may be combined into a predetermined cycle of communication modes to help the physical layer accommodate various types of data handled by the network using beacons or another coordinating technique. Overhead in the form of packet retransmission may be reduced by interpolating to recover lost packets rather than retransmitting them.

Claims

1. A method of providing transmit power control calibration between a plurality of wireless stations in a multi-carrier communication system that supports both overlaid communications in which less than all available carriers can be used for transmissions and non-overlaid communications in which all available carriers can be used for transmissions, comprising the steps of:

providing a non-overlaid start signal to the plurality of wireless stations, indicating a following non-overlaid data communication period;

providing an overlaid start signal to the plurality of wireless stations, indicating a following overlaid data communication period; and

repeating the transmission of each of the non-overlaid and overlaid start signals, thereby providing for certain periods during which non-overlaid data communications takes place and other periods during which overlaid data communications takes place.

2. The method according to claim 1 further including the steps of:

providing a non-overlaid end signal to the plurality of wireless stations, indicating an end to the previous non-overlaid data communication period; and

providing an overlaid end signal to the plurality of wireless stations, indicating an end to the previous overlaid data communication period.

3. The method according to claim 2 wherein the non-overlaid end signal and the overlaid end signal are IEEE 802.11 beacon signals.

4. The method according to claim 2 wherein the step of providing the non overlaid end signal includes providing a header pattern uniquely identifying the non-overlaid end signal.

5. The method according to claim 4 wherein the step of providing the non overlaid end signal includes providing a length of time after which another non-overlaid data communication period will occur.

6. The method according to claim 2 wherein each of the steps of providing is performed by a base station.

7. The method according to claim 2 wherein each of the steps of providing is performed by a designated coordinating node.

8. The method according to claim 2 wherein each of the steps of providing is performed by a plurality of nodes in an ad hoc network.

9. The method according to claim 2 wherein the step of providing the non overlaid start signal includes providing a header pattern uniquely identifying the non-overlaid start signal.

10. The method according to claim 9 wherein the step of providing the non overlaid start signal includes providing a length of time during which the following non-overlaid data communication period will last.

11. The method according to claim 9 wherein the step of providing the non overlaid start signal includes providing a begin time and an end time for the following non-overlaid data communication period.

12. The method according to claim 2 wherein the step of providing the overlaid start signal includes providing a header pattern uniquely identifying the overlaid start signal.

13. The method according to claim 12 wherein the step of providing the overlaid start signal includes providing a plurality of carrier assignments identifying which carriers each of the plurality of wireless stations can transmit on during the following overlaid data communication period.

14. The method according to claim 13 wherein the step of providing the overlaid start signal includes providing a length of time during which the following overlaid data communication period will last.

15. The method according to claim 12 wherein the step of providing the overlaid start signal includes providing a length of time during which the following overlaid data communication period will last.

16. The method according to claim 12 wherein the step of providing the overlaid start signal includes providing time slot assignments indicating when during the following overlaid communication period each of the wireless stations can transmit.

17. The method according to claim 16 wherein the step of providing the time slot assignments provides each assignment only on at least one carrier necessary for overlaid communications to take place with respect to at least that one carrier.

18. The method according to claim 12 wherein the step of providing the overlaid start signal includes providing one of a plurality of polling signals indicating that the following overlaid communication period should begin for a respective one of the plurality of wireless stations can transmit.

19. The method according to claim 2 wherein during the non-overlaid communication period, only one of the plurality of wireless stations transmits on all available carriers at any given time during the non-overlaid communication period.

20. The method according to claim 1 wherein each of the steps of providing is performed by a base station.

21. The method according to claim 1 wherein each of the steps of providing is performed by a designated coordinating node.

22. The method according to claim 1 wherein each of the steps of providing is performed by a plurality of nodes in an ad hoc network.

23. The method according to claim 1 wherein the step of providing the non overlaid start signal includes providing a header pattern uniquely identifying the non-overlaid start signal.

24. The method according to claim 23 wherein the step of providing the non overlaid start signal includes providing a length of time during which the following non-overlaid data communication period will last.

25. The method according to claim 23 wherein the step of providing the non overlaid start signal includes providing a begin time and an end time for the following non-overlaid data communication period.

26. The method according to claim 23 wherein the step of providing the overlaid start signal includes providing a header pattern uniquely identifying the overlaid start signal.

27. The method according to claim 26 wherein the step of providing the overlaid start signal includes providing a plurality of carrier assignments identifying which carriers each of the plurality of wireless stations can transmit on during the following overlaid data communication period.

28. The method according to claim 27 wherein the step of providing the overlaid start signal includes providing a length of time during which the following overlaid data communication period will last.

29. The method according to claim 26 wherein the step of providing the overlaid start signal includes providing a length of time during which the following overlaid data communication period will last.

30. The method according to claim 23 wherein the step of providing the overlaid start signal includes providing time slot assignments indicating when during the following overlaid communication period each of the wireless stations can transmit.

31. The method according to claim 30 wherein the step of providing the time slot assignments provides each assignment only on at least one carrier necessary for overlaid communications to take place with respect to at least that one carrier.

32. The method according to claim 23 wherein the step of providing the overlaid start signal includes providing one of a plurality of polling signals indicating that the following overlaid communication period should begin for a respective one of the plurality of wireless stations can transmit.

33. The method according to claim 1 wherein during the non-overlaid communication period, only one of the plurality of wireless stations transmits on all available carriers at any given time during the non-overlaid communication period.

34. The method according to claim 1 wherein the step of providing the overlaid start signal includes providing a header pattern uniquely identifying the overlaid start signal.

35. The method according to claim 34 wherein the step of providing the overlaid start signal includes providing a plurality of carrier assignments identifying which carriers each of the plurality of wireless stations can transmit on during the following overlaid data communication period.

36. The method according to claim 35 wherein the step of providing the overlaid start signal includes providing a length of time during which the following overlaid data communication period will last.

37. The method according to claim 34 wherein the step of providing the overlaid start signal includes providing time slot assuagements indicating when during the following overlaid communication period each of the wireless stations can transmit.

38. The method according to claim 37 wherein the step of providing the time slot assignments provides each assignment only on at least one carrier necessary for overlaid communications to take place with respect to at least that one carrier.

39. The method according to claim 1 wherein during the non-overlaid communication period, only one of the plurality of wireless stations transmits on all available carriers at any given time during the non-overlaid communication period.

40. The method according to claim 1 wherein the step of providing the overlaid start signal includes providing one of a plurality of polling signals indicating that the following overlaid communication period should begin for a respective one of the plurality of wireless stations can transmit.

41. The method according to claim 1 wherein the non-overlaid end signal and the overlaid end signal are IEEE 802.11 beacon signals.

42. A method of establishing overlaid communications in a multi-carrier communication system between a plurality of wireless stations each capable of communicating on less than all carriers in the multi-carrier communication system comprising the steps of:

providing each of the plurality of wireless stations capable of performing overlaid communications in the multi-carrier communication system a message which includes an assigned carrier and an assigned calibration transmit power level for transmission,

allowing a period of time for each of the plurality of wireless stations to transmit at least one calibration message on the assigned carrier at the assigned calibration power level;

transmitting from each of the plurality of wireless stations at least one calibration message on the assigned carrier at the assigned calibration power level;

receiving from each of the plurality of wireless stations information indicating transmissions from other ones of the plurality of wireless stations that they received and the receive power level of each of these received transmissions.; and

using the received information to map which ones of the plurality of wireless stations can communicate with other ones of the plurality of wireless stations on assigned carriers, at a transmit power level chosen from a plurality of available transmit power levels so that subsequent signals from some of the plurality of wireless stations arriving at substantially the same time at another of the wireless stations have a substantially similar receive power level at the another wireless station.

43. The method according to claim 42 wherein the step of transmitting transmits from each of the plurality of wireless stations a plurality of calibration messages.

44. The method according to claim 43 wherein each of the plurality of calibration messages for each of the plurality of wireless stations is transmitted at different power levels.

45. The method according to claim 44 wherein each of the plurality of power calibration messages for each of the plurality of wireless stations is transmitted at increasing power levels.

46. The method according to claim 44 wherein each of the plurality of power calibration messages for each of the plurality of wireless stations is transmitted at decreasing power levels.

47. The method according to claim 42 wherein the steps of providing and receiving occur at the another wireless station.

48. The method according to claim 47 wherein the another wireless station is an access point.

49. The method according to claim 42 wherein it is determined that a first wireless station cannot communicate with a second wireless station at one of the available power levels at the same time without preventing a third wireless station from communicating.

50. The method according to claim 49 wherein it is determined that the first wireless station cannot communicate with the second wireless station at one of the available power levels at the same time without saturating the third wireless station.

51. The method according to claim 42 wherein the message further specifies the period of time.

52. The method according to claim 42 wherein the message further specifies one of a plurality of calibration periods that exist during the period of time for each of the plurality of wireless stations to transmit at on the assigned carrier and at the assigned power level.

53. The method according to claim 52 wherein each of the plurality of wireless stations transmit during the period of time the calibration message containing therein an identifier of the transmitting wireless station and a transmit power level at which the calibration message is being transmitted.

54. The method according to claim 53 wherein the received calibration message from various ones of the transmitting wireless stations is collected at each receiving wireless station and used to obtain the information during the step of receiving.

55. The method according to claim 42 wherein the step of providing the message provides the carrier assignment using a vector having a number of elements equal to a number of available carriers.

56. The method according to claim 42 further including a transmission period during which the plurality of wireless stations communicate within constraints of the map.

57. The method according to claim 56 wherein during the transmission period, at least one pair of the plurality of wireless stations communicate such that an acknowledgement after a transmission is not used.

58. The method according to claim 42 wherein during the period of time, transmissions of different calibration messages on respectively different overlaid carriers can take place at the same time.

60. The method according to claim 59 wherein the multi-carrier communication system is a non-overlaid communication system.

59. A method of establishing communications in a multi-carrier communication system between a plurality of wireless stations each capable of communicating on less than all carriers in the multi-carrier communication system comprising the steps of:

providing each of the plurality of wireless stations capable of performing communications in the multi-carrier communication system a message which includes an assigned calibration power level for transmission,

allowing a period of time for each of the plurality of wireless stations to transmit at least one calibration message at the assigned calibration power level;

transmitting from each of the plurality of wireless stations at least one calibration message on the assigned carrier at the assigned calibration power level;

receiving from each of the plurality of wireless stations information indicating transmissions from other ones of the plurality of wireless stations that they received and the receive power level of each of these received transmissions; and

using the received information to map the receive power levels and associated transmitting and receiving wireless stations.

61. A method of establishing overlaid communications in a multi-carrier communication system between a plurality of wireless stations each capable of communicating on less than all carriers in the multi-carrier communication system comprising the steps of:

providing each of the plurality of wireless stations capable of performing overlaid communications in the multi-carrier communication system a message which includes an assigned carrier and an assigned calibration transmit power level for transmission,

allowing a period of time for each of the plurality of wireless stations to transmit at least one calibration message on the assigned carrier at the assigned calibration power level;

transmitting from each of the plurality of wireless stations at least one calibration message on the assigned carrier at the assigned calibration power level;

receiving from each of the plurality of wireless stations information indicating transmissions from other ones of the plurality of wireless stations that they received and the receive power level of each of these received transmissions; and

using the received information to map which ones of the plurality of wireless stations can communicate with other ones of the plurality of wireless stations on assigned carriers without substantially interfering with further ones of the plurality of wireless stations.

62. The method according to claim 61 wherein the steps of providing and receiving occur at the another wireless station.

63. The method according to claim 62 wherein the another wireless station is an access point.

64. The method according to claim 61 wherein it is determined that a first wireless station cannot communicate with a second wireless station at one of the available power levels at the same time without preventing a third wireless station from communicating.

65. The method according to claim 64 wherein it is determined that the first wireless station cannot communicate with the second wireless station at one of the available power levels at the same time without saturating the third wireless station.

66. The method according to claim 61 wherein each of the plurality of wireless stations transmit during the period of time the calibration message containing therein an identifier of the transmitting wireless station and a transmit power level at which the calibration message is being transmitted.

67. The method according to claim 61 wherein the received calibration message from various ones of the transmitting wireless stations is collected at each receiving wireless station and used to obtain the information during the step of receiving.

68. The method according to claim 61 further including a transmission period during which the plurality of wireless stations communicate within constraints of the map.

69. The method according to claim 68 wherein during the transmission period, at least one pair of the plurality of wireless stations communicate such that an acknowledgement after a transmission is not used.