Scalable association scheme for TV white-space MIMO wireless system

• US 8,396,086 B1
• Filed: 09/30/2009
• Issued: 03/12/2013
• Est. Priority Date: 09/30/2009
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Google Inc. (Alphabet Inc.)
• Inventors: Gossett, Carroll Philip, Yuan, Yuan, Yu, Kevin C., Gunter, Michial Allen, Koukoumidis, Emmanouil, Jiang, Xiaofang
• Primary Examiner(s): Thier, Michael
• Assistant Examiner(s): Elliott, IV, Benjamin H
• Application Number:
  US12/570,866
• Time in Patent Office: 1,259 Days
• Field of Search: 370/342, 370/376, 370/236, 370/280, 370/314, 370/328, 370/334, 370/458, 370/461, 370/508, 340/3.21, 379/93.32, 709/237
• US Class Current: 370/508
• CPC Class Codes: H04B 7/0413 MIMO systems
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 74/08 Non-scheduled access, e.g. ALOHA hybrid access H04W74/02

Abstract

A computer-implemented method may include receiving at a wireless device one or more beacon packets sent by a communication base station, determining a delay period at the wireless device, wherein the delay period is determined so that a delay for the wireless device is different than a delay for another wireless device, sending a first association request from the wireless device after waiting for the delay period, and establishing communication with the base station if an association response is received from the base station within a determined time period. The first association request may include information identifying the wireless device and an association code.

Claims

1. A computer-implemented method for establishing electronic communications, comprising:

receiving at a first wireless device one or more beacon packets sent by a communication base station;

determining a delay period at the first wireless device, wherein the delay period is determined so that a delay for the first wireless device is different than a delay for a second wireless device;

sending a first association request from the first wireless device after waiting for the delay period, wherein the first association request includes information identifying the first wireless device and an association code;

receiving an association response from the communication base station within a determined time period, wherein the association response includes an identifier for a static slot of a repeating frame structure and an identifier for a static uplink sub-slot within the static slot, the static uplink sub-slot being designated for transmissions from the first wireless device to the communication base station; and

in response to receiving an association response from the communication base station within the determined time period, establishing communication with the communication base station.

2. The method of claim 1, wherein the one or more beacon packets identify the association code for the communication base station.

3. The method of claim 2, wherein the association code includes a code that identifies an antenna on the communication base station for communicating with the communication base station.

4. The method of claim 1, further comprising receiving, at the first wireless device, beacon packets from a plurality of different base stations, wherein the beacon packets sent by each base station include one or more association codes that are distinct from association codes received from the other base stations, and selecting one of the association codes in preference to the other association codes.

5. The method of claim 4, wherein selecting the one of the association codes in preference to the other association codes comprises selecting the association code from a base station having a highest signal strength at the first wireless device.

6. The method of claim 4, wherein selecting the one of the association codes in preference to the other association codes comprises selecting the association code from a base station having a highest level of available resources.

7. The method of claim 4, wherein selecting the one of the association codes in preference to the other association codes comprises selecting the one of the association codes randomly.

8. The method of claim 1, wherein the static uplink sub-slot is designated for transmissions from the first wireless device to the communication base station in each of multiple consecutive repetitions of the repeating frame structure.

9. The method of claim 1, further comprising using data stored on the first wireless device to identify a position for the static uplink sub-slot in the repeating frame structure.

10. The method of claim 1, further comprising:

identifying the repeating frame structure for communication between the first wireless device and the communication base station, the repeating frame structure including a plurality of slots, with each slot including an uplink portion and a downlink portion, and each uplink portion and downlink portion comprising a plurality of sub-slots;

obtaining by the first wireless device a sub-slot in an uplink portion of a static slot in the frame structure, to the exclusion of other wireless computing devices, wherein

the sub-slot is associated with the first wireless device throughout a communication session, and

each sub-slot in the uplink portion that is assigned to a wireless device is assigned to a wireless device distinct from wireless devices to which each of the other sub-slots in the uplink portion are assigned.

11. The method of claim 1, wherein receiving at the first wireless device one or more beacon packets sent by the communication base station comprises receiving, at the wireless device, the beacon packets from the communication base station and beacon packets for a plurality of neighboring base stations, wherein the one or more beacon packets sent by the communication base station identify a first code set that comprises multiple codes, the first code set being different from association code sets for the one or more neighboring base stations;

wherein sending the first association request from the first wireless device after waiting for the delay period comprises;

accessing, at the first wireless device, data stored at the wireless device before receiving a beacon packet sent by the communication base station, the accessed data identifying the multiple association codes in the first code set, the multiple association codes respectively identifying different antennas of the communication base station;

sending one of the multiple association codes in the first code set as the association code, the association code identifying an antenna on the communication base station for communicating with the communication base station.

12. The method of claim 1, wherein the delay period is randomly selected by the wireless device from among a set of delay period, and wherein the association response identifies a propagation delay for the client device inferred by the communication base station based on the association request.

13. The method of claim 1, wherein establishing communication with the communication base station if an association response is received from the communication base station within a determined time period comprises:

receiving the association response from the communication base station within the determined time period; and

transmitting data to the communication base station using a code having a first processing gain;

wherein sending the first association request comprises sending the first association request on a reserved code with a processing gain higher than the first processing gain.

14. The method of claim 13, wherein transmitting data to the communication base station comprises transmitting data to the communication base station at a first power level;

wherein sending the first association request comprises sending the first association request at a power level lower than the first power level.

15. The method of claim 1, further comprising:

randomly selecting a slot within a first contention window, the delay period being a delay until the beginning of the randomly selected slot;

sending, by the first wireless device, a second association request to a second base station during the randomly selected slot of the first contention window;

determining that an association response to the second association request is not received within a timeout period;

in response to determining that an association response to the second association request is not received within a timeout period;

determining a size of a second contention window, the size of the second contention window being twice a size of the first contention window;

randomly selecting a second slot within the second contention window; and

sending a second association request to the communication base station during the randomly selected second slot of the second contention window.

16. The method of claim 1, further comprising:

selecting a slot within a first contention window;

sending, by the first wireless device, a second association request to a second base station during the randomly selected slot of the first contention window;

determining that an association response to the second association request is not received within the timeout period; and

after determining that an association response to the second association request is not received within the time period, sending multiple association requests to the second communication base station, each of the multiple association requests being sent during a slot selected from a different contention window, each of the different contention windows being larger than the contention window during which the immediately previous association request was sent by the wireless device to the communication base station.

17. The method of claim 16, wherein sending multiple association requests to the communication base station comprises sending association requests to the second communication base station in randomly selected slots of contention windows of increasing sizes until the contention window reaches a predetermined maximum contention window size,

wherein the method further comprises, after the contention window reaches the predetermined maximum contention window size, sending association requests to the second communication base station in randomly selected slots of contention windows having the maximum contention window size until an association response is received from the second communication base station within a corresponding timeout period or after a predetermined number of association requests have been sent.

18. An electronic communications device comprising:

one or more computer processors;

memory in electronic communications with the one or more processors and storing instructions that, when executed, perform actions comprising;

identifying one or more beacon packets received over a wireless connection by the electronic communications device;

determining a delay period so that a delay for the electronic communications device is different than a delay for electronic communications devices in a common cell with the electronic communications device;

after waiting for the delay period, sending a first association request that includes information identifying the electronic communication device and an association code;

receiving an association response from a target communication device within a determined time period, wherein the association response includes an identifier for a static slot of a repeating frame structure and an identifier for a static uplink sub-slot within the static slot, the static uplink sub-slot being designated for transmissions from the electronic communications device to the target communication device; and

in response to receiving an association response from the target communication device within the determined time period, establishing communication with the target communication device.

19. The device of claim 18, wherein the one or more beacon packets identify the association code for the target communication device.

20. The device of claim 19, wherein the association code includes a code that identifies an antenna on the target communication device for communicating with the target communication device.

21. The device of claim 18, wherein the actions further comprise receiving, at the electronic communication device, beacon packets from a plurality of different target communication devices, wherein the beacon packets sent by each target communication device include one or more association codes that are distinct from association codes received from the other target communication devices, and selecting one of the association codes in preference to the other association codes.

22. The device of claim 21, wherein selecting the one of the association codes in preference to the other association codes comprises selecting the association code from a target communication device having a highest signal strength at the electronic communication device.

23. The device of claim 21, wherein selecting the one of the association codes in preference to the other association codes comprises selecting the one of the association codes randomly from among a set of association codes for the communication base station that is different from sets of association codes for other communication base stations, each of the association codes in the set of association codes identifying an antenna on the target communication device for communicating with the target communication device.

24. The device of claim 18, wherein the static uplink sub-slot is designated for transmissions from the first wireless device to the communication base station in each of multiple consecutive repetitions of the repeating frame structure.

25. The device of claim 18, wherein the actions further comprise using data stored on the electronic communication device to identify a position for the static uplink sub-slot in the repeating frame structure.