Spatial reuse in a wireless communications network

• US 7,519,013 B2
• Filed: 06/30/2005
• Issued: 04/14/2009
• Est. Priority Date: 06/30/2005
• Status: Expired due to Fees

• Current Assignee: Nokia Corporation
• Original Assignee: Nokia Corporation
• Inventors: Kaaja, Harald, Destino, Giuseppe, Reunamaki, Jukka, Celentano, Ulrico, Goratti, Leonardo
• Primary Examiner(s): Ly; Nghi H
• Application Number:
  US11/170,116
• Publication Number:
  US 20070002803A1
• Time in Patent Office: 1,384 Days
• Field of Search: 370/310, 370/328, 370/338, 370/329, 455/450, 455/52.14, 455/522
• US Class Current: 370/310
• CPC Class Codes: H04W 72/543 based on requested quality, e.g. QoS

Abstract

The present invention provides techniques for spatial reuse in wireless communications networks. Accordingly, the present invention provides A device participates in a wireless communications network. The network has a shared transmission medium for the exchange of communications traffic. Further, the device determines a value for at least one interference condition in the shared transmission medium of the wireless communications network. Based on this value, a planned transmission to a remote wireless communications device is scheduled. For instance, when this value is less than a predetermined threshold, this scheduling employs a time-overlapping access technique.

Claims

1. A method, comprising:

(a) participating with a first wireless device in a wireless communications network of a plurality of wireless devices including the first wireless device and a plurality of other wireless devices, having a shared transmission medium for the exchange of communications traffic between the wireless devices in the network, by each device in the network transmitting and receiving beacon transmissions that maintain coordination between the plurality of wireless devices in the wireless communication network and provide information regarding resource allocations for the shared transmission medium;

(b) determining at the first wireless device a value for at least one interference condition in the shared transmission medium of the wireless communications network between said first wireless device and one of said other wireless devices in the network, wherein the value of the interference condition is determined at least partly based on the received beacon transmissions at the first wireless device; and

(c) scheduling with the first wireless device a planned transmission to said one of said other wireless devices in the network, wherein said scheduling step employs a time-overlapping access technique for the planned transmission when the value for the at least one interference condition is less than a predetermined threshold and employs a non-concurrent access technique for the planned transmission when the value for the at least one interference condition is greater than or equal to the predetermined threshold.

2. The method of claim 1, wherein the at least one interference condition is from the perspective of the one of said other wireless communications devices.

3. The method of claim 1, wherein said determining step is based on locality information of one or more devices in the wireless communications network.

4. The method of claim 1, wherein said determining step is further based on planned transmissions of the one or more devices in the wireless communications network.

5. The method of claim 1, further comprising:

detecting the at least one interference condition.

6. The method of claim 1, further comprising:

when the scheduling step employs the time-overlapping access technique, transmitting the planned transmission to the one of said other wireless devices at a time alignment that overlaps with one or more other transmissions in the wireless communications network.

7. The method of claim 6, wherein the transmitting step includes transmitting the planned transmission to the one of said other wireless devices at a reduced power level when the scheduling step employs the time-overlapping access technique.

8. The method of claim 1, further comprising:

gathering a plurality of signal strength indicators, each signal strength indicator associated with a transmission from a corresponding device in the wireless communications network;

wherein said determining step determines the value for the at least one interference condition based on the plurality of signal strength indicators.

9. The method of claim 8, wherein the plurality of signal strength indicators includes a first indicator corresponding to a transmission from the one of said other wireless communications devices, and a second signal strength indicator, the second signal strength indicator having the largest magnitude of the plurality of signal strength indicators;

and

wherein step (b) comprises comparing the first and second signal strength indicators.

10. The method of claim 8, wherein step (b) comprises from the plurality of signal strength indicators, calculating a total interference level for the one of said other wireless communications devices.

11. The method of claim 8, wherein each received transmission is a beacon transmission.

12. The method of claim 1, wherein the shared transmission medium includes a repeating time interval within a predetermined frequency range.

13. The method of claim 1, further comprising:

gathering a plurality of distance indicators, each distance indicator representing a physical distance between a respective device pairing in the wireless communications network;

wherein said determining step determines the value for the at least one interference condition based on the plurality of distance indicators.

14. The method of claim 1, further comprising determining a level of network availability;

wherein steps (c) and (d) are bypassed when the level of network availability is greater than a predetermined amount.

15. An apparatus, comprising:

a transceiver configured to exchange signals across a wireless communications network, the wireless communications network of a plurality of wireless devices including the apparatus and a plurality of other wireless devices, having a shared transmission medium for the exchange of communications traffic between the wireless devices in the network, by each device in the network transmitting and receiving beacon transmissions that maintain coordination between the plurality of wireless devices in the wireless communication network and provide information regarding resource allocations for the shared transmission medium;

a controller configured to;

(a) determine a value for at least one interference condition in the shared transmission medium of the wireless communications network between said apparatus and one of said other wireless devices in the network, wherein the value of the interference condition is determined at least partly based on the received beacon transmissions at the apparatus, and

(b) schedule a planned transmission to said one of said other wireless devices in the network, wherein said scheduling employs a time-overlapping access technique for the planned transmission when the value for the at least one interference condition is less than a predetermined threshold and employs a non-concurrent access technique for the planned transmission when the value for the at least one interference condition is greater than or equal to the predetermined threshold.

16. The apparatus of claim 15, further comprising a storage medium configured to store locality information regarding a plurality of devices, wherein the controller is configured to determine the value for the at least one interference condition based on the locality information.

17. The apparatus of claim 16, wherein the locality information includes a plurality of signal strength indicators, each signal strength indicator associated with a transmission from a corresponding device in the wireless communications network.

18. The apparatus of claim 17, wherein the plurality of signal strength indicators includes a first indicator corresponding to a transmission from the one of said other wireless communications devices, and a second signal strength indicator, the second signal strength indicator having the largest magnitude of the plurality of signal strength indicators;

and

wherein the controller is configured to assess the at least one interference condition by comparing the first and second signal strength indicators.

19. The apparatus of claim 17, wherein the controller is configured to determine the value for the at least one interference condition by calculating a total interference level from the plurality of signal strength indicators.

20. The apparatus of claim 16, wherein the locality information includes a plurality of distance indicators, each distance indicator representing a physical distance between a respective device pairing in the wireless communications network.

21. The apparatus of claim 15, wherein the shared transmission medium includes a repeating time interval within a predetermined frequency range.

22. An apparatus, comprising:

means for participating with a first wireless device in a wireless communications network of a plurality of wireless devices including the first wireless device and a plurality of other wireless devices, having a shared transmission medium for the exchange of communications traffic between the wireless devices in the network, by each device in the network transmitting and receiving beacon transmissions that maintain coordination between the plurality of wireless devices in the wireless communication network and provide information regarding resource allocations for the shared transmission medium;

means for determining at the first wireless device a value for at least one interference condition in the shared transmission medium of the wireless communications network between said first wireless device and one of said other wireless devices in the network, wherein the value of the interference condition is determined at least partly based on the received beacon transmissions at the first wireless device; and

means for scheduling with the first wireless device a planned transmission to said one of said other wireless device in the network, wherein said scheduling step employs a time-overlapping access technique for the planned transmission when the value for the at least one interference condition is less than a predetermined threshold and employs a non-concurrent access technique for the planned transmission when the value for the at least one interference condition is greater than or equal to the predetermined threshold.

23. A computer readable storage medium, comprising:

said computer readable storage medium containing computer executable instructions for enabling a processor in a first wireless device;

program code in the computer readable storage medium, for enabling the processor to cause the first wireless device to participate in a wireless communications network of a plurality of wireless devices including the first wireless device and a plurality of other wireless devices, having a shared transmission medium for the exchange of communications traffic between the wireless devices in the network, by each device in the network transmitting and receiving beacon transmissions that maintain coordination between the plurality of wireless devices in the wireless communication network and provide information regarding resource allocations for the shared transmission medium;

program code in the computer readable storage medium, for enabling the processor to determine a value for at least one interference condition in the shared transmission medium of the wireless communications network between said first wireless device and one of said other wireless devices in the network, wherein the value of the interference condition is determined at least partly based on the received beacon transmissions at the first wireless device; and

program code in the computer readable storage medium, for enabling the processor to schedule a planned transmission to said one of said other wireless devices in the network, wherein said scheduling step employs a time-overlapping access technique for the planned transmission when the value for the at least one interference condition is less than a predetermined threshold and employs a non-concurrent access technique for the planned transmission when the value for the at least one interference condition is greater than or equal to the predetermined threshold.

24. A method, comprising:

(a) receiving at a first wireless device in a group a plurality of beacon messages from a plurality of other wireless devices in the group across a wireless transmission medium, wherein the beacon messages are for maintaining coordination between wireless devices in the group, the beacon messages including a first value for a first interference condition between at least two of said plurality of other wireless devices in the group, wherein the value of the first interference condition is determined at least partly based on received beacon transmissions at one of said two of said plurality of other wireless devices;

(b) determining at the first wireless device a second value for a second interference condition between said first wireless device and said one of said two of said plurality of other wireless devices in the group, wherein the second value of the second interference condition is determined at least partly based on the received beacon transmissions at the first wireless device; and

(c) sending by the first wireless device in a beacon message to said plurality of other wireless devices in the group, an announcement scheduling a planned transmission between said first wireless device and said one of said two of said plurality of other wireless devices in the group, wherein said scheduling employs a time-overlapping access technique for the planned transmission when a comparison of said first value and second value is less than a predetermined threshold.

25. A method, comprising:

(a) participating with a first wireless device in a wireless communications network of the first wireless device and a plurality of other wireless devices, having a shared transmission medium for the exchange of communications traffic between the wireless devices in the network, by each device in the network transmitting and receiving beacon transmissions that maintain coordination between the plurality of wireless devices in the wireless communication network and provide information regarding resource allocations for the shared transmission medium, the beacon transmissions including a first value for a first interference condition between two of said plurality of other wireless devices in the network, wherein the value of the first interference condition is determined at least partly based on received beacon transmissions at one of said two other wireless devices;

(b) determining at the first wireless device a second value for a second interference condition in the shared transmission medium of the wireless communications network between said first wireless device and said one of said two other wireless devices in the network, wherein the value of the second interference condition is determined at least partly based on the received beacon transmissions at the first wireless device; and

(c) sending by the first wireless device in a beacon transmission to said plurality of other wireless devices in the network, an announcement scheduling a planned transmission to said one of said two other wireless devices in the network, wherein said scheduling employs a time-overlapping access technique for the planned transmission when a comparison of said first value and second value is is less than a predetermined threshold.

26. A method, comprising:

(a) participating with a first wireless device in a wireless communications network of the first wireless device and a plurality of other wireless devices, having a shared transmission medium for the exchange of communications traffic between the wireless devices in the network, by each device in the network transmitting and receiving beacon transmissions that maintain coordination between the plurality of wireless devices in the wireless communication network and provide information regarding resource allocations for the shared transmission medium;

(b) determining at the first wireless device a value for a first interference condition in the shared transmission medium of the wireless communications network between said first wireless device and a first one of said other wireless devices in the network and receiving a first schedule of planned transmissions by the first one of said other wireless devices, wherein the value of the first interference condition and the first schedule are at least partly based on the received beacon transmissions at the first wireless device;

(c) determining at the first wireless device a value for a second interference condition in the shared transmission medium of the wireless communications network between said first wireless device and a second one of said other wireless devices in the network and receiving a second schedule of planned transmissions by the second one of said other wireless devices, wherein the value of the second interference condition and the second schedule are at least partly based on the received beacon transmissions at the first wireless device; and

(d) scheduling with the first wireless device a planned transmission to said first one of said other wireless devices in the network, wherein said scheduling step employs a time-overlapping access technique for the planned transmission when the second value for the second interference condition is less than a predetermined threshold, even though the second schedule of planned transmissions by the second one of said other wireless devices overlaps said planned transmission scheduling of the first wireless device with the first one of said other wireless devices.