METHODS AND ARRANGEMENTS TO MITIGATE COLLISIONS IN WIRELESS NETWORKS

• US 20140192820A1
• Filed: 06/29/2013
• Published: 07/10/2014
• Est. Priority Date: 01/08/2013
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel IP Corporation (Intel Corporation)
• Inventors: Azizi, Shahrnaz, Stephens, Adrian P., Kenney, Thomas J., Perahia, Eldad, Park, Minyoung
• Granted Patent: US 10,200,974 B2
• Time in Patent Office: Days
• US Class Current: 370/445
• CPC Class Codes: C12N 15/74 Vectors or expression systems specially adapted for prokaryotic hosts other than E. coli, e.g. Lactobacillus, Micromonospora
• CPC Class Codes: H04W 72/04 Wireless resource allocation
• CPC Class Codes: H04W 74/0816 with collision avoidance
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

Logic for collision mitigation between transmissions of wireless transmitters and receivers operating at different bandwidths. Logic of the receivers may be capable of receiving and detecting signals transmitted at narrower bandwidths. In several embodiments, the receivers comprise a clear channel assessment logic that implements a guard interval (or cyclic prefix) detector to detect transmissions at narrower bandwidths. For instance, a two MegaHertz (MHz) bandwidth receiver may implement a guard interval detector to detect 1 MHz bandwidth signals and a 16M Hz bandwidth receiver may implement logic to detect one or more 1 MHz bandwidth signals and any other combination of, e.g., 1, 2, 4, 8 MHz bandwidth signals. In many embodiments, the guard interval detector may be implemented to detect guard intervals on a channel designated as a primary channel as well as on one or more non-primary channels.

Claims

1. A method to mitigate collisions between transmissions of devices operating at different bandwidths on a primary frequency of operation, the method comprising:

performing guard interval detection on a primary channel on the primary frequency in addition to start of the packet detection and energy detection on the primary channel and guard interval detection on a non-primary channel on the primary frequency to determine if a medium is busy in response to entering an active mode from a power-save mode;

determining whether the medium is busy based upon the performing; and

outputting an indication that the medium is busy to defer transmissions for a period of time in response to determining that the medium is busy.

2. The method of claim 1, further comprising outputting a clear channel assessment indicating that the medium is not busy in response to determining that the medium is not busy.

3. The method of claim 1, further comprising:

determining whether a station has transitioned from the power save mode to the active mode;

determining whether a network allocation vector is unexpired; and

following start of packet detection and energy detection and guard interval detection on a non-primary channel of the primary frequency rules if the station did not enter the active mode from the power-saving mode or if there is an indication that the network allocation vector is updated.

4. The method of claim 1, further comprising determining that a network allocation vector is not updated.

5. The method of claim 1, wherein performing the guard interval detection on the primary channel of the primary frequency comprises:

receiving, by a device, a signal on the primary frequency;

selecting the signal on the primary channel; and

correlating the signal on the primary channel to detect a guard interval in the signal on the primary channel.

6. The method of claim 5, wherein correlating comprises comparing peaks in the correlation to determine if one or more peaks are greater than a threshold correlation value.

7. The method of claim 5, wherein correlating comprises correlating the signal on the primary channel against a delayed version of the signal on the primary channel.

8. A device to mitigate collisions between transmissions of devices operating at different bandwidths on a primary frequency of operation, the device comprising:

a radio; and

clear channel assessment (CCA) logic coupled with the radio to perform guard interval detection on a primary channel of the primary frequency in addition to start of packet detection and energy detection on the primary channel and guard interval detection on a non-primary channel on the primary frequency to determine if a medium is busy in response to entering an active mode from a power-save mode;

determine whether the medium is busy based upon the performing; and

to output a clear channel assessment indicating that the medium is busy to defer transmissions for a period of time in response to determining that the medium is busy.

9. The device of claim 8, further comprising logic to select the signal on the primary channel.

10. The device of claim 8, wherein the CCA logic comprises logic to indicate a clear channel assessment if the medium is not busy.

11. The device of claim 8, wherein the CCA logic comprises logic to determine whether a station has transitioned from the power save mode to the active mode;

determine whether a network allocation vector is unexpired; and

follow start of the packet detection and energy detection and guard interval detection on a non-primary channel of the primary frequency rules if the station did not enter the active mode from the power-saving mode or if there is an indication that the network allocation vector is updated.

12. The device of claim 8, wherein the CCA logic comprises guard interval logic to receive a signal on the primary frequency;

select the signal on the primary channel; and

correlate the signal on the primary channel to detect a guard interval in the signal on the primary channel.

13. The device of claim 8, wherein the CCA logic comprises guard interval logic to compare peaks in the correlation to determine if one or more peaks are greater than a threshold correlation value.

14. The device of claim 8, wherein the CCA logic comprises guard interval logic to correlate the signal on the primary channel against a delayed version of the signal on the primary channel.

15. A system to mitigate collisions between transmissions of devices operating at different bandwidths on a primary frequency of operation, the device comprising:

a medium access control logic to generate a frame for transmission;

a receiver comprising clear channel assessment (CCA) logic to perform guard interval detection on a primary channel of the primary frequency in addition to start of packet detection and energy detection on the primary channel and guard interval detection on a non-primary channel of the primary frequency to determine if a medium is busy in response to entering an active mode from a power-save mode;

determine whether the medium is busy based upon the performing; and

output an indication that the medium is busy to defer transmissions for a period of time in response to detecting a guard interval on the primary channel; and

a transmitter to defer transmissions for a period of time in response to determining that the medium is busy.

16. The system of claim 15, further comprising an antenna coupled with the receiver to receive a signal.

17. The system of claim 15, wherein the CCA logic comprises logic to determine whether a station has transitioned from the power save mode to the active mode;

determine whether an network allocation vector is unexpired; and

follow start of the packet detection and energy detection and guard interval detection on a non-primary channel of the primary frequency rules if the station did not enter the active mode from the power-saving mode or if there is an indication that the network allocation vector is updated.

18. The system of claim 15, wherein the CCA logic comprises guard interval logic to receive a signal on the primary frequency;

select the signal on the primary channel; and

correlate the signal on the primary channel to detect a guard interval in the signal.

19. The system of claim 15, wherein the CCA logic comprises guard interval logic comprises logic to compare peaks in the correlation to determine if one or more peaks are greater than a threshold correlation value.

20. A machine-accessible product comprising:

a medium containing instructions to mitigate collisions between transmissions of devices operating at different bandwidths on a primary frequency of operation, wherein the instructions, when executed, cause a receiver to perform operations, the operations comprising;

performing guard interval detection on a primary channel on the primary frequency in addition to start of the packet detection and energy detection on the primary channel and guard interval detection on a non-primary channel on the primary frequency to determine if a medium is busy in response to entering an active mode from a power-save mode;

determining whether the medium is busy based upon the performing; and

outputting a clear channel assessment to defer transmissions for a period of time in response to determining that the medium is busy.

21. The machine-accessible product of claim 20, wherein the operations further comprise indicating a clear channel assessment that the medium is not busy if the medium is not busy.

22. The machine-accessible product of claim 20, wherein the operations further comprise:

determining whether a station has transitioned from the power save mode to the active mode;

determining whether an network allocation vector is unexpired; and

following start of the packet detection and energy detection and guard interval detection on a non-primary channel of the primary frequency rules if the station did not enter the active mode from the power-saving mode or if there is an indication that the network allocation vector is updated.

23. The machine-accessible product of claim 20, wherein performing the guard interval detection on the primary channel of the primary frequency comprises:

receiving, by a device, a signal on the primary frequency;

selecting the signal on the primary channel; and

correlating the primary channel to detect a guard interval in the signal.

24. The machine-accessible product of claim 23, wherein correlating comprises comparing peaks in the correlation to determine if one or more peaks are greater than a threshold correlation value.

25. The machine-accessible product of claim 23, wherein correlating comprises correlating the primary channel against a delayed version of the primary channel.