DSRC listen mode for Wi-Fi using DSRC spectrum

Patent metadata

Field	Value
Publication number	US-9503839-B2
Application number	US-201414286565-A
Country	US
Kind code	B2
Filing date	May 23, 2014
Priority date	May 31, 2013
Publication date	Nov 22, 2016
Grant date	Nov 22, 2016

Abstract

Methods, systems, and devices are described for detecting dedicated short range communications (DSRC) transmissions to determine whether to use at least a portion of the DSRC spectrum. In one embodiment, a multi-mode device may be operated outside of the DSRC spectrum using a first clock rate, and may then be switched to a second clock rate while operating outside of the DSRC spectrum to detect DSRC transmissions using the DSRC spectrum.

First claim

What is claimed is:

1. A method for detecting dedicated short range communications (DSRC) transmissions to determine whether to use at least a portion of the DSRC spectrum, comprising:
operating, by a multi-mode client device, outside of the DSRC spectrum using a first clock rate;
switching to a second clock rate while operating outside of the DSRC spectrum to detect DSRC transmissions using the DSRC spectrum;
determining an activity level in the DSRC spectrum;
operating a first communication channel in at least a portion of the DSRC spectrum based at least in part on the activity level; and
maintaining a second communication channel outside of the DSRC spectrum in conjunction with the first communication channel.

2. The method of claim 1 , further comprising:
determining whether the activity level exceeds a threshold.

3. The method of claim 2 , further comprising:
upon determining that the activity level fails to exceed the threshold, switching to the first clock rate for
operating in at least the portion of the DSRC spectrum.

4. The method of claim 2 , further comprising:
upon determining that the activity level exceeds the threshold, switching to the first clock rate for continuing to operate outside of the DSRC spectrum for a predetermined period of time.

5. The method of claim 1 , further comprising:
operating at the second clock rate for a predetermined period of time; and
upon an expiration of the predetermined period of time, switching to the first clock rate.

6. The method of claim 1 , further comprising:
reporting an occurrence of one or more detected DSRC transmissions to an access point (AP); and
receiving instructions from the AP, the instructions based at least in part on the reported occurrences of the DSRC transmissions; and
wherein operating the first communication channel in at least a portion of the DSRC spectrum is based at least in part on the instructions received from the AP.

7. The method of claim 1 , further comprising:
monitoring at least one of a plurality of frequency bands within the DSRC spectrum while operating at the second clock rate.

8. The method of claim 7 , wherein determining the activity level comprises:
determining the activity level of transmissions on each of the monitored frequency bands.

9. The method of claim 8 , further comprising:
switching to the first clock rate;
selecting at least one of the monitored frequency bands; and
operating the first communication channel in at least a portion of the DSRC spectrum using the at least one selected frequency band, the frequency band being selected based at least in part on the activity level.

10. The method of claim 9 , wherein selecting at least one of the monitored frequency bands comprises:
avoiding the selection of frequency bands allocated for safety-related transmissions in the DSRC spectrum.

11. The method of claim 1 , wherein the second clock rate is half the first clock rate.

12. A multi-mode client device for detecting dedicated short range communications (DSRC) transmissions to determine whether to use at least a portion of the DSRC spectrum, comprising:
a processor;
memory in electronic communication with the processor; and
instructions stored in the memory, the instructions being executable by the processor to:
operate the multi-mode device outside of the DSRC spectrum using a first clock rate;
switch to a second clock rate while operating outside of the DSRC spectrum to detect DSRC transmissions using the DSRC spectrum;
determine an activity level in the DSRC spectrum;
operate a first communication channel in at least a portion of the DSRC spectrum based at least in part on the activity level; and
maintain a second communication channel outside of the DSRC spectrum in conjunction with the first communication channel.

13. The multi-mode device of claim 12 , wherein the instructions are executable by the processor to:
determine whether the activity level exceeds a threshold.

14. The multi-mode device of claim 13 , wherein the instructions are executable by the processor to:
upon determining that the activity level fails to exceed the threshold, switch to the first clock rate for operating in at least the portion of the DSRC spectrum.

15. The multi-mode device of claim 13 , wherein the instructions are executable by the processor to:
upon determining that the activity level exceeds the threshold, switch to the first clock rate for continuing to operate outside of the DSRC spectrum for a predetermined period of time.

16. The multi-mode device of claim 12 , wherein the instructions are executable by the processor to:
operate at the second clock rate for a predetermined period of time; and
upon an expiration of the predetermined period of time, switch to the first clock rate.

17. The multi-mode device of claim 12 , wherein the instructions are executable by the processor to:
report an occurrence of one or more detected DSRC transmissions to an access point (AP); and
receive instructions from the AP, the instructions based at least in part on the reported occurrences of the DSRC transmissions; and
wherein operating the first communication channel in at least a portion of the DSRC spectrum is based at least in part on the instructions received from the AP.

18. The multi-mode device of claim 12 , wherein the instructions are executable by the processor to:
monitor at least one of a plurality of frequency bands within the DSRC spectrum while operating at the second clock rate.

19. The multi-mode device of claim 18 , wherein determining the activity level comprises:
determining the activity level of transmissions on each of the monitored frequency bands.

20. The multi-mode device of claim 19 , wherein the instructions are executable by the processor to:
switch to the first clock rate;
select at least one of the monitored frequency bands; and
operate the first communication channel in at least a portion of the DSRC spectrum using the at least one selected frequency band, the frequency band being selected based at least in part on the determined activity level.

21. The multi-mode device of claim 20 , wherein the instructions are executable by the processor to:
avoid the selection of frequency bands allocated for safety-related transmissions in the DSRC spectrum.

22. The multi-mode device of claim 12 , wherein the second clock rate is half the first clock rate.

23. A multi-mode client device for detecting dedicated short range communications (DSRC) transmissions to determine whether to use at least a portion of the DSRC spectrum, comprising:
means for operating the multi-mode device outside of the DSRC spectrum using a first clock rate;
means for switching to a second clock rate while operating outside of the DSRC spectrum to detect DSRC transmissions using the DSRC spectrum;
means for determining an activity level in the DSRC spectrum;
means for operating a first communication channel in at least a portion of the DSRC spectrum based at least in part on the activity level; and
means for maintaining a second communication channel outside of the DSRC spectrum in conjunction with the first communication channel.

24. The multi-mode device of claim 23 , further comprising:
means for determining whether activity level exceeds a threshold.

25. The multi-mode device of claim 24 , further comprising:
means for, upon determining that the activity l

Assignees

• Qualcomm Inc

Inventors

• Jose Jubin
• Wang Ying
• Shi Kai
• Wu Xinzhou
• Li Junyi

Classifications

• H04W72/00

  Local resource management · CPC title

• H04W88/06

  adapted for operation in multiple networks {or having at least two operational modes}, e.g. multi-mode terminals · CPC title

• H04W72/02

  Selection of wireless resources by user or terminal · CPC title

• H04W4/008 Primary

  Electricity · mapped topic

• H04W16/14

  Spectrum sharing arrangements {between different networks} · CPC title