Techniques for performing carrier sense adaptive transmission in unlicensed spectrum

• US 10,110,337 B2
• Filed: 07/27/2016
• Issued: 10/23/2018
• Est. Priority Date: 08/28/2015
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Naghshvar, Mohammad, Sadek, Ahmed Kamel, Valliappan, Nachiappan
• Primary Examiner(s): Crutchfield, Christopher
• Assistant Examiner(s): Lindenbaum, Alan
• Application Number:
  US15/221,294
• Publication Number:
  US 20170063484A1
• Time in Patent Office: 818 Days
• Field of Search: None
• CPC Class Codes: H04B 17/318 Received signal strength
• CPC Class Codes: H04B 17/336 Signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR]
• CPC Class Codes: H04J 11/0023 Interference mitigation or co-ordination direct sequence spread spectrum [DSSS] systems H04B1/7097; frequency hopping H04B1/713; allocation criteria for ingress interference avoidance H04L5/0062; frequency allocation criteria for requirements on out-of-channel emissions H04L5/0066; arrangements for removing intersymbol interference or baseband equalisers H04L25/03006; peak power aspects in multicarrier modulation H04L27/2614; power management H04W52/00; traffic scheduling H04W72/54, H04W72/541
• CPC Class Codes: H04L 47/29 using a combination of thresholds
• CPC Class Codes: H04L 5/0055 Physical resource allocation for ACK/NACK for physical mapping arrangements in ARQ protocols H04L1/1861
• CPC Class Codes: H04L 69/22 Parsing or analysis of headers
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 16/32 Hierarchical cell structures
• CPC Class Codes: H04W 28/14 using intermediate storage
• CPC Class Codes: H04W 40/244 using a network of reference devices, e.g. beaconing
• CPC Class Codes: H04W 74/0808 using carrier sensing, e.g. carrier sense multiple access [CSMA]
• CPC Class Codes: H04W 74/0816 with collision avoidance
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

Aspects for reducing interference between networks are provided. A signal transmitted by one or more devices in a first network over a communications medium using an unlicensed frequency spectrum is decoded to determine one or more parameters of a packet in the signal. A level of utilization of the communications medium by the one or more devices in the first network can be estimated based at least in part on a signal strength of the signal and the one or more parameters. A period of time for communicating in a second network over the communications medium using the unlicensed frequency spectrum can be adjusted based at least in part on the level of utilization of the communications medium by the first network. In addition, a number of active transmitters over the communications medium can be determined based at least in part on identifying a source entity related to transmission of the signal, and adjusting the time for communicating in the second network can be further based at least in part on the number of active transmitters.

Claims

1. A method for reducing interference between networks, comprising:

decoding a signal transmitted by one or more devices in a first network over a communications medium using an unlicensed frequency spectrum to determine one or more parameters in a header of a packet in the signal;

determining, based at least in part on the one or more parameters, that the packet is an acknowledgement packet of a previous communication from the first network;

computing, based on determining that the packet is an acknowledgement packet of the previous communication, an estimated level of utilization of the communications medium by the one or more devices in the first network based at least in part on all of a signal strength of the signal and the one or more parameters and a second signal strength of the previous communication; and

adjusting a period of time for communicating in a second network over the communications medium using the unlicensed frequency spectrum based at least in part on the estimated level of utilization of the communications medium.

2. The method of claim 1, further comprising determining a number of active transmitters over the communications medium based at least in part on identifying a source entity related to transmission of the signal and the previous communication.

3. The method of claim 2, wherein determining the number of active transmitters is based at least in part on classifying the signal and the previous communication based on an identification of the source entity in the signal.

4. The method of claim 3, further comprising computing a second estimated level of utilization of the communications medium by the source entity based at least in part on determining a duration of the signal and/or one or more other signals classified as transmitted by the source entity over a period of time.

5. The method of claim 4, wherein determining the number of active transmitters is based at least in part on the second estimated level of utilization of the communications medium computed for the source entity and other estimated levels of utilization of the communications medium computed for other source entities.

6. The method of claim 2, further comprising setting at least one of a minimum time for communicating in the second network over the communications medium, a maximum time for communicating in the second network over the communications medium, or any combination thereof, based at least in part on the number of active transmitters, wherein adjusting the time for communicating in the second network is based on at least one of the minimum time, the maximum time, or any combination thereof.

7. The method of claim 6, wherein setting the at least one of the minimum time and the maximum time is further based at least in part on determining a number of access points in the second network having signal strengths that achieve one or more thresholds.

8. The method of claim 2, wherein adjusting the time for communicating in the second network is further based at least in part on the number of active transmitters.

9. The method of claim 2, wherein determining the number of active transmitters comprises determining whether the signal from the source entity and/or other signals from other source entities achieve a threshold signal strength.

10. The method of claim 2, wherein determining the number of active transmitters comprises determining whether the signal from the source entity and/or other signals from other source entities are over a primary or secondary channel and/or include beacon signals that achieve one or more threshold signal strengths.

11. The method of claim 1, wherein the one or more parameters include one or more of a duration of the signal, a modulation and coding scheme (MCS) of the signal, or a type of the packet.

12. The method of claim 11, further comprising:

determining a signal-to-noise ratio (SNR) based at least in part on the MCS of the signal, wherein the signal strength is determined based on the SNR;

determining a signal-to-interference ratio (SIR) based at least in part on the signal strength, a transmit power for communicating in the second network, and a determined pathloss based on another signal strength of an acknowledgement packet related to the signal; and

determining to utilize the duration of the signal in computing the estimated level of utilization of the communications medium based at least in part on comparing a ratio of the SNR to the SIR to a threshold.

13. The method of claim 11, further comprising:

determining a signal-to-noise ratio (SNR) based at least in part on the MCS of the signal, wherein the signal strength is determined based on the SNR;

determining a signal-to-interference-and-noise ratio (SINR) based at least in part on the signal strength, a determined noise power related to the signal, a transmit power for communicating in the second network, and a determined pathloss based on another signal strength of an acknowledgement packet related to the signal; and

determining to utilize the duration of the signal in computing the estimated level of utilization of the communications medium based at least in part on comparing a ratio of the SNR to the SINR to a threshold.

14. The method of claim 11, further comprising determining to utilize the duration of the signal in computing the estimated level of utilization of the communications medium based at least in part on determining that the packet is the acknowledgement packet of the previous communication and on comparing the signal strength to a threshold, wherein determining that the packet is the acknowledgement packet of the previous communication comprises determining that a receive address in the header of the packet matches a transmit address in a second header of the previous communication.

15. The method of claim 11, further comprising:

determining a signal-to-noise ratio (SNR) based at least in part on the MCS of the signal, wherein the signal strength is based on the SNR; and

determining a signal-to-interference ratio (SIR) based at least in part on the signal strength, a transmit power for communicating in the second network, and a determined pathloss based on another signal strength of an acknowledgement packet related to the signal; and

applying a weight to the duration of the signal in computing the estimated level of utilization of the communications medium based at least in part on comparing a ratio of the SNR to the SIR to one or more thresholds.

16. The method of claim 11, further comprising:

determining a signal-to-noise ratio (SNR) based at least in part on the MCS of the signal, wherein the signal strength is determined based on the SNR;

determining a signal-to-interference-and-noise ratio (SINR) based at least in part on the signal strength, a determined noise power related to the signal, a transmit power for communicating in the second network, and a determined pathloss based on another signal strength of an acknowledgement packet related to the signal; and

applying a weight to the duration of the signal in computing the estimated level of utilization of the communications medium based at least in part on comparing a ratio of the SNR to the SINR to one or more thresholds.

17. The method of claim 11, further comprising applying a weight to the duration of the signal in computing the estimated level of utilization of the communications medium based at least in part on determining that the packet is the acknowledgement packet of the previous communication and on comparing the signal strength to one or more thresholds.

18. The method of claim 1, wherein decoding the signal is based at least in part on determining the signal strength of the signal is at least at a threshold level.

19. The method of claim 1, wherein communications by the second network are based on Carrier Sense Adaptive Transmission (CSAT), the method further comprising receiving the signal during a period in which transmission by the second network is OFF (T_OFF) in a CSAT cycle of a CSAT ON period.

20. The method of claim 1, wherein the first network is a Wi-Fi network and the second network is a Long Term Evolution (LTE) network.

21. The method of claim 1, wherein adjusting the time for communicating in the second network over the communications medium includes skipping the time in one or more cycles based at least in part on determining that adjusting the time results in the time being less than a threshold.

22. An apparatus for reducing interference between networks, comprising:

a transceiver;

a memory configured to store a buffer including one or more messages for transmitting via the transceiver; and

at least one processor communicatively coupled with the transceiver and the memory, wherein the at least one processor is configured to;

decode a signal transmitted by one or more devices in a first network over a communications medium using an unlicensed frequency spectrum to determine one or more parameters in a header of a packet in the signal;

determine, based at least in part on the one or more parameters, that the packet is an acknowledgement packet of a previous communication from the first network;

compute, based on determining that the packet is an acknowledgement packet of the previous communication, an estimated level of utilization of the communications medium by the one or more devices in the first network based at least in part on all of a signal strength of the signal and the one or more parameters and a second signal strength of the previous communication; and

adjust a period of time for communicating in a second network over the communications medium using the unlicensed frequency spectrum based at least in part on the estimated level of utilization of the communications medium.

23. The apparatus of claim 22, wherein the one or more parameters include one or more of a duration of the signal, a modulation and coding scheme (MCS) of the signal, or a type of the packet.

24. The apparatus of claim 23, wherein the at least one processor is further configured to:

determine a signal-to-noise ratio (SNR) based at least in part on the MCS of the signal, wherein the signal strength is determined based on the SNR; and

determine a signal-to-interference ratio (SIR) based at least in part on the signal strength, a transmit power for communicating in the second network, and a determined pathloss based on another signal strength of an acknowledgement packet related to the signal; and

determine to utilize the duration of the signal in computing the estimated level of utilization of the communications medium based at least in part on comparing a ratio of the SNR to the SIR to a threshold.

25. The apparatus of claim 22, wherein the at least one processor is configured to decode the signal based at least in part on determining the signal strength of the signal is at least at a threshold level.

26. The apparatus of claim 22, further comprising at least one antenna coupled to the transceiver, wherein the antenna is used in receiving or transmitting one or more signals.

27. An apparatus for reducing interference between networks, comprising:

means for decoding a signal transmitted by one or more devices in a first network over a communications medium using an unlicensed frequency spectrum to determine one or more parameters in a header of a packet in the signal;

means for determining, based at least in part on the one or more parameters, that the packet is an acknowledgement packet of a previous communication from the first network;

means for computing, based on determining that the packet is an acknowledgement packet of the previous communication, an estimated level of utilization of the communications medium by the one or more devices in the first network based at least in part on all of a signal strength of the signal and the one or more parameters and a second signal strength of the previous communication; and

means for adjusting a period of time for communicating in a second network over the communications medium using the unlicensed frequency spectrum based at least in part on the estimated level of utilization of the communications medium.

28. The apparatus of claim 27, wherein the means for decoding decodes the signal based at least in part on determining the signal strength of the signal is at least at a threshold level.

29. A non-transitory computer-readable medium storing computer executable code for reducing interference between networks, the code comprising:

code for decoding a signal transmitted by one or more devices in a first network over a communications medium using an unlicensed frequency spectrum to determine one or more parameters in a header of a packet in the signal;

code for determining, based at least in part on the one or more parameters, that the packet is an acknowledgement packet of a previous communication from the first network;

code for computing, based on determining that the packet is an acknowledgement packet of the previous communication, an estimated level of utilization of the communications medium by the one or more devices in the first network based at least in part on all of a signal strength of the signal and the one or more parameters and a second signal strength of the previous communication; and

code for adjusting a period of time for communicating in a second network over the communications medium using the unlicensed frequency spectrum based at least in part on the estimated level of utilization of the communications medium.

30. The non-transitory computer-readable medium of claim 29, wherein the code for decoding decodes the signal based at least in part on determining the signal strength of the signal is at least at a threshold level.