LISTEN-BEFORE-TALK MECHANISM

• US 20170086152A1
• Filed: 09/17/2015
• Published: 03/23/2017
• Est. Priority Date: 09/17/2015
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Li, Chong, Zhang, Lei, Wu, Xinzhou, Li, Junyi
• Granted Patent: US 10,264,538 B2
• Time in Patent Office: Days
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 56/001 Synchronization between nodes
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• 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

Methods, systems, devices, and apparatuses are described for a listen-before-talk (LBT) mechanism. A wireless node, e.g., a base station, may determine that a channel is available based on completing a clear channel assessment (CCA) procedure. The wireless node may be associated with a first operator. The wireless node may transmit a first message on the channel in a subframe based on the CCA procedure. The first message may include a header portion that precedes a data portion. The first message may be time aligned with a second message transmitted from a second wireless node that is associated with the first operator.

Claims

1. A method for wireless communication, comprising:

determining, at a first wireless node, that a channel is available based at least in part on a clear channel assessment (CCA) procedure performed on the channel, the first wireless node associated with a first operator; and

transmitting a first message on the channel during a subframe based at least in part on the determining, the first message time aligned in the subframe with a second message transmitted from a second wireless node associated with the first operator, the first message and the second message comprising a header portion that precedes a data portion.

2. The method of claim 1, wherein the first message is unsynchronized with a third message transmitted by a third wireless node associated with a second operator that is different from the first operator.

3. The method of claim 1, further comprising:

exchanging radio frame configuration information with the second wireless node via a wireless wide area network (WWAN) communication channel, the radio frame configuration information comprising a timing synchronization field used to time align the first message and the second message.

4. The method of claim 3, wherein the radio frame configuration information further comprises a CCA configuration field, the CCA configuration field synchronizing the CCA procedure at the first wireless node with a CCA procedure at the second wireless node.

5. The method of claim 1, further comprising:

modulating the first message transmitted during the subframe according to a modulation scheme.

6. The method of claim 1, wherein the header portion of the first message comprises the same information as the header portion of the second message.

7. The method of claim 1, wherein the data portion of the first message comprises different information from the data portion of the second message.

8. The method of claim 1, wherein the channel comprises multiple sub-bands and the first message and the second message are synchronized across each sub-band of the multiple sub-bands.

9. The method of claim 1, wherein the header portions of the first message and the second message comprise a Wi-Fi preamble, the Wi-Fi preamble comprising Wi-Fi specific information and wireless wide area network (WWAN) specific information.

10. The method of claim 9, wherein the Wi-Fi specific information is decodable by the first wireless node, the second wireless node, and a Wi-Fi configured wireless node.

11. The method of claim 9, wherein the WWAN specific information is undecodable by a Wi-Fi configured wireless node.

12. The method of claim 1, further comprising:

transmitting additional messages via the channel during a plurality of subframes following the CCA procedure, each additional message comprising the header portion and the data portion in the subframe, wherein the header portion is the same in each subframe.

13. The method of claim 1, further comprising:

performing a request-to-send/clear-to-send (RTS/CTS) procedure on the channel prior to transmitting the first message.

14. The method of claim 1, further comprising:

including a clear-to-send-to-self (CTS-S) field in the header portion of the first message.

15. The method of claim 1, further comprising:

transmitting a pilot tone on an unlicensed radio frequency spectrum band using a Wi-Fi configured protocol; and

receiving, via a wireless wide area network (WWAN), a channel condition report from a wireless node associated with the first operator.

16. The method of claim 15, wherein the pilot tone is transmitted subsequent to the header portion of the first message and precedes the data portion of the first message.

17. The method of claim 1, further comprising:

detecting an interfering message transmitted from a third wireless node during the CCA procedure;

determining that the third wireless node is associated with the first operator; and

transmitting the first message based at least in part on determining that the third wireless node is associated with the first operator.

18. The method of claim 17, wherein determining that the third wireless node is associated with the first operator comprises:

decoding a header portion of the interfering message.

19. The method of claim 18, further comprising:

identifying a failure of the decoding of the header portion of the interfering message; and

refraining from transmitting the first message during the subframe based at least in part on the identified failure, the refraining further based at least in part on an energy level associated with the interfering message being below a threshold level.

20. The method of claim 1, further comprising:

detecting an interfering message transmitted from a third wireless node during the CCA procedure;

determining that the third wireless node is unassociated with the first operator; and

refraining from transmitting the first message based at least in part on determining that the third wireless node is unassociated with the first operator.

21. The method of claim 1, wherein the channel is associated with synchronized long term evolution controlled Wi-Fi (LTE-CW) communications.

22. The method of claim 1, wherein the header portions of the first message and the second message comprise an operator identifier field associated with a public land mobile network (PLMN) operator.

23. An apparatus for wireless communication, comprising:

a processor;

memory in electronic communication with the processor; and

instructions stored in the memory, the instructions being executable by the processor to;

determine, at a first wireless node, that a channel is available based at least in part on a clear channel assessment (CCA) procedure performed on the channel, the first wireless node associated with a first operator; and

transmit a first message on the channel during a subframe based at least in part on the determining, the first message time aligned in the subframe with a second message transmitted from a second wireless node associated with the first operator, the first message and the second message comprising a header portion that precedes a data portion.

24. The apparatus of claim 23, wherein the first message is unsynchronized with a third message transmitted by a third wireless node associated with a second operator that is different from the first operator.

25. The apparatus of claim 23, further comprising instructions executable by the processor to:

exchange radio frame configuration information with the second wireless node via a wireless wide area network (WWAN) communication channel, the radio frame configuration information comprising a timing synchronization field used to time align the first message and the second message.

26. The apparatus of claim 25, wherein the radio frame configuration information further comprises a CCA configuration field, the CCA configuration field synchronizing the CCA procedure at the first wireless node with a CCA procedure at the second wireless node.

27. The apparatus of claim 23, further comprising instructions executable by the processor to:

modulate the first message transmitted during the subframe according to a modulation scheme.

28. The apparatus of claim 23, wherein the header portion of the first message comprises the same information as the header portion of the second message.

29. An apparatus for wireless communication, comprising:

means for determining, at a first wireless node, that a channel is available based at least in part on a clear channel assessment (CCA) procedure performed on the channel, the first wireless node associated with a first operator; and

means for transmitting a first message on the channel during a subframe based at least in part on the determining, the first message time aligned in the subframe with a second message transmitted from a second wireless node associated with the first operator, the first message and the second message comprising a header portion that precedes a data portion.

30. A non-transitory computer-readable medium storing computer-executable code for wireless communication, the code executable by a processor to:

determine, at a first wireless node, that a channel is available based at least in part on a clear channel assessment (CCA) procedure performed on the channel, the first wireless node associated with a first operator; and

transmit a first message on the channel during a subframe based at least in part on the determining, the first message time aligned in the subframe with a second message transmitted from a second wireless node associated with the first operator, the first message and the second message comprising a header portion that precedes a data portion.