License assisted listen-before-talk

Patent metadata

Field	Value
Publication number	US-2018332575-A1
Application number	US-201615533790-A
Country	US
Kind code	A1
Filing date	Oct 31, 2016
Priority date	Oct 31, 2016
Publication date	Nov 15, 2018
Grant date	—

Abstract

Systems and methods are disclosed herein that relate to the use of signals in a licensed spectrum to assist with determining a status of an unlicensed channel(s) in an unlicensed spectrum. In some embodiments, a method of operation of a wireless device in a wireless system in which the wireless device transmits and/or receives in both a licensed spectrum and an unlicensed spectrum comprises attempting to detect a busy indication transmitted in the licensed spectrum. The busy indication is an indication that another wireless device is transmitting in the unlicensed spectrum. The method further comprises determining whether to transmit in the unlicensed spectrum based on whether the wireless device has detected a busy indication transmitted in the licensed spectrum. By using signals in the licensed spectrum, the hidden node problem and/or the exposed node problem in the unlicensed spectrum can be mitigated.

First claim

1 . A method of operation of a wireless device in a wireless system in which the wireless device transmits and/or receives in both a licensed spectrum and an unlicensed spectrum, comprising:
attempting to detect a busy indication transmitted in the licensed spectrum, the busy indication being an indication that another wireless device is transmitting in the unlicensed spectrum; and determining whether to transmit in the unlicensed spectrum based on whether the wireless device has detected a busy indication transmitted in the licensed spectrum.

2 . The method of claim 1 further comprising, upon determining to transmit in the unlicensed spectrum, transmitting in the unlicensed spectrum.

3 . The method of claim 1 wherein attempting to detect a busy indication transmitted in the licensed spectrum comprises attempting to detect a busy indication transmitted in the licensed spectrum by a serving radio access node of the wireless device.

4 . The method of claim 1 wherein attempting to detect a busy indication transmitted in the licensed spectrum comprises attempting to detect a busy indication transmitted in the licensed spectrum by another wireless device.

5 . The method of claim 1 wherein attempting to detect a busy indication transmitted in the licensed spectrum comprises attempting to detect both a busy indication transmitted in the licensed spectrum by a serving radio access node of the wireless device and a busy indication transmitted in the licensed spectrum by another wireless device.

6 . The method of claim 1 further comprising:
performing a clear channel assessment for a channel in the unlicensed spectrum;
wherein determining whether to transmit in the unlicensed spectrum comprises determining to transmit in the unlicensed spectrum upon determining that the wireless device has not detected a busy indication transmitted in the licensed spectrum and determining that the channel in the unlicensed spectrum is clear as a result of performing the clear channel assessment for the channel in the unlicensed spectrum.

7 . The method of claim 1 wherein determining whether to transmit in the unlicensed spectrum based on whether the wireless device has detected a busy indication transmitted in the licensed spectrum comprises:
determining that the wireless device has detected a busy indication transmitted in the licensed spectrum;
determining that the detected busy indication is a busy indication transmitted in the licensed spectrum by another wireless device; and
determining whether the wireless device has also detected a busy indication transmitted in the licensed spectrum by a serving radio access node of the wireless device;
wherein the wireless device determines to transmit in the unlicensed spectrum upon determining that the wireless device has not also detected a busy indication transmitted in the licensed spectrum by the serving radio access node of the wireless device.

8 . The method of claim 1 wherein determining whether to transmit in the unlicensed spectrum based on whether the wireless device has detected a busy indication transmitted in the licensed spectrum comprises:
determining that the wireless device has detected a busy indication transmitted in the licensed spectrum;
determining that the detected busy indication is a busy indication transmitted in the licensed spectrum by another wireless device;
decoding the busy indication to obtain an identifier of an intended recipient of the transmission in the unlicensed spectrum by the other wireless device; and
determining whether the intended recipient is a serving radio access node of the wireless device;
wherein the wireless device determines to transmit in the unlicensed spectrum upon determining that the intended recipient is not the serving radio access node of the wireless device.

9 . The method of claim 1 further comprising, upon determining to transmit in the unlicensed spectrum, transmitting a busy indication in the licensed spectrum to the serving radio access node of the wireless device.

10 . The method of claim 9 wherein transmitting the busy indication comprises transmitting the busy indication using a scheduled resource in the licensed spectrum.

11 . The method of claim 9 wherein transmitting the busy indication comprises transmitting the busy indication using a preconfigured channel in the licensed spectrum.

12 . The method of claim 9 wherein transmitting the busy indication comprises transmitting the busy indication in an uplink channel in an uplink spectrum of a cellular communications network, the cellular communications network comprising the serving radio access node.

13 . The method of claim 9 wherein transmitting the busy indication comprises transmitting the busy indication using resources designated for device-to-device traffic.

14 . The method of claim 9 wherein the transmitted busy indication is a message comprising an indication of a resource in the unlicensed spectrum on which the wireless device is transmitting.

15 . The method of claim 9 wherein the unlicensed spectrum is logically divided into a plurality of channels, and the transmitted busy indication is a message comprising an indication of one or more channels in the unlicensed spectrum in which the wireless device is transmitting.

16 . The method of claim 9 wherein the transmitted busy indication is a message comprising an indication of an intended recipient of the transmission by the wireless device in the unlicensed spectrum.

17 - 18 . (canceled)

19 . A wireless device for a wireless system in which the wireless device transmits and/or receives in both a licensed spectrum and an unlicensed spectrum, comprising:
a transceiver; at least one processor; and memory comprising instructions executable by the at least one processor whereby the wireless device is operable to:
attempt to detect a busy indication transmitted in the licensed spectrum, the busy indication being an indication that another wireless device is transmitting in the unlicensed spectrum;
determine whether to transmit in the unlicensed spectrum based on whether the wireless device has detected a busy indication transmitted in the licensed spectrum; and
upon determining to transmit in the unlicensed spectrum, transmit in the unlicensed spectrum.

20 . (canceled)

21 . A method of operation of a radio access node in a wireless system, comprising:
receiving a first busy indication in a licensed spectrum from a wireless device, the first busy indication being an indication that the wireless device is transmitting in an unlicensed spectrum; and transmitting a second busy indication in a licensed spectrum indication in response to receiving the first busy indication, the second busy indication being an indication that the wireless device is transmitting in the unlicensed spectrum.

22 . The method of claim 21 wherein the second busy indication comprises at least one of a group consisting of: a parameter that is indicative of a validity of the second busy indication, an indication of an angle of arrival of the first busy indication at the radio network node, and an indication of one or more channels in the unlicensed spectrum in which the wireless device is transmitting.

23 . The method of claim 21 wherein the first busy indication comprises at least one of a group consisting of: an indication of a resource in the unlicensed spectrum on which the wireless device is transmitting, an indication of one or more channels in the

Assignees

• Ericsson Telefon Ab L M

Inventors

• Fodor Gabor
• Lincoln Bo
• Björkegren Häkan
• Kronander Jonas
• Wallén Anders
• Gunnarsson Fredrik

Classifications

• H04W72/21 Primary

  in the uplink direction of a wireless link, i.e. towards the network · CPC title

• H04W74/004

  in the uplink, i.e. towards network · CPC title

• H04W74/0816

  with collision avoidance · CPC title

• H04W74/02

  Hybrid access · CPC title

• H04W72/0413 Primary

  Electricity · mapped topic