LISTEN BEFORE TALK FOR CELLULAR IN UNLICENSED BAND

• US 20150382374A1
• Filed: 03/26/2015
• Published: 12/31/2015
• Est. Priority Date: 06/30/2014
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel IP Corporation (Intel Corporation)
• Inventors: Bhorkar, Abhijeet, Zong, Pingping, Papathanassiou, Apostolos, Ibars Casas, Christian
• Granted Patent: US 9,392,614 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 28/26 Resource reservation
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 72/1263 Mapping of traffic onto schedule, e.g. scheduled allocation or multiplexing of flows
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 72/30 Resource management for broadcast services
• CPC Class Codes: H04W 72/542 using measured or perceived quality
• CPC Class Codes: H04W 74/0808 using carrier sensing, e.g. carrier sense multiple access [CSMA]
• CPC Class Codes: H04W 88/08 Access point devices
• CPC Class Codes: H04W 88/10 adapted for operation in multiple networks, e.g. multi-mode access points

Abstract

Disclosed in some examples are systems, machine-readable media, methods, and cellular wireless devices which implement a Listen Before Talk (LBT) access scheme for a device operating according to a cellular wireless protocol in an unlicensed channel. A cellular wireless device may utilize the cellular wireless protocol in the unlicensed channel after the LBT access scheme has determined that a channel (a defined range of frequencies) in the unlicensed channel is idle for a particular period of time.

Claims

1. An eNodeB comprising:

a first transceiver to transmit and receive in an unlicensed channel using a first wireless protocol;

a second transceiver to transmit and receive in a licensed channel in accordance with a cellular wireless protocol;

a controller to;

determine, via the first transceiver, that an average energy of the unlicensed channel over a predetermined period of time is below a predetermined threshold, and in response;

send a wireless reservation message on the unlicensed channel via the first transceiver to reserve the unlicensed channel for a transmission of a Supplemental Downlink (SDL) Physical Downlink Shared Channel (PDSCH);

schedule at least one User Equipment (UE) serviced by the eNodeB to receive data on the SDL PDSCH in the unlicensed channel via a Physical Downlink Control Channel (PDCCH) on the licensed channel transmitted by the second transceiver; and

transmit the SDL PDSCH over the unlicensed channel at a cellular sub-frame boundary via the first transceiver.

2. The eNodeB of claim 1, wherein the cellular wireless protocol is a Long Term Evolution (LTE) or Long Term Evolution-Advanced (LTE-A) family of Standards defined by the Third Generation Partnership (3GPP).

3. The eNodeB of claim 2, wherein the first wireless protocol is a protocol according to an Institute for Electrical and Electronics Engineers (IEEE) 802.11 protocol.

4. The eNodeB of claim 1, wherein the wireless reservation message is one of:

a Clear to Send (CTS) message or a Request to Send (RTS) message.

5. The eNodeB of claim 1, wherein the controller is to implement a backoff process, and wherein the controller is to refrain from sending the reservation message, scheduling the UE and transmitting the SDL PDSCH until the backoff process is successful.

6. The eNodeB of claim 5, wherein the unlicensed channel is a channel in the Industrial, Scientific, and Medical (ISM) bands.

7. The eNodeB of claim 1, wherein the cellular sub-frame boundary is a start of an LTE or LTE-A sub-frame.

8. The eNodeB of claim 1, wherein the wireless reservation message includes a duration field that is set to a time that is at least the sum of a time needed to reach the beginning of the sub-frame boundary and the time needed to transmit the SDL PDSCH.

9. The eNodeB of claim 1, wherein the second transceiver is configured to provide a PDCCH in a licensed channel.

10. A non-transitory machine-readable medium that stores instructions, for execution by one or more processors of an eNodeB, which configure the eNodeB to perform operations to at least:

sense a first channel for a predetermined period of time, the first channel a wireless channel that is not exclusively licensed for cellular wireless communications;

determine that an average received power of the first channel indicates that the first channel is idle during the predetermined period of time; and

in response to the determination that the first channel is idle;

schedule at least one User Equipment (UE) serviced by the eNodeB to receive data on a Physical Downlink Shared Channel (PDSCH) transmitted on the first channel;

communicate the schedule to the UE via a control channel on a second channel, the second channel a wireless channel that is licensed for cellular wireless communications; and

transmit the PDSCH over the first channel via the first transceiver.

11. The non-transitory machine-readable medium of claim 10, wherein the instructions configure the eNodeB to at least send a reservation message on the first channel in response to the determination that the first channel is idle.

12. The non-transitory machine-readable medium of claim 11, wherein the reservation message is a message defined according to one of an Institute of Electrical and Electronics Engineers (IEEE) 802.11 family of standards.

13. The non-transitory machine-readable medium of claim 12, wherein the reservation message has a duration field that is at least as large as a sum of a time until the sub-frame boundary and a time needed to send the sub-frame.

14. The non-transitory machine-readable medium of claim 10, wherein the operations to transmit the PDSCH include operations to wait to transmit until a sub-frame boundary of the eNodeB.

15. The non-transitory machine-readable medium of claim 10, wherein the instructions further configure the eNodeB to implement a backoff procedure prior to scheduling the UE.

16. The non-transitory machine-readable medium of claim 10, wherein the eNodeB operates according to one of a Long Term Evolution (LTE) or Long Term Evolution-Advanced (LTE-A) wireless protocol.

17. A method comprising:

at an eNodeB;

determine, via a first transceiver, that an average energy of a first channel over a predetermined period of time is below a predetermined threshold, the first channel a wireless channel that is not exclusively licensed for cellular wireless, and in response;

select a random backoff period;

determine that the average energy of the first channel over the backoff period is below a second threshold;

schedule at least one User Equipment (UE) serviced by the eNodeB to receive data on a Supplemental Downlink (SDL) Physical Downlink Shared Channel (PDSCH) on the first channel;

communicate the schedule to the UE by transmission of a Physical Downlink Control Channel (PDCCH) on a second channel by a second transceiver, the second channel a wireless channel that is licensed for cellular wireless; and

transmit the SDL PDSCH over the unlicensed channel at a cellular sub-frame boundary via the first transceiver.

18. The method of claim 17 comprising providing a PDSCH on the second channel.

19. The method of claim 17, wherein the unlicensed channel is a frequency between 2.4 Ghz and 2.5 Ghz.

20. The method of claim 17, comprising sending a wireless reservation message on the first channel.

21. The method of claim 20, wherein the wireless reservation message is a broadcast message.

22. The method of claim 21, wherein the wireless reservation message is a Clear To Send (CTS) message.

23. The method of claim 21, wherein the wireless reservation message has a duration field that is set to a value that is at least the time until the sub-frame boundary plus the time necessary to transmit a PDSCH sub-frame.

24. The method of claim 21, wherein the predetermined threshold and the second threshold are the same value.

25. The method of claim 21, wherein the predetermined threshold and the second threshold are different values.