Techniques for managing handovers in an unlicensed radio frequency spectrum band

Patent metadata

Field	Value
Publication number	US-10212636-B2
Application number	US-201514956686-A
Country	US
Kind code	B2
Filing date	Dec 2, 2015
Priority date	Dec 12, 2014
Publication date	Feb 19, 2019
Grant date	Feb 19, 2019

Abstract

Techniques for managing handovers in an unlicensed radio frequency spectrum band may provide that a serving base station may receive one or more base station measurement reports and one or more UE measurement reports. The base station measurement reports may include information associated with one or more devices that may transmit signals using an unlicensed radio frequency spectrum band. The UE measurement reports may include information associated with one or more devices that may generate interfering signals at the UE, which may include interfering signals from one or more devices that are not detected by the serving base station. The serving base station may, in some examples, determine whether to handover the UE to a second base station based at least in part on the base station measurement report and the UE measurement report.

First claim

What is claimed is:

1. A method of wireless communications comprising:
receiving, at a first base station, a plurality of base station measurement reports, each of the plurality of base station measurement reports received from one of a plurality of base stations, the plurality of base station measurement reports including information associated with one or more first devices that transmits first signals using an unlicensed radio frequency spectrum band, and the one or more first devices different from the plurality of base stations;
receiving, at the first base station, a user equipment (UE) measurement report from a UE, the UE measurement report including information associated with one or more second devices that transmits second signals using the unlicensed radio frequency spectrum band, and the one or more second devices different from the UE;
determining, at the first base station, that the one or more first devices or the one or more second devices are outside of an energy detection range of the first base station based at least in part on the plurality of base station measurement reports and the UE measurement report;
determining, at the first base station, to handover the UE based at least in part on the determination that the one or more first devices or the one or more second devices are outside of the energy detection range of the first base station;
selecting, at the first base station, a target base station from among the plurality of base stations, wherein the selecting is based at least in part on the one or more first devices or the one or more second devices that are outside the energy detection range of the first base station being within a second energy detection range of the target base station; and
transmitting, from the first base station, a handover command based at least in part on the determination to handover the UE to the target base station.

2. The method of claim 1 , wherein the one or more first devices comprise one or more of a non-serving base station or a non-serving wireless local area network (WLAN) access point (AP).

3. The method of claim 1 , wherein the one or more second devices comprise one or more of a non-serving base station or a non-serving wireless local area network (WLAN) access point (AP).

4. The method of claim 1 , wherein the one or more first devices are within an energy detection range of the one base station of the plurality of base stations that provided a base station measurement report of the plurality of base station measurement reports.

5. The method of claim 1 , wherein the one or more second devices are within an energy detection range of the UE.

6. The method of claim 1 , further comprising:
receiving signals at time intervals that are different from time intervals of transmissions of at least one of the one or more first devices or the one or more second devices.

7. The method of claim 1 , wherein the determining to handover the UE comprises:
determining that at least one of the one or more first devices or the one or more second devices is causing interference at the UE with signals transmitted from the first base station on the unlicensed radio frequency spectrum band; and
the method further comprising determining that the target base station can transmit signals to the UE with reduced interference relative to the first base station.

8. The method of claim 7 , wherein the determining to handover the UE further comprises one or more of:
determining that a signal strength of transmissions of the target base station at the UE exceeds a threshold value;
determining that the target base station is within an energy detection range of the at least one of the one or more first devices or the one or more second devices that is causing the interference at the UE;
or determining that the target base station is within an energy detection range of the first base station.

9. The method of claim 7 , wherein a signal strength of the first base station at the UE exceeds a signal strength of the target base station at the UE.

10. The method of claim 1 , wherein the transmitting the handover command comprises: transmitting the handover command to the UE to initiate communications between the UE and the target base station.

11. The method of claim 1 , wherein the plurality of base station measurement reports comprise an identification and an energy measurement of at least one of a non-serving base station or a non-serving wireless local area network (WLAN) access point (AP).

12. The method of claim 11 , wherein the plurality of base station measurement reports further comprise preamble detection information for at least one of the non-serving base station or the non-serving WLAN AP.

13. The method of claim 11 , wherein the plurality of base station measurement reports are received via a backhaul link.

14. The method of claim 1 , wherein the UE measurement report comprises an energy measurement associated with one or more of the second signals received at the UE from at least one of the one or more second devices.

15. The method of claim 14 , wherein the UE measurement report comprises a plurality of measurements taken on a plurality of frequencies of the unlicensed radio frequency spectrum band that are different from a frequency of the first base station.

16. The method of claim 14 , wherein the UE measurement report comprises a plurality of measurements taken at time intervals having a duration selected to allow the UE to perform measurements of at a least one of a beacon signal for wireless local area network (WLAN) access point (AP) transmissions or a demodulation reference signal (DRS) signal for other base station transmissions.

17. The method of claim 1 , wherein the determining to handover the UE is based at least in part on a loading metric associated with the target base station.

18. The method of claim 17 , wherein the loading metric comprises channel occupancy information associated with the target base station.

19. The method of claim 1 , wherein the target base station is selected based at least in part on the target base station being in an energy detection range or preamble detect range of an interfering non-serving base station or an interfering non-serving wireless local area network (WLAN) access point (AP).

20. An apparatus for wireless communications at a wireless device, comprising:
a processor;
memory in electronic communication with the processor; and
the processor and memory configured to:
receive, at a first base station, a plurality of base station measurement reports, each of the plurality of base station measurement reports received from one of a plurality of base stations, the plurality of base station measurement reports including information associated with one or more first devices that transmits first signals using an unlicensed radio frequency spectrum band, and the one or more first devices different from the plurality of base stations;
receive, at the first base station, a user equipment (UE) measurement report from a UE, the UE measurement report including information associated with one or more second devices that transmits second signals on the unlicensed radio frequency spectrum band, and the one or more second devices different from the UE;
determine, at the first base station, that the one or more first devices or the one or more second devices are outside of an energy detection range of the first base station based at least in part on the plurality of base station measurement reports and the UE measurement report;
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Assignees

• Qualcomm Inc

Inventors

• Damnjanovic Aleksandar
• Vajapeyam Madhavan Srinivasan
• Patwardhan Ravindra Manohar

Classifications

• H04W16/14

  Spectrum sharing arrangements {between different networks} · CPC title

• H04W24/10 Primary

  Scheduling measurement reports {; Arrangements for measurement reports} · CPC title

• H04W36/30

  by measured or perceived connection quality data · CPC title

• H04W36/24 Primary

  Reselection being triggered by specific parameters · CPC title

• H04W36/302

  due to low signal strength · CPC title