Beam management methods and apparatus

1. A method of operating a first communications device, the method comprising;

receiving, from a second communications device, signal quality information for a first period of time corresponding to beams transmitted by the first communications device;

identifying a set of X broad beams having the best reported quality, said set of X beams including one or more broad beams;

identifying a set of Y narrow beams having the best reported quality, said set of Y beams including one or more narrow beams;

determining a first quality variance for the best Y beam for the first period of time; and

determining a preferred beam mode based on at least the first quality variance, said preferred beam mode being one of a broad beam mode or a narrow beam mode, wherein determining the preferred beam mode includes:

determining if the first quality variance is greater than a first threshold; and

when it is determined that the first quality variance is greater than the first threshold said step determining a preferred beam mode is further based on: i) a first quality indicator value for the best beam in said set of Y narrow beams, said first quality indicator value generated from multiple reported signal quality values, corresponding to the best Y beam, included in said received signal quality information; and ii) a second quality indicator value for the best beam in said set of X broad beams, said second quality indicator value generated from multiple reported signal quality values, corresponding to the best X beam, included in said received signal quality information.

2. The method of claim 1 , further comprising:

setting the preferred beam mode to narrow beam mode when it is determined that the first quality variance is not greater than the first threshold.

3. The method of claim 2 , where said first quality variance is for a time period of 5 milliseconds or less.

4. The method of claim 1 , further comprising, when it is determined that the first quality variance is greater than the first threshold:

determining a difference between the first quality indicator value and the second quality indicator value;

determining if the difference is below a second threshold; and

setting the preferred beam mode to narrow beam mode when it is determined that the difference is not below the second threshold.

5. The method of claim 4 , further comprising:

when said difference is below the second threshold, determining if the quality variance of the best beam in the set of X broad beams is below a third threshold; and

in response to determining that the quality variance of the best beam in the set of X broad beams is below the third threshold setting the preferred beam mode to broad beam mode; and

otherwise setting the preferred beam mode to narrow beam mode.

6. The method of claim 2 , further comprising, prior to transmitting, using the beam corresponding to the preferred beam mode, data to the second communications device, making a decision whether or not to modify the preferred beam mode, the method comprising:

determining if there is a broad beam covering an area in which the second communications device is located and a third communications device is located, said broad beam covering said area being a candidate beam;

if it is determined that there is no broad beam covering an area in which the second communications device is located and a third communications device is located leaving the preferred beam mode and beam unchanged; and

if it is determined that there is a broad beam covering an area in which the second communications device is located and a third communications device is located, the method further comprising:

making a decision as to whether to set the beam mode to broad beam mode and the preferred beam to the candidate beam based on one or more of: i) traffic requirements for traffic to be transmitted to at least one of the second and third communications devices; ii) the amount of data to be transmitted to the third communications device and iii) the amount of data to be transmitted to the second communications device.

7. The method of claim 6 , wherein making the decision as to whether to set the beam mode to broad beam mode and the preferred beam to the candidate beam includes:

deciding to set the beam mode to broad beam mode and the preferred beam to the candidate beam based on one or more of: traffic requirements for traffic to be transmitted to at least one of the second and third communications devices; ii) the amount of data to be transmitted to the third communications device and iii) the amount of data to be transmitted to the second communications device.

8. The method of claim 1 , further comprising:

receiving from the second communications device a request for a particular beam mode, said requested beam mode being one of a broad beam mode or a narrow beam mode;

determining if the preferred beam mode indicates a beam mode which is different from the requested beam mode; and

changing the preferred beam mode to the requested beam mode when the use of a beam corresponding to the requested beam mode will satisfy power or QoS requirements of the second communications device.

9. The method of claim 8 , wherein, receiving from the second communications device a request for a particular beam mode includes:

receiving from the second communications device a requested beam mode indicator indicating one of a broad beam mode and a narrow beam mode.

10. The method of claim 1 , wherein said signal quality information is feedback information sent from the second communications device to the first communications device.

11. The method of claim 1 , wherein said signal quality information is feedback information that is based on measurements of reference signals transmitted, by the first communications device, on beams.

12. The method of claim 1 , wherein the first communications device is a base station.

13. A first communications device, comprising:

an antenna array including antenna elements;

receiver circuitry coupled to said antenna elements, said receiver circuitry being configured to receive, signal quality information from a second communications device, for a first period of time corresponding to beams transmitted by the first communications device;

a processor configured to:

i) identify a set of X broad beams having the best reported quality, said set of X beams including one or more broad beams;

ii) identify a set of Y narrow beams having the best reported quality, said set of Y beams including one or more narrow beams;

iii) determine a first quality variance for the best Y beam for the first period of time; and

iv) determine a preferred beam mode based on at least the first quality variance, said preferred beam mode being one of a broad beam mode or a narrow beam mode, wherein determining a preferred beam mode includes: determining if the first quality variance is greater than a first threshold, and when it is determined that the first quality variance is greater than the first threshold said step determining a preferred beam mode is further based on: i) a first quality indicator value for the best beam in said set of Y narrow beams, said first quality indicator value generated from multiple reported signal quality values, corresponding to the best Y beam, included in said received signal quality information; and ii) a second quality indicator value for the best beam in said set of X broad beams, said second quality indicator value generated from multiple reported signal quality values, corresponding to the best X beam, included in said received signal quality information; and

transmitter circuitry coupled to said antenna elements, said transmitter circuitry configured to transmit information indicating the preferred beam mode and beam to the second communications device.

14. The first communications device of claim 13 , wherein the processor is further configured, as part of determining the preferred beam mode to:

set the preferred beam mode to narrow beam mode when it is determined that the first quality variance is not greater than the first threshold.

15. The first communications device of claim 14 , where said first quality variance is for a time period of 5 milliseconds or less.

16. The first communications device of claim 13 , wherein the processor is further configured, when it is determined that the first quality variance is greater than the first threshold, to:

determine a difference between the first quality indicator value and the second quality indicator value;

determine if the difference is below a second threshold; and

set the preferred beam mode to narrow beam mode when it is determined that difference is not below the second threshold.

17. The first communications device of claim 16 , wherein the processor is further configured, when it is determined that the first quality variance is greater than the first threshold and below the second threshold, to:

determine if the quality variance of the best beam in the set of X broad beams is below a third threshold; and

in response to determining that the quality variance of the best beam in the set of X broad beams is below the third threshold setting the preferred beam mode to broad beam mode; and

otherwise setting the preferred beam mode to narrow beam mode.

18. The first communications device of claim 14 , wherein the processor is further configured to, prior to transmission of the preferred beam mode to the second device:

make a decision whether or not to modify the preferred beam mode prior to transmitting of the preferred beam mode to the second communications device, said making of a decision including:

determining if there is a broad beam covering an area in which the second communications device is located and a third communications device is located, said broad beam covering said area being a candidate beam;

if it is determined that there is no broad beam covering an area in which the second communications device is located and a third communications device is located leaving the preferred beam mode and beam unchanged; and

if it is determined that there is a broad beam covering an area in which the second communications device is located and a third communications device is located, the method further comprising:

making a decision as to whether to set the beam mode to broad beam mode and the preferred beam to the candidate beam based on one or more of: i) traffic requirements for traffic to be transmitted to at least one of the second and third communications devices; ii) the amount of data to be transmitted to the third communications device and iii) the amount of data to be transmitted to the second communications device.

19. The first communications device of claim 18 , wherein making the decision as to whether to set the beam mode to broad beam mode and the preferred beam to the candidate beam includes:

deciding to set the beam mode to broad beam mode and the preferred beam to the candidate beam based on one or more of: traffic requirements for traffic to be transmitted to at least one of the second and third communications devices; ii) the amount of data to be transmitted to the third communications device and iii) the amount of data to be transmitted to the second communications device.

20. The first communications device of claim 13 ,

wherein said receiver circuitry is further configured to receive from the second communications device a request for a particular beam mode, said requested beam mode being one of a broad beam mode or a narrow beam mode; and

wherein the processor is further configured to:

determine if the preferred beam mode indicates a beam mode which is different from the requested beam mode; and

change the preferred beam mode to the requested beam mode when the use of a beam corresponding to the requested beam mode will satisfy power or QoS requirements of the second communications device.

21. A non-transitory computer readable medium including processor executable instructions which when executed by a processor in a first communications device, control the first communications device to:

receive, from a second communications device, signal quality information for a first period of time corresponding to beams transmitted by the first communications device;

identify a set of X broad beams having the best reported quality, said set of X beams including one or more broad beams;

identify a set of Y narrow beams having the best reported quality, said set of Y beams including one or more narrow beams;

determine a first quality variance for the best Y beam for the first period of time; and

determine a preferred beam mode based on at least the first quality variance, said preferred beam mode being one of a broad beam mode or a narrow beam mode, wherein determining the preferred beam mode includes:

determining if the first quality variance is greater than a first threshold; and

when it is determined that the first quality variance is greater than the first threshold said step determining a preferred beam mode is further based on: i) a first quality indicator value for the best beam in said set of Y narrow beams, said first quality indicator value generated from multiple reported signal quality values, corresponding to the best Y beam, included in said received signal quality information; and ii) a second quality indicator value for the best beam in said set of X broad beams, said second quality indicator value generated from multiple reported signal quality values, corresponding to the best X beam, included in said received signal quality information.