Communications methods and apparatus using multiple beams
Methods and apparatus for facilitating the use of a plurality of antenna beams for communications purposes are described. In at least some embodiments beam priority information is periodically exchanged. Multiple timers are used to ensure beam information is exchanged at intervals intended to facilitate reliable beam synchronization and to control switching to one or more alternative beams in a predictable manner in the event beam change information or beam synchronization information is lost. In some but not all embodiments a wideband beam is used to communicate beam synchronization information when synchronization using narrower beams used for normal data communication is lost.
1. A method of operating a second wireless communications device in communications with a first wireless communications device which uses multiple beams for transmission, the method comprising:
transmitting, from the second wireless communications device, a beam change signal to the first wireless communications device indicating the first wireless communications device is to switch to using a second beam indicated in the beam change signal for communications with the second wireless communications device;
setting a wideband beam switch timer when the beam change signal is sent to the first wireless communications device;
monitoring, at the second wireless communications device, for receipt of a signal from the first wireless communications device on said second beam;
determining if, after setting of the wideband beam switch timer, a signal from the first communications device has not been received by expiration of the wideband beam switch timer; and
in response to determining that, after setting of the wideband beam switch timer, a signal from the wireless first communications device has not been received by expiration of the wideband beam switch timer, switching to monitoring a wideband beam for a signal from the first wireless communications device indicating a beam which will be used by the first wireless communications device to transmit to the second wireless communications device.
2. The method of claim 1 , further comprising:
setting, at the second wireless communications device, a channel switch timer when the beam change signal is sent to the first wireless communications device; and
switching back to a previous beam from said second beam in response to said monitoring failing to detect said signal from the first wireless communications device on said second beam by the time said channel switch timer expires.
3. The method of claim 2 , wherein said signal from the first wireless communications device on said second beam for which said monitoring is performed is one of a beam change confirmation signal or a data signal directed to the second wireless communications device.
4. The method of claim 1 , further comprising:
setting a second timer when the beam change signal is sent to the first wireless communications device; and
determining if, after setting of the second timer, a signal from the first wireless communications device has not been received by expiration of the second timer.
5. The method of claim 4 , further comprising:
sending a radio reconnection request to the first wireless communications device in response to determining that, after setting of the second timer, a signal from the first communications device has not been received by expiration of the second timer.
6. A second wireless communications device in communications with a first wireless communications device, which uses multiple beams for transmission, the second wireless communications device comprising:
a transmitter; and
a processor configured to control the second wireless communications device to:
transmit a beam change signal to the first wireless communications device indicating the first wireless communications device should switch to using a second beam for communications with the second wireless communications device;
set a wideband beam switch timer when the beam change signal is sent to the first wireless communications device;
monitor for receipt of a signal from the first wireless communications device on said second beam;
determine if, after setting of the wideband beam switch timer, a signal from the first communications device has not been received by expiration of the wideband beam switch timer; and
switch to monitoring a wideband beam for a signal from the first wireless communications device indicating a beam which will be used by the first wireless communications device to transmit to the second wireless communications device in response to determining that, after setting of the wideband beam switch timer, a signal from the wireless first communications device has not been received by expiration of the wideband beam switch timer.
7. The second wireless communications device of claim 6 ,
wherein the processor is further configured to control the second wireless communications device to:
set a channel switch timer when the beam change signal is sent to the first wireless communications device; and
switch back to a previous beam from said second beam in response to said monitoring failing to detect said signal from the first wireless communications device on said second beam by the time said channel switch timer expires.
8. The second wireless communications device of claim 7 , wherein said signal from the first wireless communications device on said second beam for which said monitoring is performed is one of a beam change confirmation signal or a data signal directed to the second wireless communications device.
9. The second wireless communications device of claim 6 , wherein the processor is further configured to control the second wireless communications device to:
set a second timer when the beam change signal is sent to the first wireless communications device; and
determine if, after setting of the second timer, a signal from the first wireless communications device has not been received by expiration of the second timer.
10. The second wireless communications device of claim 9 , wherein the processor is further configured to control the second wireless communications device to:
send a radio reconnection request to the first wireless communications device in response to determining that, after setting of the second timer, a signal from the first communications device has not been received by expiration of the second timer.
11. The second wireless communications device of claim 6 , wherein the beam change signal commands the first wireless communications device to switch to the second beam.
12. The method of claim 1 , wherein the beam change signal commands the first wireless communications device to switch to the second beam.
13. A non-transitory computer readable medium including computer executable instructions which when executed by a processor of a second wireless communications device, in communications with a first wireless communications device, which uses multiple beams for transmission, cause the second wireless communications device to perform the steps of:
transmitting a beam change signal to the first wireless communications device indicating the first wireless communications device should switch to using a second beam for communications with the second wireless communications device;
setting a wideband beam switch timer when the beam change signal is sent to the first wireless communications device;
monitoring for receipt of a signal from the first wireless communications device on said second beam;
determining if, after setting of the wideband beam switch timer, a signal from the first communications device has not been received by expiration of the wideband beam switch timer; and
switching to monitoring a wideband beam for a signal from the first wireless communications device indicating a beam which will be used by the first wireless communications device to transmit to the second wireless communications device in response to determining that, after setting of the wideband beam switch timer, a signal from the wireless first communications device has not been received by expiration of the wideband beam switch timer.
14. The non-transitory computer readable medium of claim 13 , further comprising instructions which when executed by the processor of the second wireless communications device cause the second wireless communications device to perform the steps of:
setting a channel switch timer when the beam change signal is sent to the first wireless communications device; and
switching back to a previous beam from said second beam in response to said monitoring failing to detect said signal from the first wireless communications device on said second beam by the time said channel switch timer expires.
15. The non-transitory computer readable medium of claim 13 ,
wherein said signal from the first wireless communications device on said second beam for which said monitoring is performed is one of a beam change confirmation signal or a data signal directed to the second wireless communications device.
16. The non-transitory computer readable medium of claim 13 , wherein the beam change signal commands the first wireless communications device to switch to the second beam.