Reporting of a beam index in a communications network

1 . A method for reporting a beam index, the method being performed by a wireless device, the wireless device comprising a controller, a beam predictor, and a radio transceiver, the method comprising:

obtaining, at the controller, an indication that the wireless device is to report the beam index to an access network node, wherein the beam index represents a beam to be used by the access network node for communicating with the wireless device; and in response thereto:

obtaining, at the controller, the beam index from the beam predictor by providing information of current geographic position of the wireless device and current time as input to the beam predictor,

wherein the beam predictor has been trained with tuples that associate at least different geographical positions and different points in time with different beam indices, and wherein the beam predictor predicts the beam index based on the current geographic position and the current time and wherein a second beam index is predicted and reported by the radio transceiver to the access network node when the signal strength value for the beam is below a threshold value;

obtaining, by the controller, verification from the beam predictor that the beam predictor has been trained before the information of the current geographic position of the wireless device and the current time is provided as input to the beam predictor, and

wirelessly reporting, using the radio transceiver, the beam index as obtained from the beam predictor to the access network node,

wherein the tuples associate the different geographical positions and the different points in time with a signal strength value for a respective beam of the different beam indices.

2 . The method according to claim 1 , wherein the indication as obtained specifies the current time and that the wireless device is located at the current geographic position.

3 . The method according to claim 1 , wherein the indication is obtained at the controller from the radio transceiver upon the radio transceiver having received a reference signal from the access network node.

4 . The method according to claim 3 , further comprising:

measuring received power on the reference signal only as received in the beam given by the beam index.

5 . The method according to claim 1 , wherein the beam predictor predicts the signal strength value for the beam of the beam index, and wherein the signal strength value is reported to the access network node together with the beam index.

6 . The method according to claim 1 , wherein the beam index is a first beam index and wherein the tuples associate the different geographical positions and the different points in time also with a signal strength value for a respective beam of the different beam indices.

7 . The method according to claim 1 , wherein the beam index is predicted by the beam predictor based on at least one of: predicted geographic position towards which the wireless device is moving, physical cell identity (PCI) of the access network node, current travelling speed of the wireless device, or timing advance information of communication between the wireless device and the access network node.

8 . The method according to claim 1 , wherein training of the beam predictor is based on measurements on reference signals as previously received by the radio transceiver.

9 . The method according to claim 1 , wherein training of the beam predictor is based on at least one of: physical cell identity (PCI) of the access network node, the current geographic position of the wireless device, predicted geographic position towards which the wireless device is moving, current travelling speed of the wireless device, time of day, or timing advance information of communication between the wireless device and the access network node.

10 . The method according to claim 1 , wherein training of the beam predictor is based on feedback in terms of one of: packet loss per beam used for communication between the wireless device and the access network node, radio link failure indications per beam used for communication between the wireless device and the access network node, or amount of retransmissions per beam used for communication between the wireless device and the access network node.

11 . The method according to claim 1 , wherein training of the beam predictor is based on running pattern recognition on observations of which beam indices that, based on measurements on received reference signals, have been reported by the radio transceiver for different combinations of geographical positions and points in time.

12 . A wireless device for reporting a beam index, the wireless device comprising processing circuitry, the processing circuitry being configured to cause the wireless device to:

obtain an indication that the wireless device is to report the beam index to an access network node, wherein the beam index represents a beam to be used by the access network node for communicating with the wireless device; and in response thereto:

obtain the beam index from a beam predictor by providing information of current geographic position of the wireless device and current time as input to the beam predictor, wherein the beam predictor has been trained with tuples that associate at least different geographical positions and different points in time with different beam indices, and wherein the beam predictor predicts the beam index based on the current geographic position and the current time and wherein a second beam index is predicted and reported by the radio transceiver to the access network node when the signal strength value for the beam is below a threshold value; obtaining, by the controller, verification from the beam predictor that the beam predictor has been trained before the information of the current geographic position of the wireless device and the current time is provided as input to the beam predictor, and

wirelessly report the beam index as obtained from the beam predictor to the access network node,

wherein the tuples associate the different geographical positions and the different points in time with a signal strength value for a respective beam of the different beam indices.

13 . A non-transitory computer-readable medium having stored thereon computer-executable instructions that, when executed by a computer, cause the computer to execute operations, the operations comprising:

obtain an indication that the wireless device is to report the beam index to an access network node, wherein the beam index represents a beam to be used by the access network node for communicating with the wireless device; and in response thereto:

obtain the beam index from a beam predictor by providing information of current geographic position of the wireless device and current time as input to the beam predictor, wherein the beam predictor has been trained with tuples that associate at least different geographical positions and different points in time with different beam indices, and wherein the beam predictor predicts the beam index based on the current geographic position and the current time and wherein a second beam index is predicted and reported by the radio transceiver to the access network node when the signal strength value for the beam is below a threshold value; obtaining, by the controller, verification from the beam predictor that the beam predictor has been trained before the information of the current geographic position of the wireless device and the current time is provided as input to the beam predictor, and

wirelessly report the beam index as obtained from the beam predictor to the access network node,

wherein the tuples associate the different geographical positions and the different points in time with a signal strength value for a respective beam of the different beam indices.