Wireless communications apparatus and methods
A method of operating a first non-terrestrial network part supporting a plurality of spot beams providing corresponding coverage areas in a wireless telecommunications network, the method comprising: communicating with a communications device in a first coverage area associated with a first spot beam of the first non-terrestrial network part: identifying a new coverage area for the communications device, the new coverage area corresponding to a coverage area of a second spot beam different from the first spot beam, and implementing a mobility procedure for the communications device; wherein, if the second spot beam is supported by the first non-terrestrial network part, the mobility procedure is a first mobility procedure and if the second spot beam is supported by a second non-terrestrial network part different from the first non-terrestrial network part the mobility procedure is a second mobility procedure different from the first mobility procedure.
1. A method for an infrastructure equipment of a wireless telecommunications network, the wireless telecommunications network comprising a base station and a non-terrestrial network part, the non-terrestrial network part transmitting one or more beams to provide a wireless access interface for transmitting signals to and receiving signals representing data from a communications device within a coverage region of a cell or a spot beam, the method comprising:
determining a location of the communications device;
determining the coverage region of the cell or the spot beam;
determining a relative motion, relative to the communications device, of the coverage region of the cell or the spot beam;
determining, at the non-terrestrial network part, a change in the coverage area of the spot beam based on a trajectory of the non-terrestrial network part; and
based on the location and the relative motion, initiating a cell change of the communications device.
2. The method of claim 1 , wherein the coverage region of the cell varies over time in accordance with a motion of the non-terrestrial network part with respect to the surface of the Earth.
3. The method of claim 1 , wherein the relative motion is determined based on the change in the coverage region of the cell or the spot beam.
4. The method of claim 1 , wherein a trajectory of the non-terrestrial network part is such that the coverage region of the cell or the spot beam is substantially constant over a time period.
5. The method of claim 1 , wherein the communications device is acting as a relay device for one or more terminal devices, each of the one or more terminal devices being in one of an RRC connected mode, an RRC idle state or an RRC inactive state.
6. The method of claim 1 , further comprising:
transmitting to the communications device an indication that the communications device is to change a serving cell of the communications device when the communications device determines that one or more conditions are satisfied.
7. The method of claim 1 , wherein the infrastructure equipment is the non-terrestrial network part.
8. The method of claim 1 , wherein the non-terrestrial network part comprises a satellite or an airborne vehicle.
9. The method of claim 1 , wherein the communications device is in an RRC connected mode, and initiating a cell change of the communications device comprises initiating a handover of the communications device.
10. An infrastructure equipment for use in a wireless telecommunications network, the wireless telecommunications network comprising a base station and a non-terrestrial network part, the non-terrestrial network part transmitting one or more beams to provide a wireless access interface for transmitting signals to and receiving signals representing data from a communications device within a coverage region of a cell, the infrastructure equipment operatively coupled to one or more of the base station and the non-terrestrial network part, the infrastructure equipment comprising processor circuitry and transceiver circuitry configured to operate together such that the infrastructure equipment is operable to:
determine a location of the communications device,
determine the coverage region of the cell or the spot beam,
determine a relative motion, relative to the communications device, of the coverage region of the cell or the spot beam,
determine, at the non-terrestrial network part, a change in the coverage area of the spot beam based on a trajectory of the non-terrestrial network part, and
based on the location and the relative motion, initiate a cell change of the communications device.
11. The infrastructure equipment of claim 10 , wherein the infrastructure equipment is the non-terrestrial network part.
12. The infrastructure equipment of claim 10 , wherein the coverage region of the cell varies over time in accordance with a motion of the non-terrestrial network part with respect to the surface of the Earth.
13. The infrastructure equipment of claim 10 , wherein the relative motion is determined based on the change in the coverage region of the cell or the spot beam.
14. The infrastructure equipment of claim 10 , wherein a trajectory of the non-terrestrial network part is such that the coverage region of the cell or the spot beam is substantially constant over a time period.
15. The infrastructure equipment of claim 10 , wherein the communications device is acting as a relay device for one or more terminal devices, each of the one or more terminal devices being in one of an RRC connected mode, an RRC idle state or an RRC inactive state.
16. The infrastructure equipment of claim 10 , wherein the infrastructure equipment is further operable to:
transmit to the communications device an indication that the communications device is to change a serving cell of the communications device when the communications device determines that one or more conditions are satisfied.
17. The infrastructure equipment of claim 10 , wherein the non-terrestrial network part comprises a satellite or an airborne vehicle.
18. The infrastructure equipment of claim 10 , wherein the communications device is in an RRC connected mode, and initiating a cell change of the communications device comprises initiating a handover of the communications device.