Method and device for random access configuration

1. A method at a network device, comprising:

in response to receiving a handover request for handing over a terminal device from a source cell managed by a further network device to a target cell managed by the network device, determining a configuration for a random access preamble transmission, the configuration indicating the number of times of transmission of the random access preamble from the terminal device; and

transmitting the configuration for the random access preamble transmission to the further network device.

2. The method of claim 1 , wherein determining the configuration for the random access preamble transmission comprises:

obtaining a capability of the terminal device from the handover request, the capability indicating whether the terminal device has a reciprocity capability of deriving an uplink transmission beam based on a received downlink transmission beam; and

determining the configuration for the random access preamble transmission based on the capability of the terminal device.

3. The method of claim 2 , wherein determining the configuration for the random access preamble transmission based on the capability of the terminal device comprises:

in response to the terminal device having the reciprocity capability, configuring one transmission of the random access preamble; and

in response to the terminal device lacking the reciprocity capability, configuring a plurality of transmissions of the random access preamble.

4. The method of claim 1 , wherein determining the configuration for the random access preamble transmission comprises:

determining a radio condition of a link between the terminal device and the network device; and

determining the configuration for the random access preamble transmission based on the radio condition.

5. The method of claim 4 , wherein determining the radio condition comprises:

obtaining quality information of the link measured at the terminal device, the quality information including at least one of: a signal strength, a signal power, a signal quality, a signal to noise ratio, and a signal to interference plus noise ratio; and

determining the radio condition based on the quality information of the link.

6. The method of claim 4 , wherein determining the configuration for the random access preamble transmission based on the radio condition comprises:

in response to the radio condition exceeding a condition threshold, configuring one transmission of the random access preamble; and

in response to the radio condition being less than a condition threshold, configuring a plurality of transmissions of the random access preamble.

7. The method of claim 4 , wherein determining the configuration for the random access preamble transmission based on the radio condition comprises:

in response to the radio condition being less than a first threshold, configuring a first number of transmissions of the random access preamble;

in response to the radio condition exceeding the first threshold and being less than a second threshold, configuring a second number of transmissions of the random access preamble; and

in response to the radio condition exceeding the second threshold, configuring a third number of transmissions of the random access preamble,

wherein the second number is two times of the third number, and the first number is four times of the third number.

8. The method of claim 1 , wherein determining the configuration for the random access preamble transmission comprises:

determining a priority level of at least one of: a capability of the terminal device, a radio condition of a link between the terminal device and the network device, and network throughput; and

determining the configuration for the random access preamble transmission based on the priority level.

9. The method of claim 1 , wherein transmitting the configuration for the random access preamble transmission to the further network device comprises:

including the configuration for the random access preamble transmission in a handover request acknowledgement message; and

transmitting the handover request acknowledgement message to the further network device.

10. A network device, comprising:

a processor; and

a memory, the memory containing program including instructions executable by the processor, the processor being configured to cause the network device to:

in response to receiving a handover request for handing over a terminal device from a source cell managed by a further network device to a target cell managed by the network device, determine a configuration for a random access preamble transmission, the configuration indicating the number of times of transmission of the random access preamble from the terminal device; and

transmit the configuration for the random access preamble transmission to the further network device.

11. The device of claim 10 , wherein the processor being further configured to cause the network device to:

obtain a capability of the terminal device from the handover request, the capability indicating whether the terminal device has a reciprocity capability of deriving an uplink transmission beam based on a received downlink transmission beam; and

determine the configuration for the random access preamble transmission based on the capability of the terminal device.

12. The device of claim 11 , wherein the processor being further configured to cause the network device to:

in response to the terminal device having the reciprocity capability, configure one transmission of the random access preamble; and

in response to the terminal device lacking the reciprocity capability, configure a plurality of transmissions of the random access preamble.

13. The device of claim 10 , wherein the processor being further configured to cause the network device to:

determine a radio condition of a link between the terminal device and the network device; and

determine the configuration for the random access preamble transmission based on the radio condition.

14. The device of claim 13 , wherein the processor being further configured to cause the network device to:

obtain quality information of the link measured at the terminal device, the quality information including at least one of: a signal strength, a signal power, a signal quality, a signal to noise ratio, and a signal to interference plus noise ratio; and

determine the radio condition based on the quality information of the link.

15. The device of claim 10 , wherein the processor being further configured to cause the network device to:

determine a priority level of at least one of: a capability of the terminal device, a radio condition of a link between the terminal device and the network device, and network throughput; and

determine the configuration for the random access preamble transmission based on the priority level.

16. A terminal device, comprising:

a processor; and

a memory, the memory containing program including instructions executable by the processor, the processor being configured to cause the terminal device to:

receive a configuration for a random access preamble transmission, the configuration indicating the number of times of transmission of the random access preamble from the terminal device, and the configuration being determined in response to a handover request for handing over the terminal device from a source cell to a target cell; and

transmit the random access preamble for the indicated number of times to a network device managing the target cell in a random access procedure to the target cell.

17. The device of claim 16 , wherein the configuration for the random access preamble transmission is determined based on at least one of:

a capability of the terminal device, the capability indicating whether the terminal device has a reciprocity capability of deriving an uplink transmission beam based on a received downlink transmission beam;

a radio condition of a link between the terminal device and the network device; and

network throughput.

18. The device of claim 17 , wherein if the terminal device has the reciprocity capability, the configuration for the random access preamble transmission indicates one transmission of the random access preamble; and

if the terminal device lacks the reciprocity capability, the configuration for the random access preamble transmission indicates a plurality of transmissions of the random access preamble.

19. The device of claim 17 , wherein if the radio condition exceeding a condition threshold, the configuration for the random access preamble transmission indicates one transmission of the random access preamble; and

if the radio condition being less than a condition threshold, the configuration for the random access preamble transmission indicates a plurality of transmissions of the random access preamble.