Acquiring timing advance value

1 . A terminal device comprising:

at least one processor; and

at least one memory storing instructions that, when executed by the at least one processor, cause the terminal device being connected with a serving cell or a primary cell of the terminal device, at least to:

transmit a signal to a network device supporting a non-serving cell or a secondary cell of the terminal device, wherein a physical cell identifier (PCI) of the non-serving cell is different from a PCI of the serving cell;

start, based on the transmission of the signal, a timer at the terminal device for obtaining a timing advance (TA) value associated with the non-serving cell or the secondary cell; and

acquire, while the timer is running, the TA value associated with the non-serving cell or the secondary cell,

wherein the terminal device is caused to:

receive, from the serving cell or the primary cell, a response to the signal, wherein the response comprises the TA value associated with the non-serving cell or the secondary cell; and

monitor, while the timer is running and on a UE dedicated search space set of the serving cell or the primary cell, a physical downlink control channel associated with the response to the signal, using a cell radio network temporary identifier.

2 . The terminal device of claim 1 , wherein the terminal device is caused to monitor, while the timer is running and on a Type1-physical downlink control channel (PDCCH) common search space set of the serving cell or the primary cell, a physical downlink control channel associated with the response to the signal, using a cell radio network temporary identifier.

3 . The terminal device of claim 1 , wherein the terminal device is caused to stop the timer in response to the reception of the response to the signal.

4 . The terminal device of claim 1 , wherein the terminal device is caused to retransmit the signal to the network device in case the timer expires and the response is not received.

5 . The terminal device of claim 1 , wherein the terminal device is caused to start the timer upon the transmission of the signal.

6 . The terminal device of claim 1 , wherein the terminal device is caused to postpone the start of the timer by a time delay upon the transmission of the signal.

7 . The terminal device of claim 6 , wherein the time delay is applied to one of the following:

a set of cells; or a cell among a plurality of cells.

8 . The terminal device of claim 6 , wherein the time delay is configured as a common time delay for a frequency layer via at least one of the following:

system information of the serving cell or the primary cell, or

signaling dedicated to the terminal device.

9 . The terminal device of claim 6 , wherein the time delay is indicated via dedicated signaling for configuring the time delay for the terminal device.

10 . The terminal device of claim 6 , wherein the time delay is associated with a value of the timer.

11 . The terminal device of claim 6 , wherein the terminal device is caused to: receive, from the serving cell or the primary cell, a PDCCH order triggering the transmission of the signal and indicating the time delay.

12 . The terminal device of claim 1 , wherein the terminal device is caused to: prior to transmitting the signal to the network device, receive a configuration of the timer from the serving cell or the primary cell.

13 . The terminal device of claim 1 , wherein the signal is a random access preamble.

14 . The terminal device of claim 13 , wherein the timer corresponds to a random access response window.

15 . The terminal device of claim 1 , wherein the signal is a sounding reference signal.

16 . A method comprising:

transmitting, by a terminal device being connected with a serving cell or a primary cell of the terminal device, a signal to a network device supporting a non-serving cell or a secondary cell of the terminal device, wherein a physical cell identifier (PCI) of the non-serving cell is different from a PCI of the serving cell;

starting, by the terminal device and based on the transmission of the signal, a timer at the terminal device for obtaining a timing advance (TA) value associated with the non-serving cell or the secondary cell; and

acquiring, by the terminal device and while the timer is running, the TA value associated with the non-serving cell or the secondary cell,

wherein the method further comprises:

receiving, from the serving cell or the primary cell, a response to the signal, wherein the response comprises the TA value associated with the non-serving cell or the secondary cell; and

monitoring, while the timer is running and on a UE dedicated search space set of the serving cell or the primary cell, a physical downlink control channel associated with the response to the signal, using a cell radio network temporary identifier.

17 . A terminal device comprising:

at least one processor; and

at least one memory storing instructions that, when executed by the at least one processor, cause the terminal device being connected with a serving cell or a primary cell of the terminal device, at least to:

transmit a signal to a network device supporting a non-serving cell or a secondary cell of the terminal device, wherein a physical cell identifier (PCI) of the non-serving cell is different from a PCI of the serving cell;

start, based on the transmission of the signal, a timer at the terminal device for obtaining a timing advance (TA) value associated with the non-serving cell or the secondary cell; and

acquire, while the timer is running, the TA value associated with the non-serving cell or the secondary cell,

wherein the terminal device is caused to postpone the start of the timer by a time delay upon the transmission of the signal,

wherein the time delay is configured as a common time delay for a frequency layer via at least one of the following:

system information of the serving cell or the primary cell, or

signaling dedicated to the terminal device.