Method for performing communication by using non-terrestrial network and apparatus thereof

1. A method for performing communication using a non-terrestrial network by a user equipment (UE), the method comprising:

receiving system information comprising reference round trip delay offset information of a non-terrestrial network cell;

performing a random access procedure in the non-terrestrial network cell;

receiving configuration information for performing communication using the non-terrestrial network cell; and

controlling a discontinuous reception (DRX) operation based on the configuration information,

wherein the reference round trip delay offset information is used to calculate a round trip delay between the UE and a network node in the non-terrestrial network cell, and

wherein the performing the random access comprises:

transmitting a message 3 (MSG 3) for a contention-based random access procedure;

starting a timer for contention resolution when a time according to the round trip delay between the UE and the network node calculated using the reference round trip delay offset information elapses after transmission of the message 3.

2. The method of claim 1 , wherein the controlling the discontinuous reception (DRX) operation comprises:

when a scheduling request is transmitted and pending on PUCCH (Physical Uplink Control Channel), controlling an active time to start when the time corresponding to the round trip delay between UE and the network node elapses after the scheduling request is transmitted.

3. The method of claim 1 , wherein the configuration information comprises a discontinuous reception HARQ RTT (drx HARQ Round Trip Time) timer, and

the discontinuous reception HARQ RTT (drx HARQ Round Trip Time) timer is configured using the reference round trip delay between the UE and the network node.

4. The method of claim 3 , wherein the discontinuous reception HARQ RTT (drx HARQ Round Trip Time) timer disabled when a disable indication for a Downlink HARQ feedback operation is received.

5. A method for performing communication using a non-terrestrial network with a user equipment (UE) by a network node, the method comprising:

transmitting system information comprising reference round trip delay offset information of a non-terrestrial network cell;

performing a random access procedure with the UE in the non-terrestrial network cell; and

transmitting configuration information for performing communication using the non-terrestrial network cell,

wherein the reference round trip delay offset information is used to calculate a round trip delay between the UE and a network node in the non-terrestrial network cell, and

wherein the performing the random access comprises:

receiving a message 3 (MSG 3) from the UE for a contention-based random access procedure, and

the UE starts a timer for contention resolution when a time according to the round trip delay between the UE and the network node calculated using the reference round trip delay offset information elapses after transmission of the message 3.

6. The method of claim 5 , wherein the UE comprises:

controlling the discontinuous reception (DRX) operation based on the configuration information,

when a scheduling request is transmitted and pending on PUCCH (Physical Uplink Control Channel), controlling an active time to start when the time corresponding to the round trip delay between UE and the network node elapses after the scheduling request is transmitted.

7. The method of claim 5 , wherein the configuration information comprises a discontinuous reception HARQ RTT (drx HARQ Round Trip Time) timer, and

the discontinuous reception HARQ RTT (drx HARQ Round Trip Time) timer is configured using the reference round trip delay between the UE and the network node.

8. The method of claim 7 , wherein the discontinuous reception HARQ RTT (drx HARQ Round Trip Time) timer disabled when a disable indication for a Downlink HARQ feedback operation is received.

9. A user equipment (UE) performing communication using a non-terrestrial network, the UE comprising:

a receiver configured to receive system information comprising reference round trip delay offset information of a non-terrestrial network cell and configuration information for performing communication using the non-terrestrial network cell; and

a controller configured to perform a random access procedure in the non-terrestrial network cell and control a discontinuous reception (DRX) operation based on the configuration information,

wherein the reference round trip delay offset information is used to calculate a round trip delay between the UE and a network node in the non-terrestrial network cell, and

further comprises a transmitter configured to transmit a message 3 (MSG 3) for a contention-based random access procedure,

wherein the controller start a timer for contention resolution when a time according to the round trip delay between the UE and the network node calculated using the reference round trip delay offset information elapses after transmission of the message 3.

10. The UE of claim 9 , when a scheduling request is transmitted and pending on PUCCH (Physical Uplink Control Channel),

wherein the controller configured to control an active time to start when the time corresponding to the round trip delay between UE and the network node elapses after the scheduling request is transmitted.

11. The UE of claim 9 , wherein the configuration information comprises a discontinuous reception HARQ RTT (drx HARQ Round Trip Time) timer, and

the discontinuous reception HARQ RTT (drx HARQ Round Trip Time) timer is configured using the reference round trip delay between the UE and the network node.

12. The UE of claim 11 , wherein the discontinuous reception HARQ RTT (drx HARQ Round Trip Time) timer disabled when a disable indication for a Downlink HARQ feedback operation is received.