Method and apparatus for connection management in wireless communication system

1. A method performed by a wireless device in a wireless communication system, the method comprising:

registering to a first network and a second network;

establishing a connection with the first network;

monitoring a paging from the second network while maintaining the connection with the first network;

starting a timer upon receiving the paging from the second network;

establishing a connection with the second network;

performing a communication with the second network and maintaining the connection with the first network, while the timer is running;

releasing the connection with the second network after-based on completing the communication with the second network;

after releasing the connection with the second network, determining whether the timer had expired; and

based on the timer having expired, releasing the connection with the first network.

2. The method of claim 1 ,

wherein the wireless device is equipped with a multi-universal subscriber identity module (MUSIM) including a first SIM and a second SIM, and

wherein the registering to the first network and the second network comprises registering to the first network based on the first SIM and the second network based on the second SIM.

3. The method of claim 2 , further comprising:

performing a SIM change from the first SIM to the second SIM upon receiving the paging from the second network,

wherein the performing of the communication with the second network comprises performing the communication with the second network based on the second SIM.

4. The method of claim 2 , further comprising:

after releasing the connection with the second network, performing a SIM change from the second SIM to the first SIM.

5. The method of claim 1 , further comprising:

receiving, from the first network, information for a scheduling gap period,

wherein the scheduling gap period is a period during which:

resources are not scheduled or allocated to the wireless device by the first network; and

the paging from the second network is monitored by the wireless device.

6. The method of claim 1 , wherein the connection with the second network is established while the wireless device maintains the connection with the first network.

7. The method of claim 1 , further comprising:

receiving, from the first network, information for the timer.

8. The method of claim 7 ,

wherein the wireless device stays in a connected mode for the first network before the expiry of the timer, and

wherein releasing of the connection with the first network comprises entering an idle mode or an inactive mode for the first network, from the connected mode.

9. The method of claim 7 , further comprising:

transmitting, to the first network, a request message for a release of the connection with the first network; and

receiving, from the first network, a connection release message as a response for the request message,

wherein the connection release message comprises the information for the timer.

10. The method of claim 7 , wherein the timer is stopped based on a paging being not received until an end of a scheduling gap period.

11. The method of claim 7 , further comprising:

based on a subscriber identity module (SIM) change being performed from a second SIM related to the second network to a first SIM related to the first network before the expiry of the timer:

stopping the timer; and

performing a communication with the first network based on the first SIM.

12. The method of claim 11 ,

wherein the wireless device stays in a connected mode for the first network before the expiry of the timer, and

wherein the communication with the first network based on the first SIM is performed without performing a connection establishment procedure with the first network.

13. The method of claim 1 , wherein the wireless device is in communication with at least one of a user equipment, a network, or autonomous vehicles other than the wireless device.

14. A wireless device in a wireless communication system comprising:

a transceiver;

a memory; and

at least one processor operatively coupled to the transceiver and the memory,

wherein the memory stores instructions that, based on being executed by the at least one processor, perform operations comprising:

registering to a first network and a second network;

establishing a connection with the first network;

monitoring a paging from the second network while maintaining the connection with the first network;

starting a timer upon receiving the paging from the second network;

establishing a connection with the second network;

performing a communication with the second network and maintaining the connection with the first network, while the timer is running;

releasing the connection with the second network based on completing the communication with the second network;

after releasing the connection with the second network, determining whether the timer had expired; and

based on the timer having expired, releasing the connection with the first network.