Communication based on plurality of SIMs

1. A method for a wireless communication device to perform communication based on a plurality of Subscriber Identification Modules (SIMs),

transmitting a request message to a first network node of a second network,

wherein the request message includes first information related to a plurality of SIMs, and

wherein the wireless communication device is performing communication in a first network or monitoring paging in the first network; and

receiving an accept message for the request message from the first network node of the second network,

wherein the first information related to the plurality of SIMs is used for the first network node of the second network to transmit a notification message to the wireless communication device via the first network, through a second network node of a second network.

2. The method of claim 1 , further comprising:

receiving the notification message transmitted by a first network node of the second network from a second network node of the second network through the first network,

wherein the notification message includes information on a service type related to downlink data for the wireless communication device in the second network.

3. The method of claim 2 , further comprising:

determining whether to transmit a service request message to the first network node of the second network through 3rd Generation Partnership Project (3GPP) access based on the information on the service type.

4. The method of claim 3 , further comprising:

transmitting, via 3GPP access of the second network, a service request message to the first network node of the second network based on that the decision to transmit the service request message.

5. The method of claim 3 , further comprising:

based on the decision not to transmit the service request message, transmitting a response message to the notification message to the second network node of the second network via the first network.

6. The method of claim 2 ,

wherein the request message is one of a registration request message, a Tracking Area Update (TAU) request message, or an attach request message.

7. The method of claim 1 ,

wherein the acceptance message includes second information associated with a plurality of SIMs indicating that the first network node of the second network will transmit a notification message via the first network.

8. The method of claim 1 ,

wherein the first network node of the second network is an Access and Mobility Management Function (AMF) node of the second network,

wherein the second network node of the second network is a Non-3GPP Inter Working Function (N3IWF) node of the second network,

wherein the request message is transmitted to the first network node of the second network via the UPF node of the first network and the second network node of the second network, based on using the PDU session of the first network.

9. The method of claim 1 ,

wherein the wireless communication device includes the plurality of SIMs,

wherein the plurality of SIMs includes a first SIM related to the first network and a second SIM related to the second network.

10. A method for a wireless communication device to perform communication based on a plurality of Subscriber Identification Modules (SIMs),

transmitting a request message to a first network node of a second network,

wherein the request message includes first information and second information related to a plurality of SIMs,

wherein the wireless communication device is performing communication in a first network or monitoring paging in the first network, and

wherein the second information related to the plurality of SIMs is number information of a SIM related to the first network among the plurality of SIMs; and

receiving an accept message for the request message from the first network node of the second network;

wherein the first information and the second information related to the plurality of SIMs are used for the first network node of the second network to transmit a Short Message Service (SMS) message including a notification message to the wireless communication device, when downlink data for the wireless communication device exists in the second network.

11. The method of claim 10 , further comprising:

receiving the notification message, transmitted by a first network node of the second network, from a second network node of the second network,

wherein the notification message includes information on a service type related to downlink data for the wireless communication device in the second network and second information related to the plurality of SIMs.

12. The method of claim 10 , further comprising:

wherein the first network node of the second network is an Access and Mobility Management Function (AMF) node or Mobility Management Entity (MME) node of the second network,

wherein the second network node of the second network is an Application Function (AF) node, a Network Exposure Function (NEF) node, or a service capability exposure function (SCEF) node of the second network,

wherein the notification message is transmitted by a first network node of the second network via a second network node of the second network and a Short Message Service-Service Center (SMS-SC) node of the second network.

13. The method of claim 11 , further comprising:

determining whether to transmit a service request message to the first network node of the second network through 3rd Generation Partnership Project (3GPP) access based on the information on the service type.

14. The method of claim 13 ,

transmitting, via 3GPP access of the second network, a service request message to the first network node of the second network based on determining to transmit the service request message.

15. The method of claim 13 ,

based on the decision not to transmit the service request message, transmitting an SMS message including a response message to the notification message to the second network node of the second network.

16. A method in which a first network node of a second network performs communication based on a plurality of Subscriber Identification Modules (SIMs), the method comprising:

receiving a request message from a wireless communication device;

wherein the request message includes first information related to a plurality of SIMs; and

transmitting an accept message for the request message to the wireless communication device,

when downlink data for the wireless communication device exists in the second network, the first information related to the plurality of SIMs is information requesting to transmit a notification message to the wireless communication device through the first network via a second network node of a second network.

17. The method of claim 16 ,

receiving a message indicating that downlink data for the wireless communication device exists from a Session Management Function (SMF) node or a Serving Gateway (S-GW) node of the second network; and

transmitting the notification message to the wireless communication device through the first network via a second network node of the second network based on the existence of downlink data for the wireless communication device, and,

wherein the notification message includes information on a service type related to the downlink data.

18. The method of claim 17 , further comprising:

receiving a response message for the notification message from a second network node of the second network through the first network.

19. The method of claim 17 , further comprising:

receiving a service request message from the wireless communication device via 3GPP access of the second network.

20. The method of claim 16 ,

wherein the acceptance message includes

second information related to a plurality of SIMs indicating that the first network node of the second network will transmit a notification message via the second network node of the second network.