Communication based on plurality of SIMs

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.

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.