Mobile secondary number short message service

After the application for the secondary number is successful, the platform simulates the MSC/VLR of the secondary number to send a location update message to the HLR of the secondary number, and registers the one-card multi-number short message platform as the MSC/VLR where the secondary number is currently located, so that when other users send short messages to the secondary number, the location of the secondary number found from HLR is the one-card multi-number short message platform, and the short message is sent through MT.