Patent ID: 8351931

Claim:
A method for roaming retry under pre-paging mode, comprising: during a pre-paging period, a called Mobile Station (MS) moving to a new location area and sending a location update request to a new Visitor Mobile Switching Center/Visitor Location Register (New VMSC/VLR); after receiving the location update request, the New VMSC/VLR sending a update location area message to a Home Location Register (HLR); after receiving the update location area message, the HLR sending a Send Routing Information (SRI) Ack message including a Roaming Retry Indication identifier to a Gateway Mobile Switching Center (GMSC); and after receiving the SRI Ack message, the GMSC triggering a roaming retry procedure according to the Roaming Retry Indication identifier in the SRI Ack message, and completing a subsequent calling flow.