Patent ID: 6920320

Claim:
A method for preserving call-state information on a wireless communication system having a plurality of cells for providing wireless communication services to wireless terminals, and a first and second application processor each having host memories, the method comprising: running a first Radio Control Software (RCS) application instance in active operation on the first application processor communicating with a group of the cells via network-based active call facilities paths for handling the radio control signaling and Office Administration & Maintenance (OA&M) of the group of the cells; running a second RCS application instance in standby operation on the second application processor; replicating stable call call-state information between the first processor and the second processor via a network connection before an outage of at least one of the first processor and the first RCS application instance; transitioning the second RCS application instance to an active state for handling the radio control signaling of the group of the cells thereby avoiding a service interruption for the stable calls previously handled by the active first RCS application instance; performing a transient clear after the outage to drop transient calls in existence at the time of the outage; and forming network-based active call facilities paths between the second RCS application instance and the group of the cells.