Method and apparatus to control handoff between different wireless systems

A first base station system that performs wireless communications with a mobile station according to a first protocol, the first base station system comprising:

• an interface to a second base station system that performs wireless communications with the mobile station according to a second, different protocol;
• and
• a controller to communicate bearer traffic for a packet-switched communications session with the mobile station,
• the controller to further determine that the handoff is required from the first base station to the second base station, and in response to determining the handoff is required, send messaging to the second base station system through the interface to perform a handoff of the packet-switched communications session from the first base station system to the second base station system.

An article comprising at least one storage medium containing instructions that when executed cause a first base station system to:

• communicate signaling according to a first protocol with a mobile station to establish a packet-switched communications session between the mobile station and another endpoint;
• determine if a handoff is required to a second base station system that performs wireless communications with the mobile station according to a second, different protocol;
• and
• in response to determining that the handoff is required, send messaging to the second base station system through a link between the first and second base station systems to perform the handoff.