Patent ID: 7346032
Filing Date: 2008-03-18
Classification: H04W

Abstract:
1. A method of effecting handoff of a mobile station from a first base station in a first cellular communications system controlled by a first mobile switching control station to a second base station in a second cellular system controlled by a second mobile switching control station, said first cellular communications system being a CDMA system, and said second cellular system being a GSM system, the method comprising: measuring at the mobile station a first parameter of a first signal transmitted by said first base station; measuring at the mobile station a second parameter of a second signal transmitted by said second base station, wherein said first and second parameters correspond to signal strength; communicating a signal quality message from the mobile station via the first base station to said first mobile switching control station, when the first and second parameters reach a predetermined condition; generating at the first mobile switching control station an Application Data Delivery Service (ADDS) message containing handoff data, the ADDS message being a type of tunneling mechanism which transparently passes within the CDMA system GSM parameters; communicating the ADDS message from said first mobile switching control station to said mobile station; generating at the mobile station a Mobile Application Protocol (MAP) message containing the handoff data; and communicating the MAP message from the mobile station to the second mobile switching control station.