METHOD AND APPARATUS FOR EFFECTING HANDOFF BETWEEN DIFFERENT CELLULAR COMMUNICATIONS SYSTEMS
First Claim
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;
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.
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Accused Products
Abstract
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, different cellular system controlled by a second mobile switching control station is described. The method comprises measuring at the mobile station a parameter of a signal transmitted by said first base station and a parameter of a signal transmitted by said second base station. When the parameters reach a predetermined condition, a signal quality message is communicated from the mobile station via the first base station to said first mobile switching control station, which responds by generating information for a channel request message for the second mobile switching control station and transmitting the same to the mobile station. The mobile station generates from the information a channel request message for the second mobile switching control station and transmits the same to the second mobile switching control station. The second mobile switching control station generates channel information identifying a channel in the second communications system for the mobile station so that the handoff may be effected.
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Citations
30 Claims
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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:
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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; 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. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A mobile station comprising:
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a first transceiver chain operable to receive and transmit signals with a first base station in a first cellular communications system, said first cellular communications system being a CDMA system; a second transceiver chain operable to receive and transmit signals with a second base station in a second cellular communications system, said second cellular communications system being a GSM system; and a controller for; measuring a first parameter of a first signal transmitted by said first base station; measuring a second parameter of a second signal transmitted by said second base station; communicating a signal quality message from the mobile station via the first base station to said first cellular communications system, when the first and second parameters reach a predetermined condition; receiving from the first base 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; generating a Mobile Application Protocol (MAP) message containing the handoff data; and communicating the MAP message to the second base station. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15, 16)
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17. An apparatus for 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:
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means for measuring at the mobile station a first parameter of a first signal transmitted by said first base station; means for measuring at the mobile station a second parameter of a second signal transmitted by said second base station; means for communicating a signal quality message from the mobile station through the first base station to said first mobile switching control station, when the first and second parameters reach a predetermined condition; means for 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; means for communicating the ADDS message from said first mobile switching control station to said mobile station; means for generating at the mobile station a Mobile Application Protocol (MAP) message containing the handoff data; and means for communicating the MAP message from the mobile station to the second mobile switching control station. - View Dependent Claims (18, 19, 20, 21, 22, 23)
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24. A computer program product comprising a computer readable medium for 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 computer readable medium further comprising:
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code for causing a computer to measure at the mobile station a first parameter of a first signal transmitted by said first base station; code for causing a computer to measure at the mobile station a second parameter of a second signal transmitted by said second base station; code for causing a computer to communicate 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; code for causing a computer to generate 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; code for causing a computer to communicate the ADDS message from said first mobile switching control station to said mobile station; code for causing a computer to generate at the mobile station a Mobile Application Protocol (MAP) message containing the handoff data; and code for causing a computer to communicate the MAP message from the mobile station to the second mobile switching control station. - View Dependent Claims (25, 26, 27, 28, 29, 30)
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Specification