US 7,096,020 B2 · System and method for implementing a handoff using a multiparty service in a mobile communication system

Abstract

A handoff system and method using an MPTY (multiparty) service in a mobile communication system. When a terminal senses that it is located at the boundary of a WCDMA during a WCDMA communication service, it transitions to a first state. In the first state, the terminal requests an MPTY service to a BS in a CDMA network. If the strength of a first current WCDMA signal is less than a predetermined first threshold, the terminal transitions to a second state. In the second state, the terminal requests an available MPTY call to be maintained. If the strength of a second current WCDMA signal is less than a predetermined second threshold, the terminal transitions to a third state. Then the terminal establishes a CDMA call using the maintained MPTY call in the third state. If the strength of a third current WCDMA signal is less than a predetermined third threshold, the terminal ends the WCDAM call.

Claims9

Dependent claims

A method of implementing a handoff using a multiparty (MPTY) service from a first base station (BS) that provides a communication service in a first communication scheme to a second BS that provides a communication service in a second communication scheme different from the first communication scheme in a mobile communication system, the method comprising the steps of:

upon sensing a handoff to the second BS, asking a visitor location register (VLR) connected to the second BS for an availability of an MPTY call through a home location register (HLR) connected to the first BS by a mobile station (MS);
notifying the MS of the availability of the MPTY call through the HLR if the MPTY call is available, and ordering a mobile switching center (MSC) that is connected to the VLR to activate the MPTY call by the VLR;
requesting the MSC to maintain one of active MPTY calls by the MS when the MS senses the availability of the MPTY call and transitions to a second state;
maintaining the active MPTY call to be assigned to the MS by the MSC;
and
establishing a call in the second communication scheme using the maintained MPTY call through the HLR when the MS transitions to a third state and ending a call in the first communication scheme by the MS.

3 more elements

A method of implementing in a mobile station (MS) a handoff using a multiparty (MPTY) service from a first base station (BS) that provides a communication service in a first communication scheme to a second BS that provides a communication service in a second communication scheme, which is different from the first communication scheme, in a mobile communication system, the method comprising the steps of:

transitioning to a first state to start the communication service in the second communication scheme when the MS senses that the MS is located at a boundary of a network that services in the first communication scheme during the communication service in the first communication scheme;
requesting the MPTY service to the second BS in the first state and, if the strength of a first current signal received in the first communication scheme is less than a predetermined first threshold, transitioning to a second state;
requesting an available MPTY call to be maintained in the second state and, if the strength of a second current signal received in the first communication scheme is less than a predetermined second threshold, transitioning to a third state;
and
connecting the MPTY service for maintaining a call in the first communication scheme and a call in the second communication scheme by establishing the call in the second communication scheme using the maintained MPTY call in the third state, and if the strength of a third current signal received in the first communication scheme is less than a predetermined third threshold, ending the call in the first communication scheme.

2 more elements

Dependencies are inferred from the claim text.

System and method for implementing a handoff using a multiparty service in a mobile communication system

Life of this patent

System and method for implementing a handoff using a multiparty service in a mobile communication system

Life of this patent

Abstract

Claims9