Voice call continuity application server between IP-CAN and CS networks
First Claim
Patent Images
1. A communication system, comprising:
- a first access network;
a media gateway; and
a first node adapted to change at least one bearer between a user equipment and the media gateway, while maintaining an uninterrupted bearer between the media gateway and a source/destination node.
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Accused Products
Abstract
A system and method for continuous voice calls when a user switches between packet data and circuit switched access networks. In one example embodiment, the present innovations include an interworking system that supports voice call continuity for a user that moves between IP-CAN and CS networks (e.g., PSTN or GSM). In one example embodiment, the present innovations comprise a voice call continuity application server (VCC-AS) that serves as an anchor point for a voice call (i.e., it is the node from which a handover is initiated) and controls and handles voice calls to and from the user equipment (UE) regardless of the access network.
258 Citations
21 Claims
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1. A communication system, comprising:
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a first access network;
a media gateway; and
a first node adapted to change at least one bearer between a user equipment and the media gateway, while maintaining an uninterrupted bearer between the media gateway and a source/destination node. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method of handing off a wireless voice call between a packet data network and a circuit switched network, comprising the steps of:
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establishing one or more first call control legs between a user equipment and a first node;
establishing one or more second call control legs between the first node and a destination;
when the user equipment moves from a first access network to a second access network, establishing one or more third call control legs between the user equipment and the first node via the second access network, and;
optionally terminating the one or more first call control legs via the first access network, if desired. wherein the one or more third call legs use a different bearer than the one or more first call legs; and
wherein SIP is used as a call control signaling for first, second, and third call control legs. - View Dependent Claims (11, 12, 13, 14, 15)
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16. A method of maintaining a voice call when a user equipment changes access networks, comprising the steps of:
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registering a user equipment to a first node using access technology associated with either a first packet data access network or second circuit switched access network;
handling user equipment originating calls, initiated in a first packet data access network, by terminating SIP signaling from the user equipment and initiating another call control signaling leg toward a destination;
handling user equipment originating calls, initiated in a second circuit switched access network, by instructing the user equipment to create a circuit switched bearer associated with the second circuit switched access network, terminating SIP signaling from the user equipment, and initiating another call control signaling leg toward the destination;
handling user equipment terminating calls, in the first packet data access network, by terminating an incoming call control signaling leg and initiating SIP signaling toward the user equipment; and
handling user equipment terminating calls, in the second circuit switched access network, by terminating the incoming call control signaling, instructing at least the user equipment to create a circuit switched bearer associated with the second circuit switched access network for circuit switched call leg, and initiating SIP signaling toward the user equipment. - View Dependent Claims (17, 18, 19, 20)
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21-24. -24. (canceled)
Specification