Virtual gateway node for dual-mode wireless phones
First Claim
1. A method of handing off a call at a dual-mode subscriber device from a wireless local area network to a wireless communication system comprising:
- creating, at a virtual gateway, a message in a first control signaling format initiating a call from an IP-based telephone switch to the dual-mode subscriber device via the wireless communication system;
receiving, at the dual-mode subscriber device, the call from the wireless communication system;
switching, at the dual-mode subscriber device, the call from the wireless local area network to the connection to the wireless communication system;
performing, at the dual-mode subscriber device, at least one of (1) transmitting a WLAN-based handoff instruction to the virtual gateway and (2) receiving a WLAN-based handoff instruction from the virtual gateway;
creating and sending, at the virtual gateway, a registration message to the IP-based telephone switch; and
receiving, at the dual-mode subscriber device, a call confirmation message from the virtual gateway via the wireless local area network, wherein the call confirmation message originated at the IP-based telephone switch.
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Accused Products
Abstract
The invention is a virtual gateway that mediates between a dual-mode subscriber device and an IP-based PBX. In particular, the virtual gateway includes a WLAN interface for communicating with the dual-mode subscriber device and a network interface (wired or wireless) for communicating with the IP-based PBX over the Internet. As such, the virtual gateway may relay voice and call control instructions between the dual-mode subscriber device and the IP-based PBX, and may provide the same call control functions to the dual-mode subscriber device provided by the call control processor in existing dual-mode phones. The invention further provides a dual-mode subscriber device suitable for operation with the virtual gateway. Because the dual-mode subscriber device does not require a call control processor, the battery life and cost of the device are significantly improved.
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Citations
47 Claims
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1. A method of handing off a call at a dual-mode subscriber device from a wireless local area network to a wireless communication system comprising:
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creating, at a virtual gateway, a message in a first control signaling format initiating a call from an IP-based telephone switch to the dual-mode subscriber device via the wireless communication system; receiving, at the dual-mode subscriber device, the call from the wireless communication system; switching, at the dual-mode subscriber device, the call from the wireless local area network to the connection to the wireless communication system; performing, at the dual-mode subscriber device, at least one of (1) transmitting a WLAN-based handoff instruction to the virtual gateway and (2) receiving a WLAN-based handoff instruction from the virtual gateway; creating and sending, at the virtual gateway, a registration message to the IP-based telephone switch; and receiving, at the dual-mode subscriber device, a call confirmation message from the virtual gateway via the wireless local area network, wherein the call confirmation message originated at the IP-based telephone switch. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A dual-mode wireless communication device suitable for operation in a WLAN-based system including a wireless local area network, a virtual gateway and an IP-based telephone switch as well as in a wireless communication system, comprising:
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a VoIP processing module configured to establish a WLAN-based call with the IP-based telephone switch via the virtual gateway; a cellular processing module configured to establish a PSTN call with the wireless communication system while a call is in progress with the IP-based telephone switch via the WLAN and the virtual gateway, wherein the PSTN call is initiated from the IP-based telephone switch in response to receiving a message from the virtual gateway in a first control signaling format; and a controller module configured to switch between the WLAN-based call with the IP-based telephone switch via the virtual gateway and the PSTN call with the wireless communication system, wherein; the VoIP processing module is configured to at least one of (1) transmit a WLAN-based handoff instruction to the virtual gateway and (2) receive a WLAN-based handoff instruction from the virtual gateway; the virtual gateway creates and sends a registration message to the IP-based telephone switch; and the VoIP processing module is further configured to receive a call confirmation message from the virtual gateway via the wireless local area network, wherein the call confirmation message originates at the IP-based telephone switch. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 44, 45)
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27. A method of establishing a telephone connection at a dual-mode wireless communication device suitable for operation in (1) a WLAN-based system including a wireless local area network, a virtual gateway and an IP-based telephone switch as well as in (2) a wireless communication system, comprising the steps of:
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establishing, at the dual-mode wireless communication device, a WLAN-based call with the IP-based telephone switch via the virtual gateway; establishing, at the dual-mode wireless communication device, a cellular-based call with the wireless communication system after the WLAN-based call with the IP-based telephone switch via the virtual gateway is in progress, wherein the cellular-based call is initiated from the IP-based telephone switch in response to receiving a message from the virtual gateway in a first control signaling format; switching, at the dual-mode wireless communication device, between the WLAN-based call established with the IP-based telephone switch via the virtual gateway and the cellular-based call with the wireless communication system; performing, at the dual-mode wireless communication device, at least one of (1) transmitting a WLAN-based handoff instruction to the virtual gateway and (2) receiving a WLAN-based handoff instruction from the virtual gateway; creating and sending, at the virtual gateway, a registration message to the IP-based telephone switch; and receiving, at the dual-mode wireless communication device, a call confirmation message from the virtual gateway via the wireless local area network, wherein the call confirmation message originates at the IP-based telephone switch. - View Dependent Claims (28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 46, 47)
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Specification