Method and apparatus for performing handover of an emergency call between wireless networks

An apparatus for wireless communication, comprising:

• means for communicating with a packet-switched wireless network by a user equipment (UE) for an emergency call;
• means for receiving an indication to perform handover from the packet-switched wireless network to a circuit-switched wireless network;
• means for sending a message from the UE comprising an emergency indication to initiate handover to the circuit-switched wireless network, the emergency indication comprising a preconfigured called party number,
• wherein an Emergency Session Transfer Number for single radio voice call continuity (SRVCC) (E-STN-SR) for the emergency call of the UE is sent by a Mobile Positioning Center (MPC) to a Mobile Switching Center (MSC) of the circuit-switched wireless network in response to a query from the MSC;
• means for communicating with the circuit-switched wireless network for the emergency call after handover;
• means for obtaining location services via the packet-switched wireless network for the emergency call prior to handover;
• and
• means for obtaining location services via the circuit-switched wireless network for the emergency call after handover.

A computer program product, comprising:

• a non-transitory computer-readable medium comprising:
• code to cause at least one computer to communicate with a packet-switched wireless network by a user equipment (UE) for an emergency call;
• code to cause the at least one computer to receive an indication to perform handover from the packet-switched wireless network to a circuit-switched wireless network;
• code to cause the at least one computer to send a message comprising an emergency indication to initiate handover to the circuit-switched wireless network, the emergency indication comprising a preconfigured called party number,
• wherein an Emergency Session Transfer Number for single radio voice call continuity (SRVCC) (E-STN-SR) for the emergency call of the UE is sent by a Mobile Positioning Center (MPC) to a Mobile Switching Center (MSC) of the circuit-switched wireless network in response to a query from the MSC;
• code to cause the at least one computer to communicate with the circuit-switched wireless network for the emergency call after handover;
• code to cause the at least one computer to obtain location services via the packet-switched wireless network for the emergency call prior to handover;
• and
• code to cause the at least one computer to obtain location services via the circuit-switched wireless network for the emergency call after handover.

A method of supporting wireless communication, comprising:

• receiving at a network entity a first message sent by a user equipment (UE) to initiate handover of an emergency call from a packet-switched wireless network to a circuit-switched wireless network;
• recognizing the emergency call based on an emergency indication included in the first message;
• determining a designated number for the emergency call from a location server;
• replacing the emergency indication in the first message with the designated number for the emergency call to obtain a second message;
• sending the second message from the network entity to a Mobile Switching Center (MSC) of the circuit-switched wireless network for call origination for handover of the emergency call,
• wherein an Emergency Session Transfer Number for single radio voice call continuity (SRVCC) (E-STN-SR) for the emergency call of the UE is sent by a Mobile Positioning Center (MPC) to the MSC in response to a query from the MSC;
• and
• sending an identity of a target serving node in the circuit-switched wireless network to the location server to support location services for the UE in the circuit-switched wireless network after handover and during at least the emergency call to maintain location continuity.

An apparatus for wireless communication, comprising:

• means for receiving at a network entity a first message sent by a user equipment (UE) to initiate handover of an emergency call from a packet-switched wireless network to a circuit-switched wireless network;
• means for recognizing the emergency call based on an emergency indication included in the first message;
• means for determining a designated number for the emergency call from a location server;
• means for replacing the emergency indication in the first message with the designated number for the emergency call to obtain a second message;
• means for sending the second message from the network entity to a Mobile Switching Center (MSC) of the circuit-switched wireless network for call origination for handover of the emergency call,
• wherein an Emergency Session Transfer Number for single radio voice call continuity (SRVCC) (E-STN-SR) for the emergency call of the UE is sent by a Mobile Positioning Center (MPC) to the MSC in response to a query from the MSC;
• and
• means for sending an identity of a target serving node in the circuit-switched wireless network to the location server to support location services for the UE in the circuit-switched wireless network after handover and during at least the emergency call to maintain location continuity.

A method of supporting wireless communication, comprising:

• determining an Emergency Session Transfer Number for single radio voice call continuity (SRVCC) (E-STN-SR) for an emergency call for a user equipment (UE) at a network entity;
• receiving a query for the UE at the network entity, the query being sent by a Mobile Switching Center (MSC) of a circuit-switched wireless network in response to handover of the emergency call from a packet-switched-wireless network to the circuit-switched wireless network;
• sending, by a Mobile Positioning Center (MPC), the E-STN-SR for the emergency call for the UE from the network entity to the MSC in response to the query, the E-STN-SR being used to route the emergency call to a network server anchoring the emergency call;
• and
• sending an identity of a target serving node in the circuit-switched wireless network to the location server to support location services for the UE in the circuit-switched wireless network after handover and during at least the emergency call to maintain location continuity.

An apparatus for supporting wireless communication, comprising:

• means for determining an Emergency Session Transfer Number for single radio voice call continuity (SRVCC) (E-STN-SR) for an emergency call for a user equipment (UE) at a network entity;
• means for receiving a query for the UE at the network entity, the query being sent by a Mobile Switching Center (MSC) of a circuit-switched wireless network in response to handover of the emergency call from a packet-switched wireless network to the circuit-switched wireless network;
• sending, by a Mobile Positioning Center (MPC), the E-STN-SR for the emergency call for the UE from the network entity to the MSC in response to the query, the E-STN-SR being used to route the emergency call to a network server anchoring the emergency call;
• and
• means for sending an identity of a target serving node in the circuit-switched wireless network to the location server to support location services for the UE in the circuit-switched wireless network after handover and during at least the emergency call to maintain location continuity.