Transitioning of a packet-switched emergency call between first and second types of wireless access networks

摘要

A mobile station that is initially attached to a first type of wireless access network is involved in a packet-switched emergency call. Upon detection of transitioning of the mobile station, a message is sent indicating transitioning of the mobile station from the first type wireless access network to the second type wireless access network to cause the packet-switched emergency call to be performed over the second type wireless access network.

主权项

1. A method comprising:
pre-registering, by one or more processors, a mobile station with a second type wireless access network when the mobile station is initially attached to a first type wireless access network; storing information relating to a predefined emergency call session to be used with the second type wireless access network; detecting, by one or more processors, that the mobile station is involved in a packet-switched emergency call while the mobile station is attached to the first type of wireless access network; detecting, by the one or more processors, transitioning of the mobile station from the first type wireless access network to the second type wireless access network; and in response to detecting transitioning of the mobile station, the one or more processors sending a message indicating transitioning of the mobile station from the first type wireless access network to the second type wireless access network to cause the packet-switched emergency call to be performed over the second type wireless access network using the information of the predefined emergency call session to avoid negotiating a context of a packet-switched emergency call with the second type wireless access network after the transitioning, the first type wireless access network being an Evolved Universal Terrestrial Radio Access (EUTRA) network and the second type wireless access network being a High Rate Packet Data (HRPD) access network.