Method and system for vertical handoff with target traffic channel setup conveyed via source channel

摘要

A method and system for vertical handoff of a mobile station from a first-protocol RAN to a second-protocol RAN. The method and system provide a make-before-break vertical handoff, by having the first-protocol RAN (i) acquire, on behalf of the mobile station, a traffic channel assignment defining one or more traffic channel parameters for air interface communication in the second-protocol RAN, and (ii) pass to the mobile station, via the first air interface protocol, the one or more traffic channel parameters so that the mobile station can then readily switch over to communication under the second-protocol RAN. Optimally, the acquisition and passing of the one or more second-protocol traffic channel parameters may occur without the mobile station having requested the handoff, without the mobile station having asked for the traffic channel assignment, and without the mobile station having yet begun communication with the second-protocol RAN.

主权项

1. A method operable in a wireless communication system having a plurality of radio access networks (“RANs”) serving air interface traffic channels defined by disparate air interface protocols, including a first RAN serving air interface traffic channels according to a first air interface protocol (“first protocol traffic channels”) and a second RAN serving air interface traffic channels according to a second air interface protocol (“second protocol traffic channels”), the method comprising:
while a mobile station has a first protocol traffic channel served by the first RAN, the first RAN detecting a handoff trigger for handoff of the mobile station to the second RAN and responsively (i) requesting the second RAN to assign a second protocol traffic channel for the mobile station, (ii) receiving from the second RAN one or more parameters defining the second protocol traffic channel assigned by the second RAN for the mobile station, and (iii) transmitting to the mobile station via the first protocol traffic channel the one or more parameters without the mobile station having requested assignment of the second protocol traffic channel and without the mobile station having searched for coverage under the second air interface protocol to trigger the handoff, whereby the one or more parameters are usable by the mobile station to readily switch over from communication on the first protocol traffic channel to communication on the second protocol traffic channel.