Patent ID: 6424639
Filing Date: 2002-07-23
Classification: H04L,H04W,Y02D

Abstract:
A method comprising:establishing a mobile packet network call over a transmission link, said transmission link extending between a mobile terminal device and a given interworking function and connecting said mobile terminal device to a wireless communication device over a first interface and further connecting said wireless communication device to said given interworking function over a second interface via a wireless link to a base station, said given interworking function changing from a first interworking function to a second interworking function, said transmission link comprising a traffic channel, a data link layer link, and a network layer link, said transmission link comprising a packet mode in which said traffic channel is up and a dormant mode in which said traffic channel is down while said data link layer link and said network layer link are maintained; providing to said wireless communication device network region identifier information when said transmission link is in said dormant mode; said wireless communication device determining when said given interworking function has changed from said first interworking function to said second interworking function by determining when there is a corresponding change in network region identifier information; said wireless communication device initiating a link control protocol negotiation with said mobile terminal device when said corresponding change in said network region identifier information has been determined; said mobile terminal device responding to said initiation of said link control protocol negotiation by forwarding link control protocol packets to said second interworking function via said wireless communication device, causing said transmission link to enter said packet mode and to bring up said traffic channel, said mobile terminal device then establishing a data link layer link with said second interworking function; after said data link layer link with said second interworking function is established, said mobile terminal device and said second interworking function negotiating network control protocol options and establishing a network layer link between said mobile terminal device and said second interworking function.