Patent ID: 7089008
Filing Date: 2006-08-08
Classification: H04W

Abstract:
1. A method for performing an inter-system handover of a user terminal in a telecommunications network comprising a first telecommunications system operable according to a first protocol and comprising a first service subsystem and a first access subsystem and a second telecommunication system operable according to a second protocol and comprising a second service subsystem and a second access subsystem; the user terminal storing capability data indicative of a capability of the user terminal to communicate with the service subsystems and the access subsystems; the method comprising the steps of: transmitting initial capability data indicative of the capability of the user terminal to communicate with the first service subsystem and one of the first and second access subsystems from the user terminal to one of the first and second access subsystems; transmitting the initial capability data that is indicative of the capability of the user terminal to communicate with the first service subsystem from one of the first and second access subsystems to the first service subsystem; establishing a connection between the user terminal and the first service subsystem via one of the first and second access subsystems by means of the initial capability data; determining that a handover of the connection is to be performed from the first service subsystem to the second service subsystem or from one of the first and second access subsystems to the other of the first and second access subsystems; transmitting from the user terminal to the network further capability data indicative of the capability of the user terminal to communicate with the second service subsystem or the other of the first and second access subsystems; and handing over the connection via the further capability data.