Cell handover

A smart card for use in a mobile station for a cellular telecommunications system wherein a handover can be made between cells of different networks during a call, the smart card including data for controlling whether the mobile station is permitted to utilise the handover to continue the call.

A cellular mobile telecommunications device comprising:

• telecommunications circuitry for establishing a call with different cellular networks;
• processing circuitry configured to make a cell handover between cells of different networks during a call;
• and circuitry operable as a default behavior to carry out a location update with the network to which the handover was made upon termination of the call except under predetermined circumstances, said predetermined circumstances including at least one of (a) a situation where the network from which the handover was made is the HPLMN, in which case a HPLMN search is carried out upon termination of the call (b) a situation in which the device has been provided with data corresponding to a behavior to be followed after the end of the call, in which case the behavior is carried out upon termination of the call, and (c) the network to which the handover is to be made is on a forbidden list to which a handover is not permitted.