Handover method for radiotelephone networks

Claim 1

A handover method for a cellular radiotelephone network for handing over a radiotelephone call established with a mobile via a first transceiver of a first cell to a second transceiver of a second cell accessing the mobile, said method comprising the steps of handing over the call at a handover level via a handover branch to said second transceiver in response to a handover instruction, with said handover step interrupting the call during a relatively short interruption time interval, and switching in the mobile from said first transceiver to said second transceiver in response to a switching instruction, said switching step interrupting the call during a relatively long predefined cut-off time interval and said handover branch being prepared before executing the handover and switching operations by reserving said handover branch, without the latter being connected to the call in progress, said method further comprising transmitting said switching instruction initiating the switching operation to the mobile and controlling timing of the handover to the handover branch in response to the handover instruction relative to said switching step so that said relatively short interruption time interval occurs during said predefined cut-off time interval.