Cellular communication system handover

摘要

A portable terminal of a cellular communication system is provided with apparatus for initiating a handover procedure to handover a connection established with one radio termination of a fixed system to another radio termination of the fixed system. The apparatus continually monitors system communication channels for transmissions by the radio terminations received at the portable terminal and identifies the nearest radio termination to be the one from which signals are received with the highest radio signal strength. If a connection is initially established by the mobile terminal with a first radio termination, but the mobile terminal subsequently moves away from that radio termination, the apparatus initiates a handover attempt of the connection to the radio termination from which transmissions are now received with the highest radio signal strength. Normally signals received with the highest signal strength will originate from the closest fixed radio termination. The initiation attempt is made on the basis that there is another radio termination present that will provide a higher radio signal strength even if the existing connection is determined to be of good quality and for which transmissions are being received with a signal strength that is classed as good or satisfactory. Such a pre-emptive handover can avoid the possible degradation in communication channel quality that can occur by the time a normal handover operation is completed.