Personal handy phone system portable station design for hand-over operation

In the Personal Handy Phone System, the channel must be handed over from one zone to another zone at the Portable Station. This involves two important processes: detecting that the channel has moved outside of the communication zone and determining the new zone. This article describes these two processes. The channel is determined to be outside the zone from the change in communication quality. The result of this evaluation depends on the algorithm used and the duration. The second process compares the reception levels of all the base station control channels that the portable station receives within a pre-defined period and then selects the appropriate base station