PHS terminals on the move used to be prone to broken connections due to the lack of a handover function between Cell Stations (CSs) covered by different telephone exchanges. Handover was only available between CSs within the same exchange. This was regarded as the weak point of PHS, especially by drivers, in comparison with cellular phones which assure continuous communications while on the move.
Against this background, all three PHS operators have made handover available, even between different telephone exchanges, assuring continuous communications in cars and on foot.

In the diagram, handover was available from area A to A’, but not from area A’ to B which was covered by another telephone exchange. As most telephone exchanges in urban centers usually cover a radius of 2 to 3 kilometers, pedestrians with PHS terminals may lose their connection if they move to an area which is covered by another exchange. In addition, there is no way for users to know when they are moving to an area covered by another exchange.

Handover is made possible throughout areas A and B, assuring continuous communications between different telephone exchanges.
Improvement of the handover function has required the reprogramming of software installed in cell stations and different telephone exchanges. This upgrade began in February 1999 and is now almost complete. In most areas, PHS users on the move can now enjoy uninterrupted communications.

This improvement to the handover function is anticipated to make users more aware of PHS’s speech quality and high-speed data transmission capability, expanding the PHS market.