Dynamic micro-cell assignment technique with distributed control scheme

The Personal Handy Phone System (PHS) employs autonomous distributed control and a dynamic channel allocation scheme. A base station does not have many traffic channels because its cell radius is only a few hundred meters. However, a base station can experience heavy traffic. In this case, the blocking probability will increase. Congestion control can be employed, but it can never solve this problem fundamentally. We propose a dynamic cell assignment scheme and evaluate the improvement in system performance by computer simulations and theoretically. The scheme overlaps the base stations in and adjacent to heavy traffic areas to equalize base station loading. Each base station broadcasts a congestion factor and each mobile station dynamically selects a base station to get a traffic channel. This dynamic cell assignment technique makes it possible to improve the blocking probability characteristics