| 摘要 |
PURPOSE:To dynamically add communication channels to temporary lack for respective areas by providing radio units which attains transmission and reception for respective base stations in correspondence with a frequency which a central exchange instructs for respective calls. CONSTITUTION:Respective radio areas a1-a7 have fixed channels f1-f7 corresponding to respective average traffic and the frequency groups are fixed lest they interface each other. The central exchange 1 simultaneously allocates the communication frequencies lest they are overlapped in respective areas for preventing mutual interference between adjacent areas whenever a call is made to a connected moving terminal or whenever the call is made from the moving terminal at the time of allocating the communication channel. In an area a1, for example, C-number of radio units are given apart from the radio units (n-number) for the fixed channels. When there is a communication request for over-flowing n-number of channels, the exchange 1 allocates the frequency which is not used at present in an additional communication channel f0 and at the same time, the frequency is instructed. The signalled radio unit is tuned and it operates. |
