| 摘要 |
PURPOSE:To prevent the lowering of a service caused by increasing the time for securing a circuit by dispersing the calling quantity of a terminal into plural frequencies, and decreasing a collision. CONSTITUTION:Two or more incoming communication frequencies for control are provided in advance. In this state, an arbitrary incoming frequency is selected dynamically from them and set at every terminals 120-124, and always monitored simultaneously by a central equipment 101 having a storage part 104 which can store temporarily the control signals of all these incoming control frequencies. Accordingly, the calling quantity can be dispersed into plural frequencies, and the collision can be decreased. In such a manner, even if the number of terminals is increased, and the whole calling quantity is increased, the smooth communication service can be offered without increasing the time for securing a circuit. |
