| 摘要 |
PURPOSE:To reduce the number of operating frequencies and to utilize the notice frequency effectively by adopting the intermittent system sending a notice signal on request from a portable telephone set. CONSTITUTION:When a call takes place, the control setting a radio line between a portable telephone set and a stationary radio station is applied at first, and it is required for the stationary radio equipment to always grasp portable telephone sets resident in its own service zone. As to the notice mode of the stationary radio station, a signal is sent intermittently for 10min at, e.g. an interval of 4sec+ or -alpha deg. in, e.g. in incoming control channel. While a portable telephone set is resident in its own service zone, it is required to give notice (transmission of control signal) and when it is discriminated that no portable telephone set is resident in the zone, the notice is stopped. Thus, number of traffics of the radio frequency is reduced to reduce the collision, the transmission of the notice signal is attained in the same frequency in other service area and the changeover of the notice channel is evaded and the effective utilization of the operating frequency is attained. |
