| 摘要 |
PURPOSE:To allow an extension subscriber to recognize the degree of charging during talking by transmitting an interruption tone to the extension subscriber during talking through a trunk line at each charging unit time. CONSTITUTION:When an extension subscriber STA makes a call through a trunk line, the call is connected to an outgoing register 2 through a channel switch SW. The number information of a called party dialed by the extension subscriber STA is identified by the outgoing register 2 and stored in a storage device 3. A central controller 1 receives the information of the storage device 3 and transmits it to a unit time identification device 4. The unit time identification device 4 analyzes this information and calculates the charging unit time at the calling zone. The charging unit time information is transmitted to the central controller 1. The central controller 1 connects an interruption tone transmitter 5 to a channel of a channel switch SW and transmits an interruption tone to an interruption tone transmitter 5 at each unit time by using the information calculated by the unit time identification device 4. |
