SYSTEM FOR TRANSMITTING TALKING ELAPSED TIME FORECAST TONE

摘要

PURPOSE:To inform a talking time relating to a charge to a subscriber by providing a means transmitting a forecast tone to a subscriber at a prescribed interval before addition of a talking charge and a means changing the intermitting number and frequency of the said forecast tone in response to the talking elapsed time. CONSTITUTION:A forecast tone transmission controller 12 receiving a forecast tone transmission order every time a specified time is elapsed after start of charging controls a frequency selecting device 8 and an intermission number selector 10 to designate the frequency of the forecast tone and the intermission number in response to the order reception circuit and transmits a selected notice tone to a calling subscriber A. When the charging system is 3min-1min rate, the forecast tone transmitted to the subscriber undergoes selection of frequency and number of times in response to the section of a time N when the talking time is Nmin. The frequencies F1, F2, F3 are selected as F1F2F3.