GB1423946A - Telephone metering costs - Google Patents

Abstract

1423946 Metering pay-stations STANDARD TELEPHONES & CABLES Ltd 4 April 1974 14981/74 Heading H4K In a metering control arrangement for paystations, receipt of a first metering pulse causes first timing pulses to step a counter. If a second metering pulse is received before the counter reaches a predetermined stage thereby indicating a high rate trunk call the counter is "frozen" to indicate the charging rate for the call. The counter is coupled to a read only memory which also has an input from a credit meter and an output of the memory is marked when the caller's credit falls below a predetermined minimum # 0 to cause a pay-tone to be sent to the caller, such an arrangement provides a reasonable period of time for a caller to insert more money before his credit falls below zero e.g. where metering pulses arrive at rates greater than about 1 per 4À5 seconds. If the counter reaches 14 before a second metering pulse arrives the counter is reset and caused to count local timing pulses which occur at a rate of, e.g. 1 per 30 sees. as opposed to a rate of 2 per second for the first timing pulses. If a second metering pulse arrives before the 11th local timing pulse a low rate trunk call is identified and pay-tone is sent to the caller when the credit meter reads zero. In both the above eases, the received metering pulses apparently decrement the credit meter, although this is not stated. If a second metering pulse is not received, the counter resets on every 10th count and also causes the credit meter to decrement by one unit. Pay tone is sent when the credit meter falls to zero.