Dial Digit Capture Algorithm for a Telephone Billing System
Original Publication Date: 1987-Sep-01
Included in the Prior Art Database: 2005-Feb-01
This invention is part of an electronic exchange telephone billing system. The purpose of the billing system is to monitor all outgoing subscriber telephone calls to 1) identify any one of 40,000 subscribers making a call, 2) record the digits dialed by the caller, 3) determine call initiation time, duration of call, and call disconnect time, and 4) properly itemize and bill the effective calls in realtime. The system is a distributed, modular, electronic telephone exchange which includes multiple main control units (MCUs) operating in load sharing mode. Each MCU can handle up to 36 new calls simultaneously. The processing of a new call includes 1) the detection of caller off-hook, 2) register assignment, 3) collection at the register of digits dialed by the calling subscriber, and 4) dial location of the register.