Telephone Exchange – Telecommunications System
Telephone exchange is a telecommunications system used in the public switched telephone network or in large enterprises. An exchange consists of electronic components and in older systems also human operators that interconnect (switch) telephone subscriber lines or virtual circuits of digital systems to establish telephone calls between subscribers. A private telephone exchange is often referred to as a private branch exchange (PBX), when it has connections to the public switched telephone network.
When telephonic communication systems were first invented and few people actually owned a telephone with number buttons. Telephone calls would be connected via a human operator. You would lift a receiver, the switchboard operator would ask you for the number you wished to call and he or she would plug a wire into the requisite part of the board to have you connected.
However, as telephone became more popular, it became increasingly impractical to have humans connecting the calls by hand and so electromechanical switchboard were invented. Soon communications companies found that even this was not enough-there was so much telephonic traffic to ideal with that they started to overload and seize up.
It was Erna Schneider Hoover (Birth Year: 1926), a computer programmer with a PhD in mathematics and a specialist in symbolic logic who struck upon the solution when she created a computerized switching system that monitored the frequency of incoming telephone calls at various times and rearranged the call acceptance rate at peak times to prevent overloading. This software was patented in 1971 and is renowned for being one of the very first software patents ever issued.
Not only had a telecommunications pioneer, Dr. Hoover also successfully juggled her family life with a high-flying career. The story goes that she drew the very first sketches for the system when she was in hospital after having given birth to the first of her three children. It was the success of this software that led her to take up the first position as a female supervisor in a Bell Laboratories technical department.