Electronic Switching Is 'In'.

Electronic switching was one of the ten tremendous developments of Communications News' first decade and the promise of electronic switching has been fulfilled during the past decade as the pushbutton telephone, the digital PBX, and digital facsimile and high-speed data transmission over telephone

During CN's very first year the first electronic switching office went into commercial service at Succasunna, New Jersey, on May 30, 1965, and "Number One ESS" proved to be a pivotal point in telephone switching history.

That event was the result of a formal Bell Laboratories' effort begun at the end of World War II. The goal was to apply electronics to switching, and bring customers the speed, flexibility, and reliability offered by electronic components. Laboratory domonstration systems developed by the late 1940s relied on electronic tubes for logic, memory, and control functions. These systems greatly encouraged Bell engineers, but also pointed up the need for more economical logic and memory devices. The solid-state revolution, sparked by Bell Labs' invention of the transistor (see story, page 84), provided the breakthrough switching engineers needed. Developments then came rapidly, but the concept had to be tested and retested many times to make sure the new switching systems would meet the service standards Bell subscribers had come to expect. A customer trial from 1960 to 1962 in Morris, Illinois, proved electronic systems could do the job. The system used in Morris contained about 4,000 electronic tubes, and 12,000 transistors.

Two basic types of ESS were developed: the two-wire office used for commercial Bell system service, and the four-wire office used for the government's AUTOVON network. The first ESS in the AUTOVON network began operation in May 1966.

In the early 1960s GTE Automatic Electric was also active on the electronic switching front. A test model of its "Number One EAX" (Electronic Automatic Exchange) was operational in 1962. An initial installation of EAX equipment with a capacity of 600 lines was installed in the Portage, Indiana, exchange of General Telephone Company of Indiana, beginning in 1963, for a field trial.

GTE Automatic's Number One EAX was a common control telephone switching system that met the requirements for a medium to large and office and a combined end and toll office. Switching was accomplished by means of a 2-wire, space-divided, read network, driven by a stored program, with electronic common control.