TELECOM Digest OnLine - Sorted: Re: Non-Bell ESS

Re: Non-Bell ESS

Paul Coxwell (
Thu, 07 Jul 2005 00:25:40 +0100

> The Bell System put its first test call through a laboratory
> Electronic Switching System in 1958 and had a prototype system in
> public service in the early 1960s.

> Would anyone know when other telephone companies, either in the
> U.S. or abroad, developed and implemented their own ESS? For
> instance, when did Automatic Electric put one in service?

In Britain, the GPO trialed an electronic switch at Highgate Wood
using PAM/TDM (Pulse Amplitude Modulation/Time Division Multiplex)
around 1962. It was not entirely successful.

The first fully operational electronic switch went into service in
Ambergate, Derbyshire in 1966, and the GPO also claims this to be the
first electronic exchange in Europe. This switch was known as the
TXE2 (for Telephone eXchange Electronic), using common control with
reed relay switching points.

TXE2 was designed for smaller offices, generally up to a couple of
thousand lines. The later TXE4 switch intended for larger offices
didn't roll out until the mid-1970s.


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