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Canada and the Birth of the Digital World: The Contributions of R. Charles Terreault
By Jean-Guy Rens

Canada opened the way to the Digital World. This breakthrough took place on the technological plane, but one of the keys to success was managerial – with a zest of vision to set things going.

The principals of the Digital World were well known. AT&T had launched in 1936 the largest research program ever to explore the potential of electronic technology, both in transmission and switching.

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Jean-Guy RensThe invention of the transistor was one of the most famous offspring of this massive investment. The result had been the No. 1-ESS, a hybrid switch, put into service in 1965.1 The ESS was electronic in that its stored-programme control enabled management of the entire switch by a central memory. It was based on space-division in that calls were established by the connection of two physical elements. Each call transited through a separate circuit that was dedicated for the length of the call. It was a first step towards the Digital World, but it was not the Digital World.

Bell Canada and its subsidiary, Northern Electric (nowadays Nortel) followed the US example, and in 1971 started deploying their own hybrid system – the SP-1. Indeed, this was the first major technological achievement in the modern history of Canadian telecommunications. But such was the culture of innovation among Canadian engineers that by September, 1969, Northern Electric had undertaken a project unprecedented for a North American firm: to devise a twenty-year plan for developing a telecommunications network.

The director of the project was a young Bell Canada engineer, R. Charles Terreault. He quickly assembled a twenty-person team, including Jacques Deregnaucourt (from France) and Ivan Godier as senior researchers. The result of this effort was the monumental twelve-volume Long Term Network Evolution Study, which drew upon the latest developments in microelectronics. The plan forecast the total digitization of the network up to the point of ISDN, then called Multiple-Use Selective Routing. Everything was planned for, from decentralization of switching toward the user to an orientation toward broadband switching (for video). The cornerstone of Terreault's plan was the introduction of a complete line of digital switches by the late 1970s and early 1980s.i

Terreault had discovered digital switching in 1960–61 during a year of training at the École nationale supérieure des télécommunications in Paris. He visited Pierre Lucas and Louis-Joseph Libois's laboratory at CNET: "It was then that I had an intuitive idea of the potential of digital switching."ii When Bell put its first digital transmission system, the T-1, into service in 1965, Terreault realized that the digitization trend was irreversible, not only in transmission but in switching. In 1965–66, he went to the Bell Labs' famous seminar, where he met the telecommunications pioneers John Mayo, Fred Andrews, and H.S. McDonald, whose work had demonstrated the feasibility of digital switching.

Terreault symbolized the new generation of clear-minded Canadian researchers who had emerged since the severance of the umbilical cord that linked Northern Electric with Western Electric and its prestigious Bell Labs. He had acquired the intellectual capacity that would enable him and his talented Digital World team members to pioneer the digital revolution in Canada and throughout a good part of the world ... if he and his colleagues were able to convince Bell Canada's senior management.

The real issue was not simply technological, but encompassed all aspects of the strengths and capabilities of Bell Canada, Northern Electric and their new joint venture Bell-Northern Research (BNR). Recall that the SP-1 had only just been launched in Canada . Wasn't it better to amortize the investment made in the development of this hybrid system before starting another leap forward? Terreault performed a series of impact studies on a five years status quo. All indicators showed that a rapid transition to fully digital switching would be profitable for the carrier.

Then came Don Chisholm's intervention. President of BNR since its inception, he was a digital messiah and the understanding between him and Terreault was unsurpassed. Many executives at the companies were opposed not to the conclusions of the Long Term Network Evolution Study, but to the pace of the transition to the digitalization world.

Terreault's long-term plan was ultimately accepted. In 1972, Bell, Northern, and BNR undertook a joint brainstorming session on digital switching that resulted in the definition of three essential elements: a private switchboard (PBX), a low-capacity public switch, and a high-capacity public switch. One of the members of the SP-1 "super-team", Colin Beaumont, was heavily involved in the design of the PBX. This experience would provide the best training field for the birth of the future all-digital central office switching system — the DMS.

The PBX development programme began right away. In June, 1973, a codec was developed based on a single extremely integrated circuit, so that each telephone line was served by its own codec. This technical achievement was to be the key to all digital-switch programmes. It equipped Northern's first completely digital product, a PBX capable of serving organizations with from 100 to 7,600 inside lines. Called the SL-1, it was introduced in December, 1975. Its wide range was notable; thanks to the extreme flexibility of digital technology, it could serve most large or medium-sized companies, whereas in the past different models had to be manufactured to cover different needs.iii

But the true debate concerned the timing of the R&D programme for the low- and high-capacity digital switches anticipated in Terreault's development plan. At the time, the SP-1 had just begun to be marketed, and some felt that its R&D costs should be amortized first. A high-level ad-hoc committee was formed including Don Chisholm (Bell-Northern Research), Bill Anderson (Bell's vice-president, engineering), and Lloyd Webster (Northern's vice-president, technology). Its mission was to establish a consensus in favour of digital, and it managed more or less to quiet the loudest opposition.

"D-Day" for the R&D policy committee was March 6, 1975. A presentation was made to the Tricorporate Policy Coordinating Committee (its members were BNR, Northern Telecom, and Bell Canada). The meeting took place at Bell's Montreal head office and brought together the presidents and executive vice-presidents of all three companies. Robert Scrivener represented Bell; John Lobb was there for Northern (at that time renamed Northern Telecom); and Don Chisholm for BNR. Anderson, Webster, and Terreault made presentations from the respective points of view of the carrier, the manufacturer, and the researcher. They made their point, and a budget of $140 million over five years was devoted to developing a complete line of digital switches. The Digital Multiplex System was conceived.

In 1976, there were a number of serious competitors in France and the United States driving toward digital technology, and announcements succeeded each other with great regularity. AT&T, GTE, and Vidar were all working on isolated long-distance systems, while CNET and Stromberg-Carlson were working on local ones. Unlike those of its competitors, Northern Telecom's project involved a complete range of local and long-distance switches, intended to profit from the synergy provided by digital technology.

It was imperative for Northern to announce the DMS line as soon as possible to make an end run around its competitors. On January 28, 1976, in Chicago, it sent out a press release launching the DMS "family." AT&T had just inaugurated (on January 17) its gigantic digital switch, the No. 4-ESS, also in Chicago. A few months later, Northern Telecom organized a seminar on the concept of a "Digital World" at Disney World, Florida, and Northern's two master marketing words, "family" and "world," were born: both refer to the global character of the new technology.

BNR kept Northern's promises: in October of 1977, the first DMS digital switch began operating at Disney World. This was marketing at its best. Events then reverberated throughout the telecommunications world like so many clarion calls: 1979, the roll-out of the DMS-100 and 200; 1980, the launch of the DMS-100/200; 1981, to market with the DMS-300; 1982, roll out of the DMS-250. The entire switching line was systematically gridded. At its May, 1979 meeting in Paris, the International Switching Symposium confirmed the triumph of digital over electromechanical. And Terreault was invited to chair the next ISS, planned for 1981 in Montreal. For Canada, this was the ultimate consecration.iv

1 On the transmission front, the first results came a bit earlier with the launching in 1962 of the T-1 multiplex transmission system.

i The conclusions of the long-term plan were summarized in an article: C. Terreault, "Planning the Telecommunications Network of the Future," Telesis, 2(2) (Spring 1972).
ii Terreault, interview with author, 6 Apr. 1990.
iii Special issue on the SL-1, Telesis, vol. 4, no. 3 (Autumn 1975).
iv Ryans, Northern Telecom, 12–17.


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