For much of its early history, Bell Canada operated as the Canadian division of the Bell System. Development and manufacturing of their various telephony products generally took place in the US, and then, to avoid duty, were manufactured in Canada at their Northern Electric subsidiary, the Canadian analog to the US Western Electric.
Pre-1970s
Northern Electric spun off a subsidiary in 1934, Dominion Sound Equipment, originally to develop equipment for sound in movies. Over time, the division evolved in an attempt to use its design talent and manufacturing ability on third party projects. In 1937, this aspect became the Special Products Division. For many years the SPD was used as Bell Canada's R&D arm, although as before, most telephony designs were created at Bell Labs in the US. In 1949, the United States Justice department attempted to force AT&T to divest itself of its Western Electric subsidiary. As a result of this legal action, Western Electric sold its shares in Northern Electric to Bell Canada. In 1957, Northern Electric started its own research and development labs in Belleville, Ontario. Two years later, Northern Electric created the Northern Electric Research and Development Laboratories in Ottawa.
1970s
In 1971, Bell Canada and Northern Electric combined their R&D organizations and formed Bell-Northern Research. BNR's researchers pioneered the view that a telephone switch was best regarded as a special form of real-time computer, a view that was considered to be highly innovative in the 1970s. Although George Stibitz had foreseen this evolution at AT&T in the 1930s, subsequent generations of engineers, prior to the 1970s, regarded the switch as a piece of hardware, best hard-wired, to handle the basic telephone call where two parties connect, speak and hang up. In the 1960s, however, this view was coming under a great deal of strain. Increasingly, telephone users wanted to conference call, forward, and record voice greetings, so common today. Such features required more flexibility in the controller, leading to the development of computer-controlled switching machines, notably the Bell Labs − Western Electric 1ESS. These early machines still had an analog, usually electromechanical switching matrix because the technology of the time did not permit the cost-effective dedication of a filter-codec to each subscriber. Northern Electric introduced its first electronic central office system in 1969 with the SP1. The SP1 had a fully computer-based electronic control system, thus the name "SP," short for "stored program." Its switching matrix was still electromechanical. Rather than the reed relay matrix of the 1ESS, it used the minibar, a version of the crossbar switch. BNR was, with Northern Telecom, a part owner of MicroSystems International a semiconductor manufacturer based in Kanata, outside Ottawa.
BNR introduced the Meridian SL-1 in 1975, the world's first all-digital PABX aimed at medium-sized businesses. The SL-1 was fully digital in both control and switching. As such the SL-1 was smaller, much more reliable, and offered many more features than an equivalent electromechanical system. The SL-1 design evolved into Meridian-1, and subsequently the CS1000x as Nortel's private network flagship offering. The SP-1 design was superseded by the DMS-100 central office switch and other members of the DMS family of products. DMS extended the technology by fully integrating switching and transmission. This was a major advance that changed the way systems were built. BNR's products were architecturally based on Complex Instruction Set architectures prevalent in the 1970s, and on a series of underlying technologies. This was greatly influenced by the late 1970s success of the DEC VAX computer, a highly "elegant" and rather layered technology, realizable in a range of power. In the early 1990s, under Nortel CEO Jean Monty, the software for the flagship DMS product was segmented into layers to improve maintainability of the product. The IEC layers were customer-specific, targeted towards Sprint, MCI, and a large group of small "United Carrier" companies that were subsequently swallowed up by Worldcom. Once the IEC layer was established, customer-specific releases could occur quarterly, whereas Telecom and Base programming was for baked-in code that only had infrequent, maintenance updates.
With the formation of Bell Canada Enterprises in 1983 as the parent company of Bell Canada and Northern Telecom, BNR in Canada was jointly owned 50-50 by Bell Canada and Nortel. Nortel assumed a majority share in BNR in 1996, and BNR was gradually folded into Nortel, which acquired the remainder of BNR when BCE divested itself of Nortel. Unfortunately, the collapse in demand for Nortel products in the wake of the bursting of the dot-com bubble, which occurred after aggressive spending on acquisitions and hiring under CEO John Roth, required Nortel to trim its workforce from 96,000 to 35,000 people.