switches that could be acquired at a relatively-low cost. The wire line facilities along the highway was changed from ring-down services to multi-party lines off dial exchanges as the communities along the line received central office switches, most of which were Ericsson Rurax switches, which were modified in the late 1970s to enable direct dialing of long-distance calls but without automatic number identification. The more remote multi-party lines were switched from wire to Exicom radios, and most of the Ruraxes were replaced in the mid-1980s with modern solid-state digital switches. However, the last Rurax remained in service in Swift River until 1987. The three local independent companies in the Northwest Territories were connected to the CNT long-distance network by 1961 and additional locations in 1962, as CNT extended its telephone service mandate into the vast territort (by then, Bell Canada was operating in Frobisher Bay, in the east). In July 1961, CNT purchased the Hay River Telephone Company; on 31 December 1963, CNT purchased the Yellowknife Telephone Company (at $250 per share); and in May 1964, CNT purchased the exchange in Fort Smith. Around 1961, the company name was changed from Canadian National Telegraphs to Canadian National Telecommunications. The original pole line along the Alaska Highway was overbuilt by a modern analogue microwave line which was contracted for between CNT and the US Department of Defense on 25 March 1959 and completed in 1961. Like much of the northern long-distance infrastructure, a long-term government contract was required to make the cost affordable. In this case, it was the US military's need for a reliable link to its Alaska radar stations. The CNT link joined Alascom microwave facilities with Alberta Government Telephones (now Telus) microwave facilities. Other US Department of Defense contracts with CNT resulted in tropospheric scatterwave facilities being installed to link up Distant Early Warning Line sites along a line stretching from Barrow, Alaska, to the east side of Greenland, with a scatterwave antenna in Hay River, Northwest Territories. These facilities, such as the ones between Elsa, Yukon and Arctic Red River (now Tsiigehtchic), Northwest Territories, which was completed in 1960, were also used meanwhile to carry civilian long-distance circuits until satellite facilities were implemented in the 1980s. The microwave system on the Alaska Highway was inaugurated with a phone call from Canadian Prime Minister John Diefenbaker, who was visiting Whitehorse, to US President John F. Kennedy in Washington,