Even in three years, the study predicts the incumbent carriers will retain 90 percent of the market.

From 1992 to 1997, Northwestel was also an incumbent carrier in 819.

The incumbent local exchange carrier in 604 and 778 is Telus.

Put simply, yesterday's ruling could lead to an increase in the fees that other companies pay for connecting to the networks of incumbent local carriers.

In 1996 the following central office numbering plan was put in place by the incumbent local exchange carrier.

The main incumbent local exchange carrier is Bell Canada, plus some independent companies.

The incumbent local exchange carrier in 780 is Telus.

Bell Canada continues to be the incumbent local exchange carrier for London.

Elsewhere, incumbent carriers have challenged cities' rights to requisition new networks.

Sogetel is an incumbent local exchange carrier that serves multiple areas in Quebec.