3.1.1.3 Digital Main Lines

Along with the general expansion of the telephone network in Iran, the percentage of digital main lines has also been increasing. In 1991 only 12.58% of the main lines in operation were digital. This percentage rose to about 48% at the end of the first five-year plan in 1994 and it rose to 62.58% in 1997, which translates to about 4,076,000 digital main lines in 1997. Table 3.5 shows the percentage of digital main lines in Iran from 1991 to 1997.

 

Table 3.5: Percentage of Digital Main Lines in Iran

Year	% of Digital Main Lines
1991	12.58
1992	32.20
1993	37.53
1994	47.98
1995	50.66
1996	56.43
1997	62.58
1999	> 80 (estimate)

 

So far TCI has converted about 55% of existing lines to digital lines, while more than 90% of newly installed exchanges are digital. The current total percentage of digital main lines is estimated to be over 80%.