Thirteen years after launching ISDN (Integrated Services Digital Network) services, Nippon Telegraph and Telephone Corp. (NTT) said Wednesday the total number of ISDN lines has broken the 10 million mark.
The figure was passed earlier this month, on Dec. 8, and comes 18 months after the company announced subscriber lines had broken the five million-barrier, NTT said in a statement.
The explosive growth of ISDN is a result of the increasing popularity of the Internet and the massive amount of money the partially government-owned carrier has ploughed into expanding the service. ISDN is now available in all areas of Japan and is attracting users because it offers two digital telephone lines and faster Internet access along the same wire that was previously used for a single analog line.
To entice users to the service, which is popular with Internet users because both a PC and telephone can be used at the same time, NTT charges the same price for ISDN calls as for conventional analog telephone calls. In addition, it has launched a range of discount schemes targeted directly at Internet use.
The most recent of these is ISDN Flets that allows an unlimited number of calls to a specified Internet access point for a fixed monthly fee of around 4,500 yen (US$40). The unlimited use service, which was launched in late 1999, has proved a productive growth engine for ISDN.
The future of ISDN is not, however, as bright. Both ADSL (Asymmetric Digital Subscriber Line) and direct fibre optic services have just been launched by NTT that offer significantly faster data speeds than ISDN’s 64K bps (bits per second), and cable Internet services are also encroaching on ISDN’s core Internet user base.
NTT first launched ISDN in Japan in April 1988 and by the end of the year was serving just 1,000 lines. Subscriptions reached a million in 1996 as the Japanese Internet boom began. More than 2.6 million lines were in operation by the end of 1997 and the number had expanded to 4.4 million just one year later. After passing five million lines in the summer of 1999, the total had reached 7.4 million by the end of the year.