Tuesday, November 7, 1995

Advanced Technology Seminar 2A: Fiber-Optic Subscriber Systems and Multimedia Communications


Fiber-optic is one of the most important technologies to build infrastructure for multimedia communications. With its enormous transmission capacity, optical fiber has already become major transmission lines for interoffice trunks.

As a next stage, it is of vital importance to deploy fiber-optic systems in subscriber networks in order to achieve end-to-end high-speed transmission capability. NTT is planning to shift the existing subscriber network from metallic one to the future optical-fiber network so that it could be an infrastructure for carrying future high-speed/broadband communications.

Fiber-optic subscriber lines have already been used to provide high speed digital leased lines, ISDN-PRI and frame relays. Telephone service is also multiplexed and carried over fiber-optic subscriber systems, which are now being widely deployed all over Japan.

There are several architectures to implement fiber-optic subscriber networks, which are Fiber-to-the-Office (FTTO), Fiber-to-the-Curb (FTTC), Fiber-to-the-Home (FTTH) and their modifications. NTT is deploying these systems depending on the area where the systems are installed.

In recent years, the "multimedia age" has been moving closer to reality, through such rapid technological progress in the field of information communication as the downsizing of computers, the use of digital technology on telecommunication networks, and advances in optical fiber technology.

However, it is still not clear which applications are attractive, profitable, practically useful and feasible in the future multimedia environment. NTT started a joint utilization test on multimedia communications so that various applications could be developed, used and evaluated on the NTT's network test bed.

NTT planned the joint utilization test for multimedia communication so that it could stimulate users and manufactures to develop and utilize new multimedia applications, and thus, potential traffic for future high-speed networks would increase. In the test, NTT provides high-speed multimedia networks with no tariff. Participants to the test are requested to join the test with their test plan in which new applications are utilized. Participants are to provide for their own systems, software and contents which will operate in conjunction with the test network. NTT and participants jointly carry out the test and evaluate how the network and application are used.

NTT is promoting to create and develop new applications truly useful for our society and people's lives through these experiments.