France Telecom plans fiber trials

France Telecom plans fiber trials

DAVE WILSON

During the next three to four years, France Telecom plans to invest more than $200 million in pilot services based on fiber-optic network technology for the information superhighways of France. Furthermore, trial projects, such as interactive television, are expected to involve partnerships with services providers, as well as provide network platforms for subscriber services.

The first of these fiber-to-the- curb and fiber-to-the-building networks is scheduled to be installed in 1996, enabling French customers access to broadband interactive services, including video-on-demand, telephone, broadcast cable and high-speed data services for access to Telnet and the Internet.

The French telecommunications giant also plans to incorporate into its $100 million fiber-optic information superhighway initiative a system jointly developed by Broadband Technologies and S.A.T. The partnership, also known as Group Sagem, will provide the fiber-based access platform to deliver telephony, interactive video services and high-speed data communications to 20,000 French homes.

Although France Telecom has not indicated where those homes are located or what equipment will be used, there are four sites where these systems will be deployed--one of which will most likely be Paris.

The agreement between the companies comes just two months after Research Triangle Park, NC-based Broadband Technologies shipped its fiber loop access, or FLX, system to France Telecom for testing and development to demonstrate the potential of switched-digital fiber-to-the-curb and fiber-to-the-building networks.

This switched-digital video system runs over a fiber-to-the-curb network. Once at the curb, the fiber fans out between 20 and 30 homes. Each home is then capable of receiving interactive, two-way video, voice and data communications.

The system has three elements, including the host digital terminal, the optical network unit and the super trunk. Residing at the central switching office, the host digital terminal is the heart of the system and provides the switch interface, software processing and optical interfaces.

The optical network unit provides the optical termination and the interface to the customer. Channel units are plugged onto the unit to provide telephony services. Customer drops connect each unit--situated on a pole, a building wall or on the ground--to 64 homes. The supertrunk provides an asymmetric digital-video distribution from the video headend to the host digital terminal.

In an interactive television distribution network, the fiber loop access switched-digital video system must work with an asynchronous transfer mode, or ATM, switch. Such a bundled system, known as the SLC-2000 Access System, has been demonstrated in the United States by Broadband Technologies and AT&T.

For example, at the March 1995 Supercomm trade show in Anaheim, CA, an end-to-end architecture for interactive video was presented. The demonstration united the fiber loop access system with set-top boxes from Philips Consumer Electronics and Compression Labs, and an information server from Digital Equipment Corp.

ATM-edge switch

In its U.S. system, the ATM switch maps encoded programming onto a synchronous optical network-compliant signal for downstream transport to the host digital terminal. This terminal--an ATM-edge switch--routes the programming out to the optical network unit closest to the customer. From there, the video programming goes directly over twisted-pair and coaxial-cable drops into the house wiring to a set-top box.

The ATM cells continue to the set-top box, personal computer or integrated appliance. The result is an ATM system that provides bandwidth-on-demand for multiple services directly to the customer.

The analog headend of the system acquires traditional television programming as radio-frequency signals, converts them to optical signals and delivers them to end users via AT&T`s linear lightwave system. At an AT&T video power hub out in the loop, optical signals are converted back into radio frequency and distributed to the user over a coaxial-cable system. At the optical network unit, the analog and digital video signals are combined onto a single drop to the home.

The Broadband Technologies/S.A.T system is expected to be similar to the one that Broadband has developed in the United States with AT&T. This system is expected to integrate Broadband Technologies` second-generation interactive switched-digital video platform--the FLX-2500--with S.A.T`s telephony and telecommunications equipment.

"In the French system, U.S. equipment will support the France Telecom ATM switch over a standard protocol," says Krish Narashimhan, manager of the Advanced Technology Group at Broadband Technologies headquarters. "I suspect that France Telecom already has its ATM switches selected; the vendor could be any major player--perhaps Alcatel or Siemens--in the ATM switch market," he adds.

The linear lightwave transmitter--this time manufactured by S.A.T.--may be kept in the system, but the video/power hub may be gone. "It isn`t quite the same architecture that may be deployed in France," says Narashimhan. "A considerable amount of the project is fiber to the building, so the power hub is expected to be implemented differently. Because there is adequate power available in a building, the power source may be derived directly from the building," he adds.

Europe represents a huge market for vendors who want to sell their telecommunications wares into the lucrative interactive television marketplace. According to Broadband Technologies, there are 172 million access lines and 142 million TV households in Western Europe alone. And if the Eastern European countries are included, the numbers rise to 222 million access lines and 283 million TV households. By any analyst`s calculations, that means mega-fiber deployment. q

Dave Wilson writes from London.

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