U.K. power utility to string fiber for voice and data services

U.K. power utility to string fiber for voice and data services

david wilson

Based on its comprehensive private telecommunications infrastructure, Norweb in Manchester, England, a regional electricity company to more than 4.7 million customers, has assembled a new operating division, Norweb Communications, to offer public voice and data services over fiber-optic networks. In April 1994, London`s U.K. Department of Trade and Industry granted the company a Public Telecommunications Operators license, just for this purpose.

During the next three years, Norweb Communications plans to expand its telecommunications infrastructure deeper into its operational area. It owns a large network of telephone cables, many terminating in the distribution network substations at major business premises. This existing network is expected to be used to supply advanced telecommunications and data services via a metropolitan synchronous digital hierarchy fiber-optic loop and copper wire drops.

Norweb`s SDH network is currently under construction. Once completed, it will provide an inner city fiber-optic ring in the Man chester city center. This area covers the financial and commercial sectors of Manchester, thereby offering the potential of delivering diverse information services to numerous businesses located near the ring. A second fiber-optic ring, dubbed the Greater Man chester metropolitan ring, will connect nearby areas such as Bolton, Bury and Rochdale. To implement its fiber-deployment strategy, the company has awarded a three-year contract to GPT Public Networks, Liverpool, England, for fiber-optic multiplexers.

The inner city ring will comprise three SDH nodes operating at synchronous transport module, level 1 (155.52-megabit-per-second) rates. The nodes will be located at Linley House, Cannon Street and Deansgate in the center of Manchester. If there is a need for extra capacity, the rings will be expanded to STM-4 (622.08-Mbit/sec) rates by adding STM-4 line cards into the existing STM-1 multiplexers, or extra fiber will be used to create concentric STM-1 rings. The optical fiber, supplied by BICC Cables Ltd. Division, Pirelli Cable Corp. and NKF Kabel BV, will be installed overhead and underground--predominantly underground in the city center.

The expansion of the existing communications network is being carried out partly through the refurbishment of the Norweb 132-kilovolt overhead distribution network. Several techniques will be used to install the overhead fiber. Where refurbishment of the network is already underway, an optical ground wire will be used: Optical fibers will be installed by replacing earth conductors with those that incorporate an optical fiber cable. In other cases, where refurbishment is not required, an all-dielectric self-supporting cable, or a cable that is strung under the power lines between pylons, will be used. Another technique calls for wrapping a cable containing optical fibers over a power line between pylons. This system can be deployed over the company`s 275kV network.

Norweb also plans to take advantage of installed ducts within the city center to provide individual organizations with optical fiber interconnects. According to the company, these fiber interconnects can be linked directly from tributary ports on the SDH multiplexer using low-rate virtual container transport. Norweb expects to expand the SDH network to provide the same services to businesses in Greater Manchester areas--the City of Salford, Tameside, Trafford and Stockport.

But the network is not going to be strictly fiber. Within the Manchester city center, many electricity substations furnish electricity distribution to the business community. These substations are interconnected for telecommunications purposes via 2500 miles of copper pairs. By taking advantage of this infrastructure, and using high bit-rate digital subscriber line technology, Norweb intends to provide 2-Mbit/sec data transmissions to customers from the SDH ring over distances of a few kilometers. The 2-Mbit/sec data rate will be split over two copper pairs, each pair carrying full-duplex 1.04-Mbit/sec data signals At the customer premises, primary rate multiplexers, routers and voice/data equipment will be deployed, depending on network requirements.

To provide telephony services that will allow users to make national and international calls, Norweb has signed a preferred carrier agreement with Energis in London, the new long-distance network operator owned by the National Grid Co. The National Grid Co. is owned by the 12 regional electricity companies. Norweb is also holding discussions with British Telecommunications and Mercury, both in London, relating to interconnect agreements. n

David Wilson writes from London.

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