Final tests on £20m undersea cable

Telecom Eireann will today run last minute tests on a new, £20 million fibre optic cable running from Kilmore Quay, Co Wexford, to Oxwich Bay, Wales. The Solas cable, which is owned equally by Telecom Eireann and Cable & Wireless, will be able to route up to 60,000 calls per second from this weekend.

A Telecom spokeswoman said the new cable forms a vital part of the Solas ring, linking Irish telecommunications to Britain and the United States. An "inner ring" now routes traffic between Dublin, Belfast, Blackpool, Bristol, Oxwich Bay and Kilmore Quay. An "outer ring" extends beyond Blackpool to Manchester, London, Cornwall and Oxwich Bay.

The latest link of the cable means that calls and data can be routed in either direction around the ring. Telecom Eireann yesterday described the Solas ring as fully self-restoring and the company's most sophisticated to date.

This means that each call is actually sent in both directions, with the customer using the shortest link. Should a problem occur on the shortest route, however, the call is switched to the longer route. Because this process takes 5 hundredths of a second, the customer is unlikely to notice that there is a problem.

The fibre optic pipe uses synchronous digital hierarchy (SDH) technology, and currently sends data at 5 gigabits per second. The company said the significance of the new cable lay in how quickly it could be enhanced and improved. Capacity could be easily upgraded to 120 gigabits per second and more as demand grows, Telecom added.

While Telecom Eireann owns the part of the Solas ring in the Republic with Cable & Wireless owning the rest, the two firms split evenly the £20 million cost of the new cable. A spokeswoman for Telecom said the Irish firm owns 50 per cent of the capacity of the entire cable, rather than the first half of the pipe. This benefited business customers, she added, because they need only negotiate with one telecommunications company.