Cable capacity up with new inter-island link

RICHARD BRADDELL reports that Telecom is bringing the North and South Island closer.

Telecom is investing $38 million on a submarine cable linking the North and South Islands to cope with exponential growth in internet and multi-media.

The project includes laying another cable between Christchurch and Greymouth, providing an alternative route should existing links be cut.

Due for completion in the middle of next year, the Cook Strait cable will be laid by Siemens, the company that installed Telecom's ATM broadband network backbone three years ago.

About half the $38 million price tag will be spent within New Zealand.

The 200-kilometre submarine cable will run between Nelson and Hokio Beach near Levin, bypassing earthquake prone Wellington. It will have an expected life of 25 years and has the capacity to let every South Islander watch separate high-quality digital television channels.

The cable projects should pump about $19 million into local economies.

The cross-strait link will remove Telecom's dependence on Transpower-operated fibre optic cables that run beside each other and carry the vast bulk of telecommunications traffic between the islands.

That link came under threat two years ago when a fishing boat snagged one of the cables, leaving the nation's entire telecommunications traffic between the two islands hanging on the remaining cable and limited capacity microwave radio links.

To overcome the risk of being snagged by fishing boats, Telecom's cable will be buried two metres below the sea floor.

Unveiling the project yesterday, Telecom's general manager of access and delivery, Richard Dammery, said the extra capacity was vital as telecommunications traffic doubled every two years.

Telecom is not alone in building a cable, with Telstra Saturn earlier this year naming Ericsson Communications as the prime contractor on a submarine cable project worth about $90 million linking Auckland, Wellington and Christchurch and points in between.

Even while Telecom's 24 fibre optic strand cable will be half that of Telstra Saturn's, its capacity will be huge. Using a technology known as dense wave division multiplexing, the light fired down the cable can be broken into separate colours. If fully utilised, Telecom's cable would have a capacity of 3.2 terrabits a second, or sufficient for a quarter of the world's data traffic at the present time.

Asked, given Telstra Saturn's project, if New Zealand was in danger of becoming overbuilt, Dr Dammery said that the growth in demand was such that both projects had their place.

Dr Dammery said Telecom was open to offers to either sell or exchange cable bandwidth with competitors to step up security in both networks.

Answering a question on whether the additional capacity was being put in to match Telecom's plans to resell Sky Television, he simply reiterated that it was being built to meet burgeoning demand.

Telecom's new ADSL-based high bandwidth product, Jetstream, was an example of the demand - it had 4000 customers now and a potential user base of 600,000.