By Peter Sinclair
The web is about to get faster. Digital Subscriber Line (DSL) technology, still relatively new in this country, has accelerated to warp-speed with the arrival of VDSL (the V stands for "Very-high-bit-rate").
Texas Instruments and Alcatel have announced a VDSL transceiver chip in which "multitone technology" will increase data
speed through conventional copper wire by up to 1000 times over current 56kbps modem technology.
Where existing DSL can deliver data at only a few megabits per second, VDSL can pump it both ways through an ordinary telephone line at approaching 30Mbps symmetrically, or download at nearly 60Mbps in an asymmetrical implementation.
Telecom, currently setting the pace in New Zealand with its ADSL JetStream product, is already paying "close attention" to the VDSL advance, according to spokesman Glen Sowry. In theory, it should be possible to deploy it using the existing infrastructure, he says.
Where ADSL requires the installation of DSL equipment in local exchanges, VDSL racks must be located even closer to the user to offset performance degradation on existing wires caused by the higher demands of the new technology. Its practical range is 1 to 1.5km compared with up to 3km for ADSL installations.
These would probably be installed in existing roadside cabinets which are already connected to local exchanges with fibre-optic cable, Mr Sowry says.
But it may take some time before VDSL becomes a reality. New processors are on the way, and it is hoped that a commercial solution complete with chips and software will be ready next year. Operator trials will get under way before the end of 2000.
High-speed video-transmission, as required for webcasts and online movies, promises to become a reality in the first years of the new millennium. Digital movies, mirage-like for so long, may be almost ready for prime time.
