VDSL – The Story So Far

Written on 3:08 PM by ooe

The introduction of ADSL (Asymmetric Digital Subscriber Line) to drive forward the interactive broadband revolution is now well underway. ADSL is providing consumers with unprecedented high speed access to the Internet, and has sufficient capacity to deliver video and high speed data to the majority of homes. But ADSL is not the end of the story; demand for bandwidth will continue to grow and telecommunications network operators are developing the ability to deliver capacity far beyond ADSL using an exciting new technology called VDSL (very high speed digital subscriber line).

Like ADSL, VDSL operates on existing telephony wire pairs and is therefore a natural step for network operators who own an extensive telephony infrastructure. The key difference between ADSL and VDSL is that VDSL relies on deployment of optical fibre deep into the access network to reduce the distance over which data has to travel on the wire pairs, thereby reducing cable losses and increasing capacity.

The UK network includes both underground and overhead cables and is fairly typical of the networks to be found in most developed countries. This fact is relevant because it is important that VDSL technology is internationally standardised to reduce equipment costs, and it is helpful that most network operators have similar network constraints.

The distance from cabinet to customer is typically less than 1 km and provides the opportunity to access the final drop to connect VDSL transmission equipment. Fibre will used to backhaul the broadband services from the cabinet to the nearest broadband access node.