VDSL（Very-high-bit-rate Digital Subscriber loop） is a DSL broadband network technolgy,
a new generation of digital technology to expand existing telephone line(twisted-pair copper wire)transmission frequency band width. Which modulate the analog voice and non-voice signals into the encoded digital signal, then demodulated and received at
the central office.VDSL technology solve the problem of high-speed receiver, which is commonly known as the "last mile", by the traditional
telephone line to meet high-speed network environment of multimedia services, such as VoIP, IPTV, visual
communication and so on. The WD-V**1 (M) / V**1 (S) provide point-to-point solution,which are widely used in coal mines, factories, railways and other
long-distance network transmission.
