VDSL2, Very High Speed Digital Subsciber Line, is a broadband variant of VDSL, with data rates of up to 100 Mbit/s in the downlink and uplink over a range of 200 m and 500 m, respectively.
In addition to the frequency band of VDSL, whose frequency band extends to 12 MHz, VDLS2 uses the frequency band above it from 12 MHz to 30 MHz. The entire frequency range is divided into 4,096 channels with a bandwidth of 4.3125 kHz, which are modulated using the multitone method. For VDSL2, there are various band plans with different bandwidths, a different number of carriers with different transmission powers.
Like ADSL, VDSL2 uses the multitone method( DMT) and offers many of the technical features of ADSL2. VDSL2 always provides the same bandwidth to the end user and is suitable for triple-play services such as VoIP and interactive video services such as video-on-demand in HDTV, for video conferencing and telecommuting.
Symmetrical and asymmetrical transmission
VDSL2 can operate with symmetrical and asymmetrical transmission. With symmetrical transmission, the range is 350 meters. There is also a version for longer ranges, long-reach VDSL (LR-VDSL). With asymmetrical transmission, ranges of up to 5 km can be bridged with LR-VDSL, whereby the data rate decreases as the range increases. With LR-VDSL, the frequency band between 25 kHz and 138 kHz is also used.
The aforementioned transmission speeds can be increased considerably by vectoring, supervectoring and line bonding. Both methods are implemented with dynamic spectrum management( DSM). For example, data rates of 500 Mbit/s have already been achieved with line bonding, and 100 Mbit/s in the uplink and downlink over 300 m with vectoring. Another connection technology for copper twisted pairs, whose data rate far exceeds that of VDSL2, is G.fast.