VDSL vs G.fast | difference between VDSL and G.fast

This page compares VDSL and G.fast and mentions difference between VDSL and G.fast. The other difference between terms are provided here.

Both VDSL and G.fast are digital subscriber line standards used for data transmissions. Let us understand main difference between VDSL and G.fast.

Specifications	VDSL	G.fast
Full form	Very high bit rate digital subscriber line	Fast access to subscriber terminals
Frequency	up to 30MHz	2 to 106 MHz , 2 to 212 MHz planned for future profiles
Maximum data rate	100 Mbps in both upstream and downstream (VDSL2)	1 Gbps over distance of 70meter 800 Mbps over distance of 100 meters 500 Mbps over old shielded type of cable (distance of 100 meters)
Modulation type	DMT (Discrete multi-tone modulation) e.g. OFDM (Orthogonal Frequency Division Multiplexing)	OFDM , Refer FDM vs OFDM
Number of sub carriers in a FFT	4K	2K (in 106MHz profile)
Duplexing method	FDD (Frequency Division Duplex)	TDD (Time Division Duplex), Refer TDD vs FDD
OFDM symbol time	approx. 250 µSec (in 17MHz profile)	pprox. 20 µSec
Vectoring method	using ITU-T G.993.5	supported along with adaptations required for high frequency
Transmit power	It depends on profile, 14.5 dBm	4 dBm
FEC type	RS Coding (Reed Solomon Coding), trellis coding	RS Coding (Reed Solomon Coding), trellis coding
bits per DMT frequency carrier	15 (in VDSL2)	12
Impulse Noise Protection	Available in VDSL2	Available
Standard	ITU-T G.993.2, ITU-T G.993.5	ITU-T G.9700, G.9701

VDSL and G.fast RELATED LINKS