PLANET VC-201A - Manual (Page 30)

30
Q6: Can VC-202 compatible with VC-202A?
A6: Currently NO. Although VC-202 (profile 12a) and VC-202A
(profile 17a) is base on ITU-T G.993.2 VDSL2, but with
different Profiles, so far they are not compatible with each
other.
Q7: What is SNR and what’s the effect?
A7: In analog and digital communications, Signal-to-Noise
Ratio, often written SNR, is a measure of signal strength
relative to background noise. The ratio is usually measured
in decibels (dB).
In digital communications, the SNR will probably cause a
reduction in data speed because of frequent errors that
require the source (transmitting) computer or terminal to
resend some packets of data. SNR measures the quality
of a transmission channel over a network channel. The
greater the ratio, the easier it is to identify and subse-
quently isolate and eliminate the source of noise.
Generally speaking, the higher SNR value gets better line
quality, but lower performance.
Q8: What is band plan and what’s the effect?
A8: VDSL2 defines multiple band plans and configuration
modes (profiles) to allow asymmetric and symmetric
services in the same binder (by designated frequency
bands) for the transmission of upstream and downstream
signals. User has the ability to select fixed band plan.
When Symmetric is selected that provides better down-
stream performance, when Asymmetric is selected that
provides better upstream performance