Data Connect 5201-BM, Руководство пользователя

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2
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 subsequently isolate
and eliminate the source of noise.
Generally speaking, the higher SNR value gets better line
quality, but lower performance.
Q7: What is profile and what’s the benefit?
A7: 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 17a profile
is selected that provides long distance transmit with similar
performance, when 30a profile is selected that provides
short distance transmit with wire speed performance.