Accton Technology VS4512DC Management Manual page 89

Profile Name
A5-50-7
A6-22-3A
A7-40-5A
A8-46-7A
TLAN
Max-Rate
Noise margins should be configured to a level appropriate to the actual noise
level of the environment. A noisier environment requires a higher noise margin
to ensure a stable link. The noise margin only comes into effect after a link is
activated. Increasing the noise margin can result in the switch choosing a lower
profile. This will provide a link with a longer range but a lower data rate.
Example
The table below gives an example of a noise margin for a given profile and
theoretical minimum SNR.
Profile Name
S1-16-16
Range; 0-9 dB. Default: 0 dB
• Interleave – Interleaving improves Reed-Solomon error correction when there
is pulse noise. A greater degree of interleaving will provide more protection
against pulse noise but will increase transmission delay and reduce the
effective bandwidth of the link. The degree of interleaving can be increased by
increasing the following parameters:
- M – The interleaving depth index.
Range: 0-64, Upstream default value: 8, Downstream default value: 16
- I – The interleaver block length.
Options: 4 or 8; Upstream default value: 8, Downstream default value: 8
Theoretical Minimum Signal-to-Noise Ratio (dB)
DS1
35
26
32
35
32
41
Downstream Upstream Rate
Rate (Mbps) (Mbps)
16.74 10
DS2 US1
26 23
10 17
23 17
26 23
10 29
41 41
SNR
20
VDSL Configuration
US2
14
10
Not Used
14
10
41
Noise Margin
(dB)
6
3-59