ZyXEL Communications PLA-450 - V3.60, Руководство пользователя

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Chapter 4 Introducing the Web Configurator
PLA450 User’s Guide
44
The following table describes the labels in this screen.
Table 9 Summary: My Homeplug Network
LABEL DESCRIPTION
Statistics
MAC Address This field displays the MAC address of the powerline device detected by your
PLA450.
Rx PHY Rate This field shows the transfer rate of data received by the local device from the
selected remote device, measured in Mbps.
Tx PHY Rate This field shows the transfer rate of data sent the local device to the selected
powerline device, measured in Mbps.
Avg. Pre-FEC
Bit Error Rate
In powerline networks data is sent in physical blocks (PB). This field shows the
average percentage of errors in the physical blocks sent by the destination
device to your local device before the errors are corrected using FEC (Forward
Error Correction).
A high error rate may not necessarily result in a poor connection as PBs with
errors are discarded and the powerline device adjusts the signal to a frequency
to a level where fewer errors occur
Avg. Source PB
CRC Error Rate
This field displays the average CRC (Cyclic Redundancy Check) error rate of
transmission from the destination device to the local device.
The CRC error check is performed after Forward Error Correction. If the error
rate after FEC error correction is still high, then this indicates a lot of noise at all
frequencies on this section of your powerline. Data transmission rates are
reduced if there is a lot of noise on the line.
Avg. Dest PB
CRC Error Rate
This field displays the average CRC (Cyclic Redundancy Check) error rate of
transmission sent from the local device to the selected powerline device.
The CRC error check is performed after Forward Error Correction. If the error
rate after FEC error correction is still high, then this indicates a lot of noise at all
frequencies on this section of your powerline. Data transmission rates are
reduced if there is a lot of noise on the line.
Avg. Bits This field displays the average number of bits transferred over the connection
measured in Mbps. This represents the physical rate of data transmission (the
PHY rate) which includes not only the files sent on your powerline, but also line
overhead required to manage your network, such as error correction bits.
The PHY rate is the clearest indicator of the quality of your line.
•
If the PHY rate is close to the HomePlug AV maximum data transfer rate
(see Chapter 15 on page 123 ), then the quality of this section of the line is
very high, with very little attenuation. (See Avg. Attenuation for details on
attenuation).
• If the PHY rate varies between the maximum level and a lower level (such as
60 Mbps), there is noise on this section of your powerline. Attenuation is not
a factor.
If the PHY rate is steady at a lower level (such as 80 Mbps), this is caused by
attenuation and not noise on this section of your powerline
Avg. SNR This field displays the average SNR (Signal to Noise Ratio) measured in dB.
Use this to check the amount of noise on this part of your powerline network.
The higher the number the better the connection quality.
Noise on your powerline is usually caused by household appliances running on
your powerline. The motor of a refrigerator can create electrical interference. A
cell/mobile phone recharger which rapidly alternates between on and off can
also generate noise. Poor cable quality and installation can also cause noise. To
identify causes of noise on your network, disconnect an appliance connected on
this part of your powerline network and observe whether this reduces the Signal-
to-Noise ratio.