Saturated optical power, Copper transceiver modules, Data rate – H3C Technologies H3C S12500 Series Switches User Manual
Page 13: Transmission distance, Connector
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Saturated optical power
Saturated optical power (also known as optical saturation) is the maximum receive power at a given data
rate and bit error rate range (10
-10
to 10
-12
), in dBm.
Saturated photocurrent occurs if a fiber probe is irradiated by intensive light. When this occurs, it takes
the probe some time to recover. In this case, the receiving sensitivity worsens and the received signals
may be decided incorrectly, causing bit errors. This will probably damage the receiving probe. Therefore,
when you perform operations, try to maintain a normal saturated optical power level.
Copper transceiver modules
Copper transceiver modules are used for transmitting signals over Category-5 unshielded twisted pair
(UTP). UTP transmission cover shorter distances than optical transmission and can be used in small-sized
networks only.
H3C devices support only SFP copper transceiver modules.
Data rate
The data rates of copper transceiver modules supported by H3C devices are 1250 Mbps.
Transmission distance
Through UTP cables, electrical signals can be transmitted over a distance of 100 m (328.08 ft) only. This
is because electrical signals attenuate during transmission through the UTP cables.
Attenuation refers to the dissipation of the power of a transmitted signal as it travels over a cable.
Attenuation occurs because signal transmission suffers certain resistance from the cable, which weakens
the electrical signals as they travel over the cable. When signals are transmitted over a very long
distance, signal strength decreases very significantly, causing the signal-to-noise ratio to drop below the
accepted level. This makes it impossible to distinguish between signals and noise, resulting in decision
errors.
When signals are to be transmitted over a short distance, use copper transceiver modules only.
Connector
RJ-45 (Registered Jack-45) twisted pair connectors are used as the connectors for copper transceiver
shows the appearance of an RJ-45 connector.
Figure 6 RJ-45 connector