Passive Optical Networks

CNR curves are plotted while setting the CATV power level to its minimum

sensitivity level (i.e. 6 dBm), sensitivity level 1 dB, and sensitivity level þ 1dB.

CNR degradation is observed with increasing downstream data signal power, and

the CNR limit of 41 dB is reached at 42-dBm digital cross talk.

4.7 SUMMARY AND OUTLOOK

This chapter has outlined the system requirements, enabling technologies, and

system evaluation methodologies covering the various aspects of the current

status of optical transceivers in the context of PON applications. PON trans-

ceivers are unique bidirectional devices that use different wavelengths to transmit

and receive signals between the OLT and the ONUs over a single fiber. The

different types of PONs, i.e. BPON, EPON, ...