usually is less than 50 km. Since CD and PMD are not considered as the
restrictive effects at this level of bit rate and distance, monitoring of CD and
PMD in general is not required in PONs. However, this may not be true for
future PON systems with larger transmission distances and higher bit rates, such
as superPON and 100-Gbps Ethernet.
7.4 CONCLUSION
The progress in deployed PON has already achieved an astounding rate of
growth over the past few years, and is expected to grow exponentially over the next
few years. In order to enable robust and cost-effective automated operation, PON
systems should probably be able to intelligently monitor the physical state of the
network as well as the quality of propagating data signals, isolate specific impair- ...