During operation, the ONU and OLT may continuously monitor the fluctu-
ation of RTT due to changes such as temperature fluctuation, and perform fine
adjustment by updating the RTT register value.
2.5.3 C-Band Analog CATV Signal Overlay
In addition to broadband data delivery, TV program distribution was envi-
sioned as a primary PON service in the very beginning. As pointed out in Chap. 1,
analog TV services have been distributed using the 1550-mm wavelength in an
HFC system for a long time [5]. Despite its limitations, one way analog broadcast
TV is a simple and efficient method to stream video services to a large group of
users.
A quick and easy method to offer TV services on a TDM-PON is to directly
broadcast analog TV signal to end users on the