Transmission media can and will be affected by the noise coming from inner and outer sources. That is when noise immunity factor kicks in. Since different types of media has greater or smaller affects by the noise it is necessary to choose type of media depending on situation. Noise is affecting data signals, but since fiber-optic does not use electric ...
Apart from a regular scheme with series of 1:N splitters in FDN, some networks, especially those with industrial grade for power, gas or electricity providers, require equipment and some network design skills to provide backup schemes for your PON network.
Theoretically there is a 3 ways to provide such kind of backups:
1. Protecting fiber damage - in this case 2:N type ...