said by TomS_:
All of the PON implementations I have seen work by sending the same downstream signal to all ONTs, and this is achieved using 1xN way splitters. The ONTs pick out the data that belongs to them, and ignore the rest.
In the upstream direction the ONTs use a TDM based protocol, having time slots in which they can transmit.
Interesting, that quite different from the PON's I have worked with and yes I can see how it would work.
Let me ask you a question, if an ONT locks up and just sends continuous light how does one go about finding it and how many ONT's can be on a strand before timing gets flakey?