Gary Hughes wrote: > The FiOS network uses 3 wavelengths on the PON to the > home, two downstream, one upstream. Not to split hairs too much (but I will anyway), but I've read that they are using DWDM, hence 30-odd carriers. And with the PON design, it must mean that each home is visited by all of these. Just passive splitters and combiners in this last-mile optical network. However only some number of these optical carriers, and I think you're probably right when you say that's 3 carriers, are actually used in each premise. That outside box, the ONT, must block all the but the needed ones. It seems impossible to get the complete story. My guess is this: If 30 homes can be served by a single PON, as some articles claim, then that must mean that one frequency is used for all standard TV channels, and split 30 ways. Another frequency is used for upstream traffic for all 30 homes, and the energy from each combined. They may get time slots when they are allowed to transmit. That leaves 30 frequency channels that could be dedicated to one home each, for broadband downstream. Seems like the optical budget is a bit difficult, to say the least, but I see no other way to serve 30 homes with each DWDM PON. Easy enough to serve 10 homes, though! Bert ---------------------------------------------------------------------- You can UNSUBSCRIBE from the OpenDTV list in two ways: - Using the UNSUBSCRIBE command in your user configuration settings at FreeLists.org - By sending a message to: opendtv-request@xxxxxxxxxxxxx with the word unsubscribe in the subject line.