2012/3/22 Masataka Ohta <mohta@necom830.hpcl.titech.ac.jp>:
William Herrin wrote:
The entire optics is shared by all the subscribers sharing a fiber. Thus, the problem is collision avoidance of simultaneous transmission, which makes PON time shared with L2 protocols.
Hm... i'm thinking one transceiver might malfunction and get stuck/frozen in the "transmitting pulse" state, thus making collision avoidance impossible, kind of like a shorted NIC on a shared bus topology LAN, if just one subscriber's equipment happens to have the right kind of failure, and that's neglecting the possibility of intentional attack. Passive optically-shared fiber networks don't sound so hot in that case.
So, you share fiber by having one guy control one wavelength (color, e.g. red) and another guy control another wavelength (e.g. blue). That's not a usual PON but WDN PON.
-- -JH