Optical Splitters are located in a nearby Fiber Distrution Hub (FDH). Each splitter in the FDH takes one fiber from the OLT in the CO and splits the two downstream wavelengths to 16, 32 or 64 customers. Each splitter also takes the upstream wavelength from each customer drop and combines the signals into the signal fed back to the OLT.

Optical splitters come in 16, 32 and (future 64) user capacities.
BPON and GPON can not be mixed in the same splitter.