Multimode cable is made of of glass fibers, with a common diameters in the 50-to-100 micron range for the light carry component (the most common size is 62.5). Multimode fiber gives you high bandwidth at high speeds over medium distances. Light waves are dispersed into numerous paths, or modes, as they travel through the cable’s core typically 850nm or 1300nm.
Single Mode cable is a single stand of glass fiber with a diameter of 8.3 to 10 microns that has one mode of transmission. Single Mode Fiber with a relatively narrow diameter, through which only one mode will propagate typically 1310nm or 1550nm. Carries higher bandwidth than multi mode fiber, but requires a light source with a narrow spectral width.
GPON stands for Gigabit Passive Optical Networks. GPON is a point-to-multi point access mechanism. Its main characteristic is the use of passive splitters in the fibre distribution network, enabling one single feeding fibre from the provider’s central office to serve multiple homes and small businesses.
A GPON network is capable of transmitting ethernet, TDM (Time Division Multiplexing) as well as ATM traffic. A GPON network consists of OLT (Optical Line Terminals), ONU (Optical Network Unit), and a splitter. The splitter will divide the signal when needed. The OLT takes in all of the optical signals in the form of beams of light from ONUs and will convert it to an electrical signal. OLTs normally support up to 72 ports. An ONU connects to end users and will send their signals back to the OLT.
A GPON network can reach up to 20 km and provide service up to 64 end users. GPON utilizes both upstream and downstream data by means of Optical Wavelength Division Multiplexing (WDM).