EPON OLT/ONU transceivers

Ethernet Passive Optical Networks (GEPON or EPON) is the leading technology being used in FTTx (FTTH) deployments. PON is different than other optical network topologies in that it is a Point to Multi-Point (P2MP) topology. From the Central Office’s (CO) Optical Line Terminal (OLT, with SFP GEPON transceiver/module) a single strand of fiber goes out to a passive optical splitter where its signal is multiplied to 32(64) different lines. The Transmit and Receive signals operate on different wavelengths allowing bi-directional operation over a single fiber. Anything transmitted from the OLT is transmitted to all 32 lines. It is up to the customer’s system (Optical Network Unit - ONU) to determine what packets are for that customer. All other packets are discarded. The PON current standards have defined downstream data rates up to 1.25Gbps.