GPON OLT/ONU transceivers

Gigabit Passive Optical Networks (GPON) 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 GPON transceiver/module) a single strand of fiber goes out to a passive optical splitter where its signal is multiplied to 64(128) 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 2.5Gbps.