UMN:CLI
User Manual
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13 GPON Configuration
Gigabit Passive Optical (GPON) technology has the active network elements OLT (Opti-
cal Line Termination) at the central office and ONU/ONT (Optical Network Unit / Termina-
tion) at the subscriber site.
Typical GPON configuration consists of a single PON port at the OLT and a number of
ONUs connected to it over a single fiber feeder.
Generally, a Time Division Multiplexing (TDM) is used in the downstream data transmis-
sion. OLT broadcasts data to every ONUs using TDM approach. Every ONU receives
each downstream frame and pinks up only that data addressed to it by the OLT.
To deliver data to OLT in upstream direction, the OLT implements a Time Division Multiple
Access (TDMA) approach. ONU (ONT) receives data from the user ports and combines
them into bursts. Each ONU (ONT) transmits its data in a strict accordance with the
Bandwidth Map generated by OLT for the synchronization. Using DBA mechanism OLT
can rearrange upstream bandwidth to provide more resources to those ONU tightly load-
ed with traffic.
The ONU provides network termination for a Passive Optical Network (PON) in the home
or business. The ONU connects via a high speed interface to the PON network and pro-
vides subscriber access to data (Ethernet), voice (POTS) and video services. GPON
gives edge networks an unparalleled bandwidth advantage in their ability to offer truly
high speed triple play service (i.e. voice, video and data) especially when compared with
existing cable or DSL services.
The following figure is the example of the GPON network set up.
Fig. 12.2
Example of GPON Network
