It is a type of high-speed network standard for Internet access, mainly used for broadband services over optical fiber. Here are the details of GPON and its main features:
1. Network Structure: GPON is based on point-to-multipoint
architecture, which means that a single fiber optic cable can serve multiple
locations using passive optical splitters. This is in contrast to the
point-to-point model, where each location requires its own fiber optic cable.
2. OLT and ONT/ONU: OLT (Optical Line Terminal): This is a
device located at the service provider's headquarters. It transmits data to
multiple users and also collects data from users. ONT (Optical Network
Terminal) or ONU (Optical Network Unit): This is a device located at the
customer's premises. It receives data sent from the OLT. The terms ONT and ONU
are sometimes used interchangeably, but ONT is usually customer facing and ONU
can refer to a larger device that serves multiple customers in some situations.
3. Speed and Efficiency: GPON offers asymmetric bandwidth
with downstream rates of up to 2.5 Gbit/s and upstream rates of up to 1.25
Gbit/s. However, there are advancements and new standards that can provide even
higher rates. The use of passive splitters in the network eliminates the need
for power in the distribution network, reducing maintenance costs and improving
reliability.
4. Wavelengths: GPON uses wavelength division multiplexing
(WDM), which allows multiple signals with different wavelengths (colors) of
light to be transmitted over a single optical fiber. Typically, two wavelengths
are used, one for downstream data and one for upstream data.
