GPON is an acronym for Gigabit Passive Optical Networking, which is currently the fastest fiber optic technology in that market right now. The terminologies of GPON emanates from passive optical network (PON) which is a system that brings optical fiber cabling and signals all the way from the Internet Access Provider to the end user.
By Cisco Eng. Shingie Lev Muringi
One local service provider which has managed to master and engineer the deployment of GPON in Zimbabwe is the Liquid Telecommunications team surging them to sit on 40Gbps capacity, with 21Gbps excessive window apart from nation’s current 19Gbps demand. Liquid Telecom has successfully deployed this fiber optic technology at very strategic points across all the countries’s cities thus giving ZOL, their retail arm the capability to offer such robust Fibroniks Internet services to every home. Depending on where the PON terminates, the system can be described as fiber-to-the-curb (FTTC), fiber-to-the-building (FTTB), or fiber-to-the-home (FTTH).
Before software-defined networking can be utilized to cut costs and increase network speed and flexibility, Service Providers have to understand the fundamentals first. GPON is not a simple engineering structure to setup since a lot of special technical knowhow is required to deal with tiny strands of fiber optic cables and integrating them to produce a certain desired throughput.
Passive Optical Networks consists of an Optical Line Termination (OLT) at the communication company’s office and a number of Optical Network Units (ONUs) near end users. Typically, up to 32 ONUs can be connected to an OLT. The PASSIVE simply describes the fact that optical transmission has no power requirements or active electronic parts once the signal is going through the network.
All GPON systems have essentially the same theoretical capacity at the optical level. The limits on upstream and downstream bandwidth are set by the electrical overlay, the protocol used to allocate the capacity and manage the connection. GPON is one of the latest technologies but the first PON systems that achieved significant commercial deployment had an electrical layer built on Asynchronous Transfer Mode (ATM, or “cell switching”) and were called “APON.” These are still being used today, although the term “broadband PON” or BPON is now applied. APON/BPON systems typically have downstream capacity of 155 Mbps or 622 Mbps, with the latter now the most common. Upstream transmission is in the form of cell bursts at 155 Mbps.
Multiple users of a PON could be allocated portions of this bandwidth. A PON could also serve as a trunk between a larger system, such as a CATV system, and a neighborhood, building, or home Ethernet network on coaxial cable.
Due to the continuous vibrancy in the ICT industry, the successor to APON/BPON is now GPON, which has a variety of speed options ranging from 622 Mbps symmetrical (the same upstream/downstream capacity) to 2.5 Gbps downstream and 1.25 Gbps upstream. GPON is also based on ATM transport. GPON is the type of PON most widely deployed in today’s fiber-to-the-home (FTTH) networks in new installations and is generally considered suitable for consumer broadband services for the next five to 10 years.
From GPON, the future could take two branches: 1. 10 GPON which would increase the speed of a single electrical broadband feed to 10G; and 2. WDM-PON would use Wavelength-Division Multiplexing (WDM) to split each signal into 32 branches.
A rival activity to GPON is Ethernet PON (EPON), which uses Ethernet packets instead of ATM cells. EPON should be cheaper to deploy, according to supporters, but it has not garnered the level of acceptance of GPON, so it is not clear how EPON will figure in the future of broadband access as the latter continue to offer the acceptable speeds and reliability for the modern market demands.