Optical data technology

Gigabit PON is an attractive FTTH broadband access technology because it meets the requirements of all carrier types worldwide and is also favored as a technology by the major network operators. Gigabit PON, also known as GPON, is a method of saving fiber optic infrastructure capacity using WDM multiplexing technology by sending up- and downstreaming data over a single fiber. At the same time, high speed IP traffic is realized over the Passive Optical Network (PON). GPON allows the fiber distribution structure to be cascaded over one or more optical distributors, unlike Ethernet-based point-to-point data transfer. This allows to save fiber terminations, because only one fiber has to be connected at the central office (point-to-multipoint -PTMP), whereas with optical point-to-point Ethernet every single user needs a fiber termination at the central distribution point (point-to-point - PTP). The GPON technology brings the optical fiber ports (splitter output ports) close to the user. This makes it easier to distribute from the last distribution point to each individual end user. GPON can be considered as the optical counterpart to coaxial distribution, where the coaxial splitter ports are also located close to the end user.

Ethernet technology has its electrical equivalent in a DSL-like point-to-point structure, where each user requires a separate connection to the central station.

GPON downstream data packets move from the Optical Line Termination (OLT - located in the central station) to the Optical Network Units/Optical Network Terminations (ONU or ONT - located in the end user area). This means that each ONU connected to a PON network receives the packet, but only the addressed ONU receives the information. Upstream, the data packets are transmitted according to the Time Division Multiple Access (TDMA) principle. With GPON all packets are AES encrypted and can only be decrypted by the corresponding terminal device.

The next generation of GPON are XGS-PON or also XG-PON2, which work with a speed of 10Gb/s downstream. The physical infrastructure can be reused as with GPO