In recent years, Fiber to the Home (FTTH) has started to be taken seriously by telecommunication companies around the world, and enabling technologies are being developed rapidly.
PON has recently attracted much attention due to its low cost and high performance. In this post, we are going to introduce the PON which mainly involves the basic components and related technology, including OLT, ONT, ONU and ODN.
First of all, it is necessary to have a brief introduction of PON. In contrast to AON, multiple customers are connected to a single transceiver by means of a branching tree of fibers and passive splitter /combiner units, operating entirely in the optical domain and without power in PON.
There are two major current PON standards: Gigabit Passive Optical Network (GPON) and Ethernet Passive Optical Network (EPON). But no matter which type of PONs, they have a same basic topology structure. A Gigabit Ethernet Passive Optical Network (GEPON) system is generally composed of an optical line terminal (OLT) at the service provider’s central office and a number of optical network units (ONUs) or optical network terminals (ONTs) near end users, as well as the optical splitter. In addition, the optical distribution network (ODN) is used during the transmission between OLT and ONU/ONT.
What are their differences? To describe simply,
OLT means Optical Line Terminal.
ONU is the Optical Network Unit.
ONT means Optical Network Terminal.
OLT use fiber cables, adapters and others to connect with ONU and ONT, in order to build 
ODN (Optical Distribution Network).Both of ONU and ONT are client-side devices, no difference in nature, but if you have to distinguish, it can be seen from the name difference.ONT is the optical network terminal, applied to the end user, and ONU refers to the optical network unit, which is with the end user. There may be other networks.Give a simple example, such as in a district, ONT is directly on the user’s home equipment, and ONU may be placed in the corridor, each user through the switch and other equipment connected to the ONU.
Optical Distribution Network (ODN) is an indispensable path for transmitting Passive Optical Network (PON) data and directly affects the performance, reliability, and scalability of a PON system. The ODN, an integral part of the PON system, resides as the physical path for optical transmission between the OLT and the ONT. Its reach is 20 km or farther. Within the ODN, optical fibers, fiber optic connectors, passive optical splitters, and auxiliary components collaborate with each other.
For example,
TARLUZ 1U rack OLT with 2-PON port is OLT, TARLUZ 6200 EPON is ONU：
There are different types of OLT, ONU, ONT equipment for GEPON, which are the new generation PON equipments and mainly applied by telecommunication operators in FTTH project. All these equipment are provided in TARLUZ and have the characteristic of high integration, flexible adaption, reliability Today’s topic is over. Do you have any questions? Please leave your comment. For more info, please browse our website.
