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.
Now I would like to introduce the main passive products of FTTH:
OLT an equipment integrating L2/L3 switch function in GEPON system. In general, OLT 
equipment contains rack, CSM (Control and Switch Module), ELM (EPON Link Module, PON card), redundancy protection -48V DC power supply modules or one 110/220V AC power supply module, and fans. In these parts, PON card and power supply support Hot- swap while other module is built inside. The main function of OLT is to control the information float across the ODN, going both directions, while being located in a central office..
TL6002C meets China Telecom EPON standards. It contains one piece 2-PON OLT card and 
one piece NMS card inside. TL6002C works with TL6200 and TL300 series ONU and ODN, to establish a passive optic network. The whole system supports 2-PON, each PON port supports 32pcs ONU within 20KM (64 pcs ONU within 10KM). It supports 10 ~ 20km transmission distance at the base of high bandwidth, and supports full line speed L2/L3 transition capacity.
ONU converts optical signals transmitted via fiber to electrical signals. These electrical signals are then sent to individual subscribers. In general, there is a distance or other access network between ONU and end user’s premises.
Furthermore, ONU can send, aggregate and groom different types of data coming from the customer and send it upstream to the OLT. ONU could be connected by various methods and cable types, like twisted-pair copper wire, coaxial cable, optical fiber or Wi-Fi. TL6208 ONU is an Ethernet product, with four fixed 10/100BASE-TX ports. TL6208 works with central device OLT to implement integrated management, long-distance fault location and decrease maintenance workload.
Optical Network Terminal (ONT)
Actually, ONT is the same as ONU in essence. ONT is an ITU-T term, whereas ONU is an IEEE term. They both refer to the user side equipment in GPON system. But in practice, there is a little difference between ONT and ONU according to their location. ONT is generally on customer premises.
In the Fiber Optic network, generally cables are limited to have 2km or 3km per reel, thus it requires a device to extending the fiber cable in the long haul cable network, CATV HFC network, FTTH PON network, etc.
A traditional fiber optic splice closures with multiple ports for cable entry in and with ports for cable extending, distributing, branching, etc. inside the box body, there is space with fiber optic splice tray installed for holding, protecting and managing the fiber cable after cable been spliced. There are inline type, sometimes we say horizontal type fiber optic splice closures, and dome type or vertical type, butt type.
However, recently closures are with more function than cable protection and joint, but splitting, thus splitting type fiber optic splice closure is very popular now, all this joint closures are made 
of high strength plastic, with excellent waterproof, dust proof, features. Tarluz offered various of FOSC, please feel free to contact for more product information.
Optical Distribution Frame (ODF)
The ODF Optical Distribution Frame is a necessary part of the indoor optical cable management. 12 cores fusion splicing and distribution module plays the main role and its function is splicing, fiber storage and protection. A completed ODF unit will be with adapter, pigtail and accessories like splice 
protection sleeve, nylon tie, snake like tube, screw. Tarluz ODF-A series is flexible installation, convenient for operation and maintenance. Designed as a drawer. This could be pulled out and pushed easily.
FAT is a terminal box installed near the customer premises or multi dwelling buildings for splitting and distribution drop cable to customer house, This box is generally made of plastic or SMC, with small size, light weight, and neat optical fiber routing. The FAT fiber access terminal box support wall mounting, pole mounting, is an ideal device for FTTx/FTTH project.
Tarluz offers full line of Fiber Access Terminal, the box are made of plastic, SMC or metal, the box able to distribution or splitting fiber cable, the cable capacity start from 2, 4, 8 until to 32 fiber cores, with SC, FC, ST, LC fiber panel for supporting different adapters.
FAT01 FAT is a 2-Port FTTH terminal box, made of PC+ABS plastic, with 1 inlet ports and 2 outlet ports, can be installed with PLC splitter, suitable for indoor wall mounting or pole mounting applications.
It is available for the distribution and terminal connection for various kinds of optical fiber system, especially suitable for mini-network terminal distribution, in which the optical cables, patch cores or pigtails are connected.
An access terminal box includes a protective cover, a base, and a base plate, where the protective cover includes a cover plate and side walls that are disposed around the cover plate, the cover plate and the side walls form an open-mouthed box structure, the base is fastened inside the open-mouthed box structure of the protective
cover by using a first detachable structure, the base is fastened to the base plate by using a second detachable structure. The fiber optic terminal box which is installed on the wall provides the function to splice the fibers, fiber and pigtail and the connection between the fiber optical connectors.
Optical Distribution Network (ODN)
ODN, an integral part of the PON system, provides the optical transmission medium for the physical connection of the ONUs to the OLTs. Its reach is 20 km or farther. Within the ODN, fiber optic cables, fiber optic connectors, passive optical splitters, and auxiliary components collaborate with each other. The ODN specifically has five segments which are feeder fiber, optical distribution point, distribution fiber, optical access point, and drop fiber. The feeder fiber starts from the optical distribution frame (ODF) in the central office (CO) telecommunications room and ends at the optical distribution point for long-distance coverage. The distribution fiber from the optical distribution point to the optical access point distributes optical fibers for areas alongside it. The drop fiber connects the optical access point to terminals (ONTs), achieving optical fiber drop into user homes. In addition, the ODN is the very path essential to PON data transmission and its quality directly affects the performance, reliability, and scalability of the PON system.
Conclusion
There are different equipment in the PON system 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 and capable of providing QOS, web-management as well as flexible enlarging capacity. For more information, please contact us over cs01@tarluz.com.
This issue mainly talks about the equipment in the PON system. The next issue will introduce the types of optical cables and drop cable in the FTTH link.
Stay tuned.
