Traditional ODN Product Link Introduction

The full name of ODN is Optical Distribution Node, optical distribution node, that is, passive optical fiber infrastructure network. In FTTH, it mainly refers to the section from OLT (Optical Line Terminal) to ONT (Optical Network Terminal). Broadly speaking, as long as there is optical fiber There is ODN in the place of optical cable, such as base station backhaul, all-optical park, transmission network, and FTTx.

In FTTH, the typical distance of ODN is 5~10km, and the length of the optical cable is generally 1~4km. In order to extend the optical cable to the user's home, there are ODF, SSC, FDT, FAT, ATB, TB and other ODN node equipment.

Usually, it can be divided into OSP and ISP according to the perspective of engineering construction. OSP is outdoor engineering and ISP is indoor engineering.

According to the network coverage level, it can be divided into home pass and home connect. Home pass refers to the equipment room to the user access point, and home connect refers to the user access point to the ONT.

But why are there so many ODN devices?

This starts from the scene from the equipment room to the user's home. The actual scene is quite complicated. The optical cable will pass from the CO equipment room to the user's home. Scenes.

To deal with such a complex scene, ODN equipment with various functions is required, but its essence is to complete the connection and protection of optical cables.

In the equipment room, the ODF (Optical Distribution Frame) on the ground is usually used to realize the connection between devices, or the connection between devices and optical cables. When the installation space of the equipment room is limited and the equipment capacity requirements are not high, a 19-inch or 21-inch unit frame can be configured to be installed in a comprehensive cabinet or other main equipment cabinet, or a wall-mounted ODF can be selected, because the indoor environment is relatively Well, the protection level of ODF is not high, usually IP2X.

After the optical cable comes out of the ODF, it will pass through the outdoor underground, outdoor streets and outdoor poles & walls to complete the home pass coverage. In the outdoor underground, SSC (Spliting and Splicing Closure,) is usually used to continuously extend the optical cable, or diverge to other places. The outdoor underground installation method is buried, the environment is harsh, and the protection level of the equipment is relatively high, generally requiring IP68.

Outdoor streets usually use FDT (Fiber Distribution Terminal) to connect the feeder cable and distribution cable. FDT is often installed on the floor or on a pole. It needs to have the performance of resisting drastic weather changes and harsh working environments, and generally requires IP55.

When the optical cable enters the home through outdoor poles and walls, FAT (Fiber Access Terminal, fiber distribution box) or SSC is usually used to realize the continuous, fiber separation and distribution functions of the distribution optical cable and the home optical cable. Because it is an outdoor environment , the protection requirements are relatively high, usually requiring IP55 or IP65.

After the outdoor connection is completed, the optical cable will enter the high-rise or villa and other home scenarios. For example, in the high-rise scenario, the optical fiber connection, splitting and wiring are usually performed through FAT. FAT is usually installed on the wall. Because it is an indoor environment, the protection level is generally required to be IP43. After the leather cable enters the room, it is usually terminated on the optical fiber terminal box, which is convenient for the jumper to connect to the ONT.

In the villa scene, in order to distinguish the indoor and outdoor optical interfaces, a TB (Terminal Box) is usually installed at the villa mouth to connect with the indoor ATB (Access Terminal Box), the TB is installed on the outdoor wall, and the IP level is IP55 or IP65. The ATB is usually installed indoors on the wall or embedded in the wall, and the protection level requires IP4X, which completes the end-to-end connection from the OLT to the ONT.