Under the new service mode, the traditional LAN has more and more obvious disadvantages, such as poor stability of network performance, complex network structure, large space occupation, difficult maintenance, short coverage distance, etc. In the face of the above problems, the current PON based LAN networking scheme, namely the passive optical LAN mode, can well meet the challenges brought by new services
Challenges of Pol network to cabling
Pol network structure is a standard tree structure, and its deployment mode is flexible. In order to fully highlight its high bandwidth and multi service carrying capacity, the optical fiber is usually deployed to the desktop or near the desktop as much as possible. Compared with the traditional network wiring construction, such deployment will bring some challenges, mainly in the following two aspects:
1. Change of construction object
Different from the traditional network, all cables in the trunk, horizontal and even working areas of Pol network are optical cables. The laying and connecting methods of optical cables are quite different from those of traditional copper cables, especially the stripping and welding of optical cables often require professional construction technicians. These changes bring difficulties and adjustments to the traditional construction.
2. Deployment of ONU
Most of the solutions will use the way of deploying ONU near the desktop, which will cause a large number of open lines on the desktop, which will affect the cleanliness and beauty of the user's work area, and is not convenient to use
System diagram of Pol pre termination scheme
The system is mainly composed of pre terminated distribution frame, pre terminated trunk, pre terminated fiber distribution box and pre terminated horizontal cable. The pre terminated distribution frame and the pre terminated distribution box are connected with the pre terminated trunk. The pre terminated distribution box can lead out pre terminated horizontal cables, and the horizontal cables are directly connected to ONU.
MPO multi-core connector is used for the pre termination of trunk part, and SC movable connector is used for pre termination of horizontal cable. The nodes connecting the trunk cable and the horizontal cable are transferred by the module box built in the fiber distribution box. In order to protect the pre terminated connector, a specially designed protective sleeve is designed at the joint of the main optical cable to avoid damaging the connector in the process of dragging construction, resulting in excessive cable insertion loss. In addition, a branching device structure is designed for the main branch part, which can be installed in the branching box to anchor the whole trunk optical cable in the splitter box. The use of branching device can avoid the side pressure of the main cable when it is fixed, and ensure the original state of the optical fiber in the cable sleeve, so as to avoid the optical loss caused by external force. All cables in the pre termination system are of fixed length, which requires that the approximate length of cables should be calculated before construction, otherwise, the cable may be wasted or insufficient.
