Application of Fiber Optic Cross Connection Cabinet(OCC)

The diversity of optical access networks in terms of structure, hierarchy, and user distribution of fiber access networks?determines that there are many structural forms of OCC. According to the structural relationship between splicing?and termination, it can be divided into splicing?separation and splicing?integration. According to the installation position in the transmission network hierarchy, it can be divided into trunk layer, distribution layer, and access layer OCC. In addition, it can be classified by capacity, installation method, etc. Currently, the most popular classification is based on the mode of patch cord jumping. One is the OCC that uses patch cord?to connect and route the terminals; the other is the free-patch cord?OCC with direct connection between part of the modules (the module may be an integrated tray or pigtail type?splitter) and another part of the modules. In this article, they are referred to as OCC and free-jump fiber OCC respectively.

Function and Application of OCC

OCC products have appeared very early, and they have appeared since the early stage of optical network construction. It is derived from the concept of optical distribution?frame?in the equipment?room, but it is different from the distribution frame. It provides optical cable termination, distribution, and cross-connection for trunk layer optical cables and distribution layer optical cables. The working performance is that after the optical cable is introduced into the OCC, after fixing, splicing, fiber distribution and termination, the patch cord?is used to connect and route the trunk layer optical cable and the distribution layer optical cable. The?cable resources can be flexibly configured according to user needs and are easy to manage.

The?without patchcord?OCC was introduced with the construction of FTTx (optical fiber access). In essence, it is an end-shaped product. Its principle is completely transplanted from the early function of a single-function distribution frame. The function is to divide the cable. It is mainly suitable for optical fiber distribution in FTTH mode, PON technology access close to the user terminal.

In summary, OCC can be applied to trunk optical nodes FP (optical flexible point), distribution optical nodes DP (optical distribution point), and user optical nodes. It is suitable for ring network structure, as well as tree and star network structure. Due to the over-specific definition of the structure, the application of the without patchcord?OCC as a terminal product is generally limited to user optical nodes and a small number of distribution optical nodes DP with lower?requirements. It is suitable for star and tree network structures.

In order to ensure the rationality of scheduling and the convenience of resource management in business operation, it is necessary to pay attention to the adaptability of the structure and business type of OCC in the construction, and it is advisable to build them separately.

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OCC Fiber Allocation and Networking Principles

Considering that the trunk optical node has a flexible scheduling function for the fiber cores of the distribution optical cable, the trunk optical node should make appropriate convergence for the number of fiber cores of the distribution optical cable. According to engineering experience and relevant guidance opinions, the ratio of the number of trunk fibers configured at the trunk optical node to the capacity?of distribution fibers is usually around 1:1.2?times. In addition, for the trunk optical node of the OLT (optical line terminal) node, the capacity?of trunk fibers configured should consider the convergence of OLT to PON access users, and a higher proportion of convergence should be made.

The trunk optical cable is the aggregation layer for user business access. Its network security is of vital importance. It should be used in a ring network structure as much as possible, with a tree structure as an auxiliary. In addition, when planning, the trunk optical cable is generally not deliberately formed into a ring, but is formed into a ring in the case of fixed routing conditions. It is recommended to use a ring non-decreasing shared fiber + exclusive fiber + reserved fiber for the fiber allocation of ring structure optical cable. The tree structure optical cable should also be fibered in a non-decreasing manner, and when the routing conditions are available in the future, it can be formed into a ring.

When choosing the location of the OCC, it should be combined with the city?road planning and various development community planning, avoiding roads that may be renovated in the near future. The optical cable route should also pass through the business-intensive area as close as possible.

Application Scenarios of the without patchcord OCC

The without patchcord?OCC is generally set at the optical cable leading-in?layer. The location is in residential communities, near residential buildings. In the FTTH access mode, it is set at the optical distribution concentration point. In the multi-level?optical division mode, it is often set at the first-level division point position. Since its structural flexibility is weak and the logical network is difficult to form a ring, Therefore, this type of fiber optic cross connection cabinet is not suitable for use as a backbone fiber optic cross connection cabinet.