Trunk cabling Subsystem Based on Integrated Cabling Standards

The main Integrated Wiring function is to provide mutual connection between the telecom room, equipment room, Master end connection room and entrance equipment. Trunk wiring consists of trunk cable, intermediate cross-connection and main cross-connection, mechanical final connection, and soft wires or jumpers used for trunk cross-connection. Trunk cabling also includes cabling between buildings. Trunk cabling should be able to serve one or more planning cycles for building users, with each planning cycle being 3-10 years. During each planning cycle, network service requirements and changes should be able to be adapted without the installation of additional cables. The duration of the planning cycle should be based on the stability and development of the user institution.

1. Topology

(1) Star

The trunk wiring adopts a common Layered Star topology. Each horizontal cross connection in the telecommunications room is directly connected to the primary cross connection, or the middle cross connection is connected to the primary cross connection. There are no more than two levels of crossover in the trunk wiring. Starting from a horizontal cross-connection, only one cross-connection arrives at the master cross-connection. Therefore, the connection between any two horizontal cross connections is connected by up to three cross-connection devices. The trunk cabling crossover is located in the telecom room, with rooms or portal equipment. The connector and shard cannot be part of the trunk cable.

The star topology has high flexibility. Up to two levels of crossover connections can limit passive system signal deterioration and simplify operations when the cabling system moves, adds, and changes. Of course, this restriction does not apply to parks with a large number of buildings or a wide range of geographical areas, such as universities, industrial parks and residential areas.

(2) Non-star topology

By using an appropriate internal connection, electronic device, or adapter, the topology can also adapt to non-star configurations, such as ring, tree, or mesh.

2. Transmission Distance

(1) distance between a building and a building

The maximum supported distance depends on the network transmission rate and transmission media type. Maximum Transmission Distance of trunk cabling: the total length of trunk cabling, including trunk cabling, cables, and equipment cables.

(2) master cross-connection of the entry Device

In the calculation of the total distance of the trunk wiring, the distance between the entry device and the master cross-connection can be included. The length and type of media (including copper cable specifications) shall be recorded.

(3) cross join

In the main crossover connection, the length of the Jumper and the soft wire should not exceed 20 m.

(4) cable cabling for telecommunications equipment

A telecom device that is directly connected to a primary or cross-connected device can be connected by a cable of less than 30 mb.

3. cable selection

One or more transmission media can be identified due to the wide service and field range of the trunk cabling used. This Standard specifies the transmission medium used separately or in combination in the trunk wiring. The following media are confirmed:

● 100 ohm twisted pair wire (ANSI/TLA/TLA-568-B-2)

● 62.5/125 μM or 50/125 μM Multimode Optical Cable (ANSI/TLA/TLA-568-B.3)

● Single-Mode Optical Cable (ANSI/TLA/TLA-568-B.3)

The trunk cabling stipulated in this standard is applicable to a wide range of requirements of different users. You can select a suitable trunk cable based on network applications and data transmission needs. When selecting cables, consider the following factors:

● Flexibility in support of various services

● Effective life required for trunk cabling

● Network scale and number of users

Because commercial buildings have different requirements for telecom services over time and users, the plan for using trunk cabling in the future is subject to high uncertainty. However, similar services are generally classified into several categories, such as sound, display terminals, LAN and other connections, and the quantity required for each category is planned. In the future, when the service requirements are not specified, the worst case should be used to evaluate different trunk wiring schemes. The higher the uncertainty of network applications, the higher the flexibility of the trunk wiring system.

When a single cable type cannot meet all requirements, more than one transmission medium should be used in the trunk wiring, for example, twisted pair wires, multimode optical cables or single-mode optical cables.