The selection of cables should be comprehensively considered according to system requirements, technical performance, and investment estimates. In the integrated wiring system, the type of cable used and the wiring structure (shielded cable, non-screened cable, optical cable, or they are used together) should be determined first. Cables usually consist of 2 to 1800 pairs. Large-pair cables are usually used in trunk cabling systems and are suitable for use in voice and low-rate data applications. They are the largest in trunk and horizontal (hub-to-desktop) cabling systems. The length is specified in the international standard ISO/IECIS11801. It should be noted that these maximum length restrictions apply to all media, but do not take into account the performance aspects due to the different cable types and protocol types used in the network. impact of differences. In practice, the maximum cable length will depend on the application of the system, the type of network and the quality of the cable.

In addition, the selection of cable types should be considered in combination with the application requirements of the wiring system. The Cat5e system can support the operation of Gigabit Ethernet, and the Cat5e systems of different manufacturers can be interoperable; the price of Cat6e is more expensive than that of Cat5e, but its bandwidth is expanded by 25%, and the transmission rate is significantly higher. Increase, the six types of systems are dedicated, the components of each manufacturer have their own unique design and performance indicators, the possibility of interoperability between components of different manufacturers is very small, and the indicators of the components are still under study; the use of six types of cables should be selected For the plug-in devices of the same grade and manufacturer, because the six categories are special parts, the products of various manufacturers cannot yet communicate with each other.

The selection of shielded and unshielded cables depends on the external electromagnetic interference. When the interference field strength is lower than 3V/m, protective measures are generally not considered. When the interference signal exceeds the standard amount, shielded cables can be selected. The price of shielded cables is 1.2 to 1.6 times that of unshielded cables. Therefore, shielded cables are suitable for areas with severe electromagnetic interference and places with high confidentiality requirements.

At the same time, the wiring system should not only take into account the current needs, but also properly take into account the future development, and cannot ignore the influence of external factors. Just like the foundation of a building, the basic role of the wiring system in the intelligent system determines that it cannot be changed in a short period of time once it is built, so the wiring system has a long life cycle - 15 to 25 years.