Development of cabling systems (computer, telephone, video-surveillance, alarm, etc.) and, particularly, transfer to digital data transmission resulted in the 1980-s in the integration of all these systems into a unified hierarchical system called Structured Connectivity Solution.

The main standards of SCS are the following:

•  American standard EIA / TIA 568 B;

•  European standard EN 50173;

•  International standard ISO 11801.

SCS consists of the following subsystems:

Work area subsystem:

The Work Area Subsystem ensures connection of information outlets to the equipment. This subsystem involves patch-cords, adapters and transmission devices.

Horizontal subsystem:

Horizontal subsystem includes informational outlets in the work area, floor distribution frames connected by information cables.

If twisted pair cables are shorter than 90 m (it is typical for most small offices), Horizontal subsystem can connect informational outlets of several floors.

There is a special extension of Horizontal subsystem called "Zone architecture" and used in "open" offices, in which the location of information outlets is to be regularly changed. In this case "flexible" lines are used to connect information outlets at work areas with a specially installed zone block.

Vertical subsystem:

SCS Vertical subsystem is designated to unite 2 or more Horizontal subsystems into a single joint system. Active network equipment is to be installed between Vertical and Horizontal subsystems.

Both twisted pair and fiber optics cables are used within the Vertical subsystem.

Equipment subsystem:

Equipment subsystem includes active network equipment (concentrators, switches, routers, transceivers, etc.) and connecting wires – patch-cords.

Campus backbone:

Campus backbone usually connects SCS in different buildings of one and the same organization. It includes backbone fiber optics and brass cables, external and internal cables connecting mechanism, electric charge protection mechanism, etc.

Administrative subsystem:

Administrative subsystem includes patch-cords, used on distribution fields to connect SCS lines and/or active equipment.