A complete set of communication cables and switching equipment that meets the requirements of relevant regulatory documents. It includes a set of cables and switching elements, and a methodology for their joint use, which allows you to create regular expandable communication structures in local networks for various purposes.
SCS is the physical basis of the building’s infrastructure, which makes it possible to bring together a multitude of network information services for various purposes into a single system like local area networks and telephone networks, security systems, video surveillance, etc. SCS is a hierarchical data cabling system mounted in a building or in a group of buildings, consisting of structural subsystems.
Types of Cables and Their Characteristics
When constructing SCS, twisted pair of copper cables are used today, which are data and voice cables. There are several types of twisted pair cables for protection against external interference:
STP (Shielded Twisted Pair):
This is a cable in which each twisted pair is surrounded by a screen of metal foil or mesh. The screen must be properly grounded. If the ground is not properly grounded, the screen starts to work as an antenna, creating additional interference.
UTP (Unshielded Twisted Pair):
Unshielded twisted pair is one or more pairs of twisted wires enclosed in a plastic sheath. Protection from interference is ensured by the fact that the wires in each pair are twisted symmetrically and evenly, and the twist step in each pair is different.
FTP (Foiled Twisted Pair):
The Foiled Twisted pair cable is a shielded twisted pair consisting of one or more twisted pairs of conductors placed in a single screen of laminated foil.
S-FTP (Screened Foiled Twisted Pair):
It is also known as S-STP (Screened Shielded Twisted Pair), which are cables with a common screen made of metal foil and wire braid.
PiMF (Pairs in Metal Foil), or ISTP (Individually Shielded Twisted Pair)
These are cables with individual shielding of twisted pairs and a common screen of tinned wire braid. For patch cords, flexible cables are used in which each conductor is made of stranded wire.
Optic Fiber Cables
An optical fiber is an optical dielectric waveguide designed to transmit a broadband optical signal over long distances. The standard optical fiber is made of high-quality quartz glass, which ensures the propagation of light signals. Each optical fiber consists of a core and a cladding with different refractive indices. The core along which the light signal propagates is made of optically denser material. When designating fibers, the core and cladding diameters are indicated through a fraction.
The fibers differ in the diameter of the core and the sheath, as well as in the profile of the refractive index of the core. For a multimode gradient fiber and a single-mode dispersion-biased fiber, the core refractive index depends on the radius. Such a more complex profile is made to improve technical characteristics or to achieve special fiber characteristics.
- MMF (multi-mode fiber)
- Single-mode SMF (single-mode fiber)
Multimode fibers are divided into step indexes (step-index multi-mode fiber) and gradient fibers (graded-index multimode fiber).
Single-mode fibers are subdivided into step-index single-mode fiber or standard fiber SF, dispersion-shifted single-mode fiber, and non-zero dispersed fiber NZDSF (non-zero dispersion-shifted single-mode fiber).
Each manufacturer is looking for its own ways to provide the cable with the required parameters like plastic materials of different compositions are used, the conductors of one pair are glued together, a cross-shaped separator is introduced into the cable, separating each pair from the others, etc.
There are cables with an internal terminal, which carries a mechanical load and helps to comply with the requirements for the permissible bending radius of the cable. These data and voice communication cables are especially suitable for laying connections between cabinets with servers and other active equipment.
Bottom Line
It is impossible to say unequivocally which cable is better and which is worse. Everything is determined by the specific problem being solved (network architecture and topology, the amount of budgetary funds, availability of requirements regarding network expandability in the future, etc.). If there are specific requirements for a deployable LAN, a wireless solution may be acceptable. In this case, information is transmitted over the air or using infrared rays.
