Attenuation - Loss of Signal on Transfer Data
Written by Julianus Yu
Attenuation is loss of signal, it happens because as a signal travels through a cable, some of it doesn’t make it all the way to the end of the cable. The longer the cable, the more signal loss there will be. In fact, past a certain point, the data will no longer be transmitted properly because the signal loss will be too great.
High Speed Data Transfer Main Concern
Written by Julianus Yu
Electricity flowing through a cable is nothing more than electrons moving inside the cable and bumping into each other—sort of like dominoes falling. For a signal to be received properly by the receiver, enough electrons must make contact all the way through the cable from the sender to the receiver. As the frequency on a cable (and consequently the potential data rate) increases, a number of phenomena hinder the signal’s travel through the cable (and consequently the transfer of data). These phenomena are important not only to the person who has to authorize cable purchase but also to the person who tests and certifies the cable.
The Advantages of Fiber Optic Over Copper Cable
Written by Julianus Yu
This article compares the system performance of two Local Area Networks (LAN) backbones, one using Cat.5 UTP 100W Copper cable, and the other using 62.5/125 mm multi-mode fiber optic cable. Performance will be evaluated in the areas of bandwith, attenuation, electromagnetic immunity, size, weight, safety, and security. The fiber optic system will operate at a 1300-nanometer wavelength with a light-emitting diode (LED) source. System performance data for both mediums is derived from Commercial Building Telecommunication Cabling Standard, ANSI/TIA/EIA-568-A-1995.
NEC Flame Ratings Level Description
Written by Julianus Yu
Plenum
According to building engineers, construction contractors, and air-conditioning people, the plenum is the space between the false ceiling (a.k.a. drop-down ceiling) and the structural ceiling, when that space is used for air circulation, heating ventilation, and air conditioning (HVAC). Occasionally, the space between a false floor (such as a raised computerroom floor) and the structural floor is referred to as the plenum. Typically, the plenum is used for returning air to the HVAC equipment. Raised ceilings and floors are convenient spaces in which to run data and voice cable, but national code requires that plenum cable be used in plenum spaces. Be aware that some people use the word plenum too casually, referring to all ceiling and floor spaces, whether or not they are plenums. This can be expensive because plenum cables can cost more than twice their nonplenum equivalent.
Cable type rating hierarchy
Written by Julianus Yu
Whether you are a network engineer, cable installer, or network manager, a good understanding of the design and components of data cabling is important. Do you know what types of cable can be run above the ceiling? What do all those markings on the cable mean? Can you safely untwist a twisted-pair cable? What is the difference between shielded and unshielded twisted-pair cable? What is the difference between single-mode and multimode fiber-optic cable?
About Fiber Optic Part II
Written by Julianus Yu
Single-Mode Fiber-Optic Cable
Single-mode fiber (SMF, sometimes called monomode) optic cable is most commonly used by telephone companies and in data installations as backbone cable. Single-mode fiber-optic cable is not used as horizontal cable to connect computers to hubs. The light in a single-mode cable travels straight down the fiber and does not bounce off the surrounding cladding as it travels. Typical single-mode wavelengths are 1,310 and 1,550 nanometers. Before you install single-mode fiber-optic cable, make sure the equipment you are using supports it. The equipment that uses single-mode fiber typically uses lasers to transmit light through the cable because a laser is the only light source capable of inserting light into the very small (8- to 10-micron) core of a single-mode fiber.
About Fiber Optic Part I
Written by Julianus Yu
Fiber-optic cable uses a strand of glass or plastic to transmit data signals using light; the data is carried in light pulses. Unlike the transmission techniques used by its copper cousins, optical fibers are not electrical in nature. Plastic-core cable is easier to install and slightly cheaper than glass core, but plastic cannot carry data as far as glass. In addition, graded-index plastic optical fiber (POF) has yet to make a widespread appearance on the market, and the cost-to-bandwidth value proposition for POF
is poor and may doom it to obscurity.
About Screened Twisted Pair (ScTP) / FTP
Written by Julianus Yu
A recognized cable type in the ANSI/TIA/EIA-568-B Standard is screened twisted-pair (ScTP) cabling, a hybrid of STP and UTP cable. ScTP cable contains four pairs of 24 AWG, 100-ohm wire surrounded by a foil shield or wrapper and a drain wire for bonding purposes. ScTP is also sometimes called foil twisted-pair (FTP) cable because the foil shield surrounds all four conductors. ScTP cable is essentially STP cabling that does not shield the individual pairs; the shield may also be smaller than some varieties of STP cabling.
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Who is Julianus?
Julianus juli, Jakarta - Indonesia, Project Support - Office Network / Cabling System Infrastructure & Data Center. FREE consultation send me a quotation at - me@julianusjuli.info
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