Attenuation reduces sn with cable length which

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Unformatted text preview: tenuation reduces S/N with cable length, which reduces capacity. But there is another factor that reduces capacity further: Higher frequencies generally attenuate more than low frequencies, which reduces the usable bandwidth. T wisted Pair - a pair of wires twisted together to reduce electromagnetic coupling. Common situation: four twisted pairs in a plastic sheath. Often pre wired for 4 telephone connections. Category 3 - fewer twists per centimeter Category 5 - more twists per centimeter Shielded twisted pair (STP) - metallic sheathing around the pair High rates - even 100 Megabits/second possible for short distances, but high attenuation at high frequencies greatly reduces capacity with length. Coaxial cable Insert Figure 2-4 Coaxial cable supplies much higher data rates over long distance than twisted pair. Signaling at frequencies up to 500 mhz is feasible up to about a kilometer distance. Applications Television distribution Long distance telephone Short computer system links Local area networks Optical Fiber Show Figure 2-7 Glass core is 50 microns, or in single mode fiber, 8-10 microns. Text says...
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This document was uploaded on 04/03/2014 for the course EE 362 at Pennsylvania State University, University Park.

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