Ethernet Signal Preservation In Factory-Terminated Patch Cords for Local Area Networks

ONE of the most commonly asked questions with the introduction of the TrueNet™ Structured Cabling System is,“Why do you only offer patch cords in certain lengths?” Specifically, those lengths are 4, 7, 10 and 15 feet.An electrical impulse takes the shape of a sine wave. A wave has two components: the amplitude and the frequency (frequency can also be called wavelength). The amplitude is the “height” of the wave. The frequency, or wavelength, is the number of peaks in a given timeframe (see Figure 2).And the simple answer is: certain patch cord lengths cause unacceptable signal reflection and distortion to...
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Ethernet Signal Preservation In Factory-Terminated Patch Cords for Local Area NetworksEthernet Signal PreservationIn Factory-Terminated Patch Cords for Local Area Networks.ONE of the most commonly An electrical impulse takes the shape of a sine wave. A wave asked questions with the has two components: the amplitude and the frequency introduction of the TrueNet™ (frequency can also be called wavelength). The amplitude is Structured Cabling System is, the “height” of the wave. The frequency, or wavelength, is“Why do you only offer patch cords in certain lengths?” the number of peaks in a given timeframe (see Figure 2).Specifically, those lengths are 4, 7, 10 and 15 feet. AmplitudeAnd the simple answer is: certain patch cord lengthscause unacceptable signal reflection and distortion toEthernet signals, leading to errors and poor networkthroughput. Factory-terminated 4, 7, 10 and 15 footTrueNet cords prevent this distortion, preserving theintegrity of 10/100Base-T Ethernet signals. WavelengthWhat is an Ethernet signal? Figure 2: Sine wave.The explanation of what an Ethernet signal is, is rathercomplex. In fact, in order to begin, it is first important to The illustration below (Figure 3) shows four differentunderstand the composition of an Ethernet signal. sine waves, each with the same amplitude, but having varying frequencies.An Ethernet signal is designed to mimic the binary languageof computers (ones and zeros), by creating a signal whichcan be sent over a distance. One of the binary signalingmethods that is easiest to understand is Morse code, wherea quick “dot” is one and a long “dash” is zero. Ethernetuses electrical impulses to create a signaling method whichalso can be interpreted as zeros or ones. The basic idea is tocreate a square wave, seen below (Figure 1), where theinstantaneous changes up and down are used in indicate theone or zero. Using electrons to create a signal that looks likea square wave is somewhat tricky, but here is the basic idea: Figure 3: Sine waves of varying frequencies. In order to create a signal that looks like a square wave, you need to create a signal which combines many frequencies together (see Figure 4). The key component to remember is that the square wave of an Ethernet signal is made of many different sine waves, each important to creating the shape of the square wave.Figure 1: The square wave of an Ethernet signal.KRONE: 800-775-KRONE www.kroneamericas.com www.truenet-system.com.No part of this document may be reproduced without permission ©2000 KRONE, Inc. + = Add sine waves of different frequencies together... And it starts to Add even more frequencies... look like aThe key component square wave!to remember is thatthe square wave ofan Ethernet signalis made of manydifferent sine waves,each importantto creating the shape Figure 4: The square wave of an Ethernet signal is made of many different sine waves combined together.of the square wave. The next important thing to understand is that Ethernet Ethernet signals and patch cords expects the size and shape of the square wave to fall within We pointed out that an Ethernet square wave is made up of a set of defined boundaries, so that the signal can be the sum of many sine waves. If anything should happen to properly interpreted. One example of these boundaries is the the energy in one or more of those sine waves as they travel rise and fall time, or the time that it takes to indicate a down the wire, the shape of the square wave can change. change in state (see Figure 5). If either of these parameters ...