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However analog signals are very vulnerable to

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more tone than a digital representation of the same voice. However, analog signals are very vulnerable to interference from outside forces and other waves which can cancel them out. Digital Network Signaling A digital signal is made up of on/off states. Unlike the smooth curve of an analog wave, the digital signal cuts on and off, like morse code. This happens to perfectly fit the type of communication inside a computer, which is made up of on/off states as well. Advantages and Disadvantages of Digital Signals Digital signals are much more reliable than analog signals because they are less vulnerable to interference and errors. However, digital equipment costs more and is much more complex. RANSMISSION MEDIA The means through which data is transformed from one place to another is called transmission or communication media. There are two categories of transmission media used in computer communications. BOUNDED/GUIDED MEDIA UNBOUNDED/UNGUIDED MEDIA 1. BOUNDED MEDIA:
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Bounded media are the physical links through which signals are confined to narrow path. These are also called guide media. Bounded media are made up o a external conductor (Usually Copper) bounded by jacket material. Bounded media are great for LABS because they offer high speed, good security and low cast. However, some time they cannot be used due distance communication. Three common types of bounded media are used of the data transmission. These are Coaxial Cable Twisted Pairs Cable Fiber Optics Cable COAXIAL CABLE: Coaxial cable gets its name because it contains two conductors that are parallel to each other. The center conductor in the cable is usually copper. The copper can be either a solid wire or stranded martial. Outside this central Conductor is a non-conductive material. It is usually white, plastic material used to separate the inner Conductor form the outer Conductor. The other Conductor is a fine mesh made from Copper. It is used to help shield the cable form EMI. Outside the copper mesh is the final protective cover. (as shown in Fig) The actual data travels through the center conductor in the cable. EMI interference is caught by outer copper mesh. There are Gauge is the measure of the cable thickness. It is measured by the Radio grade measurement, or RG number. The high the RG number, the thinner the central conductor core, the lower the number the thicker the core. Here the most common coaxial standards. 50-Ohm RG-7 or RG-11 : used with thick Ethernet. 50-Ohm RG-58 : used with thin Ethernet 75-Ohm RG-59 : used with cable television 93-Ohm RG-62 : used with ARCNET. CHARACTERISTICS OF COAXIAL CABLE Low cost Easy to install Up to 10Mbps capacity Medium immunity form EMI Medium of attenuation ADVANTAGES COAXIAL CABLE Inexpensive Easy to wire Easy to expand Moderate level of EMI immunity DISADVANTAGE COAXIAL CABLE Single cable failure can take down an entire network
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However analog signals are very vulnerable to interference...

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