ts. This is important in large cities where conduits are often stuffed and at capacity with older copper cabling. A university in downtown Boston wanted to connect two buildings by running fiber-optic cabling under a public street between its buildings. This was a problem because there was no space left in the existing underground conduit that was already filled with copper cabling. The university needed to get permission from the city's authorities to dig up the www.TechnicalPDF.com street to add a new conduit, and they had to pay for digging up the street in addition to the cost to lay a new conduit for the fiber-optic cabling between their two buildings. If the conduit had fiber cabling, it's likely that space would have been available because of fiber's smaller diameter. More Capacity than Copper Cabling A significant advantage of fiber-optic cabling is its enormous capacity compared to copper cabling and mobile services. Light signals on optical cabling pulse on and off at such high data rates that they are able to handle vastly greater amounts of information than any other media and the capacity can be multiplexed into wavelengths. See Table 1-3 for a comparison of copper and fiber optic cabling. Table 1-3 Summary of Fiber-Optical Cabling Compared to Copper Cabling Characteristic Fiber-Optical Cabling Copper Cabling Diameter Thin as a strand of hair Larger diameter-Needs more space in conduits Capacity Higher-Non-electrical Lower- pulses SO no Electromagnetic electromagnetic interference causes interference resistance to signals Weight Light Heavier Distance 80 to 120 kilometers 2.4 to 3.2 kilometers before (49 to 74.4 miles) (11/2 to 2 miles) amplification n needed Installation Higher labor cost Lower-Less skill costs required Maintenanc Lower-Less equipment Higher-More www.TechnicalPDF.com e costs needed to boost signals equipment to maintain Security High-Need to Low-Can attach a physically break cable; monitor without cutting eavesdroppi easy to detect cable Half duplex Half duplex-A separate Full duple