Broadband Coaxial Cable
Broadband coaxial cable, also called 75 -ohm cable, is quite a bit thicker, heavier, and stiffer than the baseband variety. It was once commonly used in LAN sand can still be found in some older installations. For LANs, baseband cable is now preferable since it is less expensive, easier to physically handle, and does not require attachment cables. Broadband cable, however, is quite common in cable television systems. As we saw earlier, cable television systems have recently been coupled with cable modems to provide residential users with Web access at rates of 10 Mbps or higher. With broadband coaxial cable, the transmitter shifts the digital signal to a specific frequency band, and the resulting analogue signal is sent from the transmitter to one or more receivers. Both baseband and broadband coaxial cable can be used as a guided shared medium. Specifically, a number of end systems can be connected directly to the cable, and all the end systems receive whatever anyone of the computers transmits.
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