Kenneth C. Laudon,Jane P. Laudon Management Information System 12th Edition pdf

Wide area networks (WANs)

span broad geographical distances—entire

regions, states, continents, or the entire globe. The most universal and powerful

WAN is the Internet. Computers connect to a WAN through public networks,

such as the telephone system or private cable systems, or through leased lines

or satellites. A 

metropolitan area network (MAN)

is a network that spans a

metropolitan area, usually a city and its major suburbs. Its geographic scope

falls between a WAN and a LAN.

---

Chapter 7

Telecommunications, the Internet, and Wireless Technology

255

PHYSICAL TRANSMISSION MEDIA

Networks use different kinds of physical transmission media, including twisted

wire, coaxial cable, fiber optics, and media for wireless transmission. Each has

advantages and limitations. A wide range of speeds is possible for any given

medium depending on the software and hardware configuration.

Tw i s t e d   W i r e

Twisted wire

consists of strands of copper wire twisted in pairs and is an older

type of transmission medium. Many of the telephone systems in buildings had

twisted wires installed for analog communication, but they can be used for

digital communication as well. Although an older physical transmission

medium, the twisted wires used in today’s LANs, such as CAT5, can obtain

speeds up to 1 Gbps. Twisted-pair cabling is limited to a maximum recom-

mended run of 100 meters (328 feet).

C o a x i a l   C a b l e

Coaxial cable

, similar to that used for cable television, consists of thickly

insulated copper wire that can transmit a larger volume of data than twisted

wire. Cable was used in early LANs and is still used today for longer (more than

100 meters) runs in large buildings. Coaxial has speeds up to 1 Gbps. 

F i b e r   O p t i c s   a n d   O p t i c a l   N e t w o r k s