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

personal area networks (PANs)

. It links up

to eight devices within a 10-meter area using low-power, radio-based communi-

cation and can transmit up to 722 Kbps in the 2.4-GHz band. 

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Chapter 7

Telecommunications, the Internet, and Wireless Technology

277

Wireless phones, pagers, computers, printers, and computing devices using

Bluetooth communicate with each other and even operate each other without

direct user intervention (see Figure 7-15). For example, a person could direct a

notebook computer to send a document file wirelessly to a printer. Bluetooth

connects wireless keyboards and mice to PCs or cell phones to earpieces

without wires. Bluetooth has low-power requirements, making it appropriate

for battery-powered handheld computers, cell phones, or PDAs.

Although Bluetooth lends itself to personal networking, it has uses in large

corporations. For example, FedEx drivers use Bluetooth to transmit the delivery

data captured by their handheld PowerPad computers to cellular transmitters,

which forward the data to corporate computers. Drivers no longer need to

spend time docking their handheld units physically in the transmitters, and

Bluetooth has saved FedEx $20 million per year.

W i - F i   a n d   W i r e l e s s   I n t e r n e t   A c c e s s

The 802.11 set of standards for wireless LANs and wireless Internet access is

also known as 

Wi-Fi

. The first of these standards to be widely adopted was

802.11b, which can transmit up to 11 Mbps in the unlicensed 2.4-GHz band and

has an effective distance of 30 to 50 meters. The 802.11g standard can transmit

up to 54 Mbps in the 2.4-GHz range. 802.11n is capable of transmitting over 100

Mbps. Today’s PCs and netbooks have built-in support for Wi-Fi, as do the

iPhone, iPad, and other smartphones. 

In most Wi-Fi communication, wireless devices communicate with a wired

LAN using access points. An access point is a box consisting of a radio

receiver/transmitter and antennas that links to a wired network, router, or hub.

Mobile access points such as Virgin Mobile’s MiFi use the existing cellular net-

work to create Wi-Fi connections. 

FIGURE 7-15

A BLUETOOTH NETWORK (PAN)

Bluetooth enables a variety of devices, including cell phones, smartphones, wireless keyboards and

mice, PCs, and printers, to interact wirelessly with each other within a small 30-foot (10-meter) area.

In addition to the links shown, Bluetooth can be used to network similar devices to send data from

one PC to another, for example.

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Part Two

Information Technology Infrastructure

Figure 7-16 illustrates an 802.11 wireless LAN that connects a small number of

mobile devices to a larger wired LAN and to the Internet. Most wireless devices

are client machines. The servers that the mobile client stations need to use are on

the wired LAN. The access point controls the wireless stations and acts as a

bridge between the main wired LAN and the wireless LAN. (A bridge connects

two LANs based on different technologies.) The access point also controls the

wireless stations. 

The most popular use for Wi-Fi today is for high-speed wireless Internet

service. In this instance, the access point plugs into an Internet connection,

which could come from a cable TV line or DSL telephone service. Computers

within range of the access point use it to link wirelessly to the Internet.