Note
Chapter 4 Wireless Technology
173
cellular technology
a technology based
on radio waves
connecting to desig-
nated areas referred
to as cells.
Wireless Personal Area Networks in July, 2004. Bluetooth suffers from the same
radio interference sources as other 802.11 devices, which are part of the ISM band.
Bluetooth will not interfere with 802.11b devices when operated in the same
area because they use different formats for confi guring data. In other words, a
wireless keyboard and mouse based on the Bluetooth standard will not interfere
with the operation of an 802.11b wireless network.
For the very latest information about the Bluetooth standard, always check
the Bluetooth organization Web site at
www.Bluetooth.com
and www.bluetooth.org.
The name “Wireless Personal Area Network (WPAN)” is often used in place of “piconet.”
Cellular Technology
Cellular technology is based on radio waves connecting to designated areas
referred to as cells. Rather than communicate directly by radio wave from one
cell to another, a remote device connects to a radio transmitter/receiver within its
cell. The radio transmitter/receiver communicates to remote cells via microwave
transmission or telephone lines. In the remote cell, the message is sent to a radio
transceiver/receiver. The radio transceiver/receiver sends, via radio waves, the
message to the remote device within its cell. See Figure 4-24.
Cellular technology is responsible for wireless telephone and telephone
technology. The same technology connects mobile and stationary computer
equipment. A text message can be transmitted to a pager by typing in a message
using a desktop computer. The message is sent over an Internet connection to a
mobile telephone switching offi ce. From there, radio microwaves transmit the
encoded message to the distant pager system. See Figure 4-25.
Cellular technology supports duplex communication using a device such as a
personal digital assistant or a palmtop confi gured for wireless radio services.
Figure 4-24.
Cellular technology
communications
system.
Each cell, or geographic
area, is equipped with a
radio transmitter/receiver
Remote devices
communicate
with radio
transmitter/receiver
within its cell
Cell
Each cell communicates
with other cells via
microwave transmission
or telephone lines