Chapter 7 – Wireless Technologies
WIRELESS TECHNOLOGIES – includes both wireless devices and smartphones.
Wireless Devices – wireless devices help make productive use of time. The Wireless
Application Protocol (WAP) is the standard that enables wireless devices to access the
internet. Previously had micro browsers but now have full-function browsers. They are small to
carry and have sufficient computing power. However, they can be used to pass on confidential
Wireless Transmission Media – broadcasts media without wires over the air or in space such
as microwave, satellite, radio and infrared.
• Microwave transmission – used for high-volume, long-distance, line-of-sight
communication. They have high bandwidth and relatively inexpensive but must have
unobstructed line of sight
• Satellite – satellite transmission make use of communication satellites. Three types are:
Geostationary (GEO), medium earth orbit (MEO), and low earth orbit (LEO). They work
with lines of sight as well but the footprint is enormous since the higher the satellite, the
larger the footprint. They use broadcast transmission and have high bandwidth.
o Global positioning system – a wireless system that uses satellites for users to
determine their position anywhere on earth. GPS is supported by 24 MEO
satellites that are shared worldwide.
o Internet over Satellite (IoS) – allows users to connect to the internet via GEO
satellites but may entail a propagation delay.
• Radio Transmission – radio-wave frequencies to send data directly between transmitters
and receivers. The waves can travel through walls and are fairly inexpensive to install.
But it can create interference problems and can be intercepted.
o Satellite radio – satellite radio offers uninterrupted quality transmission beamed
to the radio from space.
• Infrared Transmission – it is a red light not commonly visible to human eyes. Used in
remote controls etc. used for short-distance connections.
WIRELESS COMPUTER NETWORKS AND INTERNET ACCESS – wireless networks can be
arranged by their effective distance:
Short-Range Wireless Networks – to connect devices and eliminate wires. They work around
a range of 100 feet. • Bluetooth Networks – used to create personal area networks which can be used for
communication among computer devices.
• Ultra-Wideband Networks – UWB is a high-bandwidth wireless technology with
transmission speeds in excess of 100 Mbps. This is good for transmitting media from a
PC to a TV.
• Near-Field Communications Networks – NFC has the smallest range. It is embedded in
cellphone and credit cards.
Medium-Range Wireless Networks – these are WLANs and Wi-Fi networks.
• Wireless Fidelity (Wi-Fi) – a medium range, Wireless Local area network. A transmitter
called a wireless access point is connected to a wired LAN to provide internet access. A
hotspot is the area in which the Wi-Fi can provide service. Wi-Fi can be accessed
through smartphone and laptops. Most Wi-Fi networks work on the 802.11 standard and
have a range about 300 feet. It is low cost. However, users cannot roam from hotspot to
hotspot. Some Wi-Fi are free while others charge a fee.
• Wireless Mesh Networks – use multiple Wi-Fi networks to create a wide-area network.
These a fairly expensive to implement and are failing.
Wide-Area Wireless Networks – used for internet over a large geographical area. The network
usually operates over the licensed spectrum. The two categories are:
• Cellular Radio – cellular telephones use radio waves to provide two-way communication.
The communication is done via radio antennas called cells. The technology have several
o First Generation (1G) – uses analog signals and low bandwidth
o Second Generation (2G) – uses digital signals primarily for voice and data up to
o Third Generation (3G) – uses digital signals for voice. Also support web browsing
and instant messaging
o Fourth Generation (4G) – a network that operates on internet technology in
combination with other technologies such as Wi-Fi for increased speeds.
• Wireless Broadband or WiMAX – Worldwide Interoperability for Microwave Access has
an access range of up to 31 miles, compared to 300 feet for Wi-Fi and data transfer of
up to 75Mbps. It is secure and offers voice and video.
MOBILE COMPUTING AND MOBILE COMMERCE – mobile computing is a real-time wireless
connection between a mobile device and other computing environments. This is different from
other forms of computing since it offers mobility and broad reach. The two characteristics cr