Wireless networks are those computer
networks that use electromagnetic waves instead of wires in order to carry
signals over the various parts of the network. Wireless networks which run over
other wireless networks often utilize the lower layer networks to provide
security and encryption. Stand-alone wireless networks either provide their own
security and encryption features or relies upon VPNs (Virtual Private Networks)
to provide those features. In many cases, multiple layers of security and
encryption may be desirable.
Need for Wireless Networks and their
Benefits
Wireless networks belong to the fastest
growing technological areas under telecommunications. The widespread adoption
and popularity of wireless communication systems is a result of its many advantages
over wired systems.
The need for wireless networks arose from
the merits of both mobility and cost savings. Costs are reduced because the
wiring installed is very little, if at all it is needed. The time needed to
deploy such networks is drastically lesser than that of wired networks.
A wireless solution is perfectly suited for
locations where cabling is prohibited, or wiring is difficult to install, such
as heritage buildings or in areas near rivers.
Types of Wireless Networks
Wireless networks are classified in various
ways. Some wireless networks are fixed, meaning that antennas do not move
frequently. Other wireless networks are mobile, meaning that the antenna can
move constantly. The major types are classified in the passages that follow, based
on their ranges and the technology used.
Wireless Personal Area Networks
(Wireless PAN)
In a wireless personal area network,
devices are interconnected within a small area like a room. The Bluetooth
protocol is an example of a radio technology that is used in short ranges,
usually of some meters. For example, Bluetooth is used to wirelessly connect a
headset to a PC or laptop.
The Infrared Data Association (IrDA)
specifies protocol standards for data transfer using infrared rays in Wireless
PANs.
Wireless Local Area Network (Wireless
LAN)
Wireless Local Area Network is the wireless
implementation of local area networks (LANs). Data is transmitted between
computers by using radio waves sent across areas like large homes, office areas
or schools. The wireless LAN protocols are standardized under the IEEE 802.11
series.
Wi-Fi, a standard for “wireless fidelity”
is widely used for networking personal computers and the Internet. The Wi-Fi
technology brand, which is owned by the Wi-Fi Alliance, is used to certify
products to establish interoperability between the products using IEEE 802.11
standards.
Wireless Metropolitan Area Network
(Wireless MAN)
Wireless Metropolitan Area Networks connect
several Wireless LANs together. The IEEE 802.16 Standard is used for compliant
implementations of Wireless MAN. WiMax, which stands for Worldwide
Interoperability for Microwave Access, is an example of such an implementation.
The coverage can reach up to a radius of over 30 miles around the WiMax tower.
MMDS (Multichannel Multipoint Distribution
Service) is a broadband wireless MAN technology that uses point-to-multipoint
transmission using Ultra High Frequency (UHF). Its range can reach up to 70
miles.
LMDS (Local Multipoint Distribution
Service) is another point-to-multipoint technology that uses microwaves and
reaches a shorter range of up to 5 miles from the base station.
Mobile Networks
The above three wireless networks, PAN, LAN
and WAN run on their own physical layer networks, utilizing anything from
antennas built into handlheld devices to large antennas mounted on towers.
However, some wireless data networks run over wireless voice networks, such as
mobile telephone networks. The key types of mobile networks that are used for
data exchange are outlined below:
- CDPD (Cellular Digital packet Data). This is a specification
that supports wireless connectivity to the Internet over cellular
telephone networks.
- HSCSD (High Speed Circuit Switched Data). This is a
specification for data transfer over GSM networks.
- GPRS (General Packet Radio Service).This is a radio service
designed to run on the Global Systems for Mobile (GSM), which is a global
standard for cellular communication.
- CDMA (Code Division Multiple Access).This refers to the several
protocols of the 2G and 3G wireless communications. The CDMA-2000 1xRTT, a
3G wireless technology based on the CDMA platform, is widely used in
cellular and data communication networks.
- HSDPA (High Speed Downlink Packet Access).This is an enhanced
3G mobile communication protocol that allows Universal Mobile
Telecommunications System (UMTS) networks to facilitate high data transfer
speeds.
- EVDO (Evolution-Data Optimized).This is a telecommunications
standard for using radio signals to transmit data for broadband Internet
access. With the help of both Code Division Multiple Access (CDMA) and
Time Division Multiple Access (TDMA) technologies, it maximizes data
exchange speeds.
- EDGE (Enhanced Data rates for GSM Evolution).This is a global
radio-based mobile data transfer standard that facilitates high speeds of
up to 384 Kbps in packet-switched mode.
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