What is a Mobile?
A cellular
phone is a portable telephone that does not use a wired connection. It connects
to wireless carrier network using radio waves.
Wireless phone system
Wireless operations permits services,
such as long range communications, that are impossible or impractical to
implement with the use of wires. Wireless telecommunications,
is the transfer of information between two or more points that are physically
not connected. Examples of wireless phone system are Cordless telephone,
Cellular telephone, Mobile telephone, Radio telephone etc.
Wireless is a term used to describe telecommunications in
which electromagnetic waves carry the signal over part or the entire
communication path. Some monitoring devices, such as intrusion alarms, employ
acoustic waves at frequencies above the range of human hearing; these are also
sometimes classified as wireless.
The first wireless transmitters went on the air in the
early 20th century using radiotelegraphy (Morse code). Later, as modulation made it possible to transmit voices
and music via wireless, the medium came to be called "radio." With
the advent of television, fax,
data communication, and the effective use of a larger portion of the spectrum,
the term "wireless" has been resurrected.
Common examples of wireless
equipment in use today include:
·
Cellular phones and pagers -- provide
connectivity for portable and mobile applications, both personal and business
·
Global
Positioning System (GPS)
-- allows drivers of cars and trucks, captains of boats and ships, and pilots
of aircraft to ascertain their location anywhere on earth
·
Cordless
computer peripherals -- the cordless
mouse is a common
example; keyboards and printers can also be linked to a computer via wireless
·
Cordless
telephone sets -- these are limited-range devices, not to be confused with cell
phones
·
Home-entertainment-system
control boxes -- the VCR control and the TV channel control are the most common
examples; some hi-fi sound systems and FM broadcast receivers also use this
technology
·
Remote
garage-door openers -- one of the oldest wireless devices in common use by
consumers; usually operates at radio frequencies
·
Two-way
radios -- this includes Amateur and Citizens Radio Service, as well as
business, marine, and military communications
·
Baby
monitors -- these devices are simplified radio transmitter/receiver units with
limited range
·
Satellite television -- allows viewers in almost
any location to select from hundreds of channels
·
Wireless LANs
or local area networks -- provide flexibility and reliability for business
computer users
Wireless technology is rapidly evolving, and is playing an
increasing role in the lives of people throughout the world. In addition,
ever-larger numbers of people are relying on the technology directly or
indirectly. (It has been suggested that wireless is overused in some
situations, creating a social nuisance.) More specialized and exotic examples
of wireless communications and control include:
·
Global
System for Mobile Communication (GSM)
-- a digital mobile telephone system used in Europe and other parts of the
world.
·
General
Packet Radio Service (GPRS)
-- a packet-based wireless communication service that provides continuous connection
to the Internet for mobile phone and computer users.
·
Enhanced
Data GSM Environment (EDGE)
-- a faster version of the Global System for Mobile (GSM) wireless service.
·
Universal
Mobile Telecommunications System (UMTS)
-- a broadband, packet-based system offering a consistent set of services to
mobile computer and phone users no matter where they are located in the world.
·
Wireless
Application Protocol (WAP)
-- a set of communication protocols to standardize the way that wireless
devices, such as cellular telephones and radio transceivers, can be used for
Internet access.
·
i-Mode -- the world's first "smart
phone" for Web browsing, first introduced in Japan; provides color and
video over telephone sets
Wireless can be divided into:
·
Fixed
wireless -- the
operation of wireless devices or systems in homes and offices, and in
particular, equipment connected to the Internet via specialized modems.
·
Mobile wireless -- the use of wireless
devices or systems aboard motorized, moving vehicles; examples include the
automotive cell phone and PCS (personal communications services).
·
Portable wireless -- the operation of
autonomous, battery-powered wireless devices or systems outside the office,
home, or vehicle; examples include handheld cell phones and PCS units.
·
IR wireless -- the use of devices that convey data
via IR (infrared) radiation; employed in certain limited-range communications
and control systems.
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