Wireless

Wireless

Wireless is a term used to describe telecommunications in which electromagnetic waves (rather than some form of wire) carry the signal over part or all of the 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.

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

Wireless communication is the transfer of information over a distance without the use of electrical conductors or "wires". The distances involved may be short (a few meters as in television remote control) or long (thousands or millions of kilometers for radio communications). When the context is clear, the term is often shortened to "wireless". Wireless communication is generally considered to be a branch of telecommunications.

It encompasses various types of fixed, mobile, and portable two way radios, cellular telephones, personal digital assistants (PDAs), and wireless networking. Other examples of wireless technology include GPS units, garage door openers and or garage doors, wireless computer mice, keyboards and headsets, satellite television and cordless telephones.The term "Wireless" came into public use to refer to a radio receiver or transceiver (a dual purpose receiver and transmitter device), establishing its usage in the field of wireless telegraphy early on; now the term is used to describe modern wireless connections such as in cellular networks and wireless broadband Internet. It is also used in a general sense to refer to any type of operation that is implemented without the use of wires, such as "wireless remote control" or "wireless energy transfer", regardless of the specific technology (e.g. radio, infrared, ultrasonic) that is used to accomplish the operation.

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 network refers to any type of computer network that is wireless, and is commonly associated with a telecommunications network whose interconnections between nodes is implemented without the use of wires. Wireless telecommunications networks are generally implemented with some type of remote information transmission system that uses electromagnetic waves, such as radio waves, for the carrier and this implementation usually takes place at the physical level or "layer" of the network.

Wireless LAN

Wireless Local Area Network (WLAN) is a wireless alternative to a computer Local Area Network (LAN) that uses radio instead of wires to transmit data back and forth between computers in a small area such as a home, office, or school. Wireless LANs are standardized under the IEEE 802.11 series.

• Wi-Fi: Wi-Fi is a commonly used wireless network in computer systems to enable connection to the internet or other devices that have Wi-Fi functionalities. Wi-Fi networks broadcast radio waves that can be picked up by Wi-Fi receivers attached to different computers or mobile phones.
• Fixed Wireless Data: This implements point to point links between computers or networks at two locations, often using dedicated microwave or laser beams over line of sight paths. It is often used in cities to connect networks in two or more buildings without physically wiring the buildings together.

Wireless MAN

Wireless Metropolitan area networks are a type of wireless network that connects several Wireless LANs.

• WiMAX is the term used to refer to wireless MANs and is covered in IEEE 802.16d/802.16e

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