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-{{otheruses}}
-'''Wireless communication''' is the transfer of ''information'' over a distance without the use of electrical conductors or "[[wire]]s".<ref>{{citeweb|title=Wireless Communication|url=http://www.sintef.no/content/page1____11881.aspx|publisher=sintef.no|accessdate=2008-03-16}}</ref> The distances involved may be short (a few meters as in television remote control) or very long (thousands or even millions of kilometers for radio communications). When the context is clear the term is often simply shortened to "wireless". Wireless communications is generally considered to be a branch of [[telecommunications]].
-It encompasses various types of fixed, mobile, and portable [[two way radio]]s, [[Mobile phone|cellular telephone]]s, [[Personal Digital Assistant|personal digital assistant]]s (PDAs), and [[wireless network]]ing. Other examples of ''wireless technology'' include [[Global Positioning System|GPS]] units, [[Garage door opener|garage door openers and or garage doors]], wireless [[Computer mouse|computer mice]], [[Computer keyboard|keyboard]]s and [[Headset (telephone/computer)|headsets]], [[satellite television]] and cordless [[telephone]]s.
-==Introduction to Wireless==
-[[Image:Handheld Maritime VHF 217x289.png|thumb|right|217px|Handheld wireless radios such as this Maritime VHF radio transceiver use electromagnetic waves to implement a form of wireless communications technology.]]
-Wireless operations permits services, such as long range communications, that are impossible or impractical to implement with the use of wires. The term is commonly used in the telecommunications industry to refer to telecommunications systems (e.g., radio transmitters and receivers, remote controls, computer networks, network terminals, etc.) which use some form of energy (e.g. [[radio frequency]] (RF), [[infrared]] light, [[laser]] light, visible light, acoustic energy, etc.) to transfer information without the use of wires.<ref name="FS1037C">{{citeweb|title=ATIS Telecom Glossary 2007|url=http://www.atis.org/tg2k/|publisher=atis.org|accessdate=2008-03-16}}</ref> Information is transferred in this manner over both short and long distances.
-==Wireless communication==
-{{Unreferenced|date=December 2006}}
-The term "wireless" has become a generic and all-encompassing word used to describe communications in which electromagnetic waves or RF (rather than some form of wire) carry a signal over part or the entire communication path. Common examples of wireless equipment in use today include:
-* Professional LMR (Land Mobile Radio) and SMR (Specialized Mobile Radio) typically used by business, industrial and Public Safety entities
-* Consumer Two Way Radio including FRS (Family Radio Service), GMRS (General Mobile Radio Service) and Citizens band ("CB") radios
-* The Amateur Radio Service (''Ham radio'')
-* Consumer and professional Marine VHF radios
-* Cellular telephones 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.
-* Satellite television: allows viewers in almost any location to select from hundreds of channels.
-Wireless networking (i.e. the various flavors of unlicensed 2.4 GHz WiFi devices) is used to meet a variety of needs. Perhaps the most common use is to connect laptop users who travel from location to location. Another common use is for mobile networks that connect via satellite. A wireless transmission method is a logical choice to network a LAN segment that must frequently change locations. The following situations justify the use of wireless technology:
-* To span a distance beyond the capabilities of typical cabling,
-* To avoid obstacles such as physical structures, EMI, or RFI,
-* To provide a backup communications link in case of normal network failure,
-* To link portable or temporary workstations,
-* To overcome situations where normal cabling is difficult or financially impractical, or
-* To remotely connect mobile users or networks.
-''Wireless communication'' may be via:
-* [[radio]] frequency communication,
-* [[microwave]] communication, for example long-range line-of-sight via highly directional antennas, or short-range communication, or
-* [[infrared]] (IR) short-range communication, for example from [[remote control]]s or via [[IRDA]],
-Applications may involve [[Point-to-point communication (telecommunications)|point-to-point communication]], [[Point-to-multipoint communication (telecommunications)|point-to-multipoint communication]], [[broadcasting]] , [[cellular network]]s and other [[wireless network]]s.
-The term "wireless" should not be confused with the term "[[cordless]]", which is generally used to refer to powered electrical or electronic devices that are able to operate from a portable power source (e.g., a battery pack) without any cable or ''cord'' to limit the mobility of the cordless device through a connection to the mains power supply. Some cordless devices, such as cordless telephones, are also wireless in the sense that information is transferred from the cordless telephone to the telephone's base unit via some type of wireless [[Link (telecommunications)|communications link]]. This has caused some disparity in the usage of the term "cordless", for example in [[Digital Enhanced Cordless Telecommunications]].
-In the last 50 years, wireless communications industry experienced drastic changes driven by many technology innovations.
-==History==
-{{Main|History of radio}}
-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", "wireless energy transfer", etc. regardless of the specific technology (e.g., [[radio]], [[infrared]], [[ultrasonic]], etc.) that is used to accomplish the operation.
-===Early wireless work===
-[[David E. Hughes]], eight years before Hertz's experiments, induced electromagnetic waves in a signaling system. Hughes transmitted Morse code by an [[Electromagnetic induction|induction]] apparatus. In [[1878]], Hughes's induction transmission method utilized a "clockwork transmitter" to transmit signals. In [[1885]], [[Thomas Alva Edison|T. A. Edison]] used a vibrator magnet for induction transmission. In 1888, Edison deploys a system of signaling on the Lehigh Valley Railroad. In 1891, Edison attains the wireless patent for this method using inductance ({{US patent|465971}}).
-In the history of wireless technology, the demonstration of the theory of [[electromagnetic wave]]s by [[Heinrich Rudolf Hertz]] in 1888 was important.<ref name="Story">{{cite book|last = Story| first = Alfred Thomas| title =  A story of wireless telegraphy| publisher = New York, D. Appleton and Co.| date =  1904}}</ref><ref name="katz">{{citeweb|title=Heinrich Rudolf Hertz|url=http://chem.ch.huji.ac.il/~eugeniik/history/hertz.htm|publisher=chem.ch.huji.ac.il|accessdate=2008-03-16}}</ref> The theory of electromagnetic waves were predicted from the research of [[James Clerk Maxwell]] and [[Michael Faraday]]. Hertz demonstrated that electromagnetic waves could be [[Transmission (telecommunications)|transmitted]] and caused to travel through space at straight lines and that they were able to be [[Receiver (radio)|received]] by an experimental apparatus.<ref name="Story"/><ref name="katz"/> The experiments were not followed up by Hertz and the practical applications of the wireless communication and remote control technology would be implemented by [[Nikola Tesla]].
-{{see|Invention of radio}}
-==The electromagnetic spectrum==
-Light, colours, AM and FM radio, and electronic devices make use of the electromagnetic spectrum. In the US the frequencies that are available for use for communication are treated as a public resource and are regulated by the [[Federal Communications Commission]]. This determines which frequency ranges can be used for what purpose and by whom. In the absence of such control or alternative arrangements such as a privatized electromagnetic spectrum, chaos might result if, for example, airlines didn't have specific frequencies to work under and an [[amateur radio]] operator was interfering with the pilot's ability to land an [[airplane]]. Wireless communication spans the spectrum from 9&nbsp;kHz to 300&nbsp;GHz. (Also see [[Spectrum management]])
-==Applications of wireless technology==
-===Security systems===
-Wireless technology may supplement or replace hard wired implementations in security systems for homes or office buildings.
-===Television remote control===
-Modern televisions use wireless (generally infrared) remote control units.
-Now we also use radio waves.
-=== Cellular telephony (phones and modems) ===
-Perhaps the best known example of wireless technology is the [[cellular telephone]] and [[cellular modem|modems]]. These instruments use radio waves to enable the operator to make phone calls from many locations world-wide. They can be used anywhere that there is a cellular telephone site to house the equipment that is required to transmit and receive the signal that is used to transfer both voice and data to and from these instruments.
-=== WiFi ===
-''Main Article: [[Wi-Fi]]''
-==Categories of wireless implementations, devices and standards==
-{{Wiktionary}}
-*[[Radio communication system]]
-*[[Broadcasting]]
-*[[Amateur radio]]
-*[[Communication radio]]
-*[[Cordless telephone|Cordless telephony]]:[[DECT]] (Digital Enhanced Cordless Telecommunications)
-*[[Cellular system]]s:[[0G]], [[1G]], [[2G]], [[3G]], [[4G|Beyond 3G (4G)]], [[5G|Future wireless]]
-*[[List of emerging technologies]]
-*[[Short-range]] point-to-point communication : [[Wireless microphone]]s, [[Remote control]]s, [[Infrared Data Association|IrDA]], [[RFID|RFID (Radio Frequency Identification)]], [[Wireless USB]], [[Dedicated Short Range Communications|DSRC (Dedicated Short Range Communications)]], [[EnOcean]], [[Near Field Communication]]
-*[[Wireless sensor network]]s : [[ZigBee]], [[EnOcean]]; [[Personal area network]]s, [[Bluetooth]], [[Ultra-wideband]] (UWB from [[WiMedia Alliance]]).
-*[[Wireless computer network]]s: [[Wireless Local Area Networks]] (WLAN), ([[IEEE 802.11]] branded as [[WiFi]] and [[HiperLAN]]), [[Wireless Metropolitan Area Network]]s (WMAN) and [[Broadband Fixed Access]] (BWA) ([[LMDS]], [[WiMAX]], [[WANKA]] and  [[HiperMAN]])
-==See also==
-{{wikibooks|Nets, Webs and the Information Infrastructure}}
-* [[Mobile]]
-* [[History of radio]], [[Timeline of radio]], [[Digital radio]], [[Radio resource management]] (RRM)
-* [[Wireless telegraphy]], [[Wireless campus]], [[Wireless energy transfer]], [[True wireless]],  [[Wireless security]]
-* [[Personal area network]], [[comparison of wireless data standards]], [[List of emerging technologies]]
-==References==
-{{reflist|2}}
-==External links==
-* {{Wikia|wireless|wireless}}
-* [http://www.sunmantechnology.com/resources_gls_wl.html Wireless Glossary]
-* {{US patent|1642420}}, S. Loewe, "''Wireless Receiving Apparatus''"
-* {{US patent|1754875}},  E. E. Clement, "''Radiophone desk set''"
-* [http://www.deveo.net/ Wireless Operators Database]
-[[Category:Wireless networking]]
-[[Category:History of radio]]
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-[[ko:무선 통신]]
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