Editing Wi-Fi (section)

== Hardware ==
[[File:RouterBoard 112 with U.FL-RSMA pigtail and R52 miniPCI Wi-Fi card.jpg|thumb|An [[embedded system|embedded]] [[MikroTik#RouterBOARD|RouterBoard]] 112 with [[U.FL]]-[[SMA connector|RSMA]] pigtail and R52 [[Conventional PCI|mini PCI]] Wi-Fi card widely used by [[wireless]] Internet service providers ([[Wireless Internet service provider|WISPs]]) in the [[Czech Republic]]]]
[[File:3GN.jpg|thumb|OSBRiDGE 3GN – [[IEEE 802.11n-2009|802.11n]] access point and [[High-Speed Downlink Packet Access|UMTS/GSM]] gateway in one device]]

Wi-Fi allows wireless deployment of local area networks (LANs). Also, spaces where cables cannot be run, such as outdoor areas and historical buildings, can host wireless LANs. However, building walls of certain materials, such as stone with high metal content, can block Wi-Fi signals.

A Wi-Fi device is a [[Short-range device|short-range]] [[wireless]] device. Wi-Fi devices are [[semiconductor device fabrication|fabricated]] on [[RF CMOS]] [[integrated circuit]] ([[RF circuit]]) chips.<ref>{{cite book |last1=Veendrick |first1=Harry J. M. |title=Nanometer CMOS ICs: From Basics to ASICs |date=2017 |publisher=Springer |isbn=9783319475974 |page=243 |url=https://books.google.com/books?id=Lv_EDgAAQBAJ&pg=PA243 |access-date=26 October 2019 |archive-date=17 January 2023 |archive-url=https://web.archive.org/web/20230117221755/https://books.google.com/books?id=Lv_EDgAAQBAJ&pg=PA243 |url-status=live }}</ref>

Since the early 2000s, manufacturers are building wireless network adapters into most laptops. The price of [[chipset]]s for Wi-Fi continues to drop, making it an economical networking option included in ever more devices.<ref>{{cite web|url=https://www.thedigitalworm.com/free-wifi-analyzer-apps/|title=Free WiFi Analyzer-Best Channel Analyzer Apps For Wireless Networks|date=8 June 2017|website=The Digital Worm|archive-url=https://web.archive.org/web/20170808000116/https://www.thedigitalworm.com/free-wifi-analyzer-apps/|archive-date=8 August 2017|url-status=usurped}}</ref>

Different competitive brands of access points and client network-interfaces can inter-operate at a basic level of service. Products designated as "Wi-Fi Certified" by the Wi-Fi Alliance are [[backward compatible]]. Unlike [[mobile phone]]s, any standard Wi-Fi device works anywhere in the world.

=== Access point ===
[[File:Apple-Airport-Extreme-80211g-WiFi-Card.jpg|thumb|upright|An [[AirPort]] Wi‑Fi adapter, supporting 802.11g, from an Apple [[MacBook]]]]

A wireless access point (WAP) connects a group of wireless devices to an adjacent wired LAN. An access point resembles a [[Ethernet hub|network hub]], relaying [[data (computing)|data]] between connected wireless devices in addition to a (usually) single connected wired device, most often an Ethernet hub or switch, allowing wireless devices to communicate with other wired devices.

=== Wireless adapter ===
[[File:Wireless network interface controller Gigabyte GC-WB867D-I - front and back - 2018-05-15.jpg|thumb|Wireless network interface controller Gigabyte GC-WB867D-I]]

Wireless adapters allow devices to connect to a wireless network. These adapters connect to devices using various external or internal interconnects such as mini PCIe ([[mPCIe]], [[M.2]]), USB, [[ExpressCard]] and previously PCI, Cardbus, and [[PC Card]]. As of 2010, most newer laptop computers come equipped with built-in internal adapters.

=== Router ===
[[Wireless router]]s integrate a Wireless Access Point, Ethernet [[Network switch|switch]], and internal router firmware application that provides [[Internet Protocol|IP]] [[routing]], [[Network address translation|NAT]], and [[DNS]] forwarding through an integrated WAN-interface. A wireless router allows wired and wireless Ethernet LAN devices to connect to a (usually) single WAN device such as a cable modem, [[DSL modem]], or [[optical modem]]. A wireless router allows all three devices, mainly the access point and router, to be configured through one central utility. This utility is usually an integrated [[web server]] that is accessible to wired and wireless LAN clients and often optionally to WAN clients. This utility may also be an application that is run on a computer, as is the case with as Apple's AirPort, which is managed with the [[AirPort Utility]] on [[macOS]] and iOS.<ref>{{cite web|url=https://www.apple.com/airportextreme/features/utility.html|title=Apple.com Airport Utility Product Page|publisher=Apple, Inc.|access-date=14 June 2011|url-status=live|archive-url=https://web.archive.org/web/20110608183330/http://www.apple.com/airportextreme/features/utility.html|archive-date=8 June 2011}}</ref>

=== Bridge ===
Wireless [[network bridge]]s can act to connect two networks to form a single network at the [[OSI model#Layer 2: Data link layer|data-link layer]] over Wi-Fi. The main standard is the [[wireless distribution system]] (WDS).

Wireless bridging can connect a wired network to a wireless network. A bridge differs from an access point: an access point typically connects wireless devices to one wired network. Two wireless bridge devices may be used to connect two wired networks over a wireless link, useful in situations where a wired connection may be unavailable, such as between two separate homes or for devices that have no wireless networking capability (but have wired networking capability), such as [[Consumer electronics|consumer entertainment devices]]; alternatively, a wireless bridge can be used to enable a device that supports a wired connection to operate at a wireless networking standard that is faster than supported by the wireless network connectivity feature (external dongle or inbuilt) supported by the device (e.g., enabling Wireless-N speeds (up to the maximum supported speed on the wired Ethernet port on both the bridge and connected devices including the wireless access point) for a device that only supports Wireless-G).
A dual-band wireless bridge can also be used to enable 5&nbsp;GHz wireless network operation on a device that only supports 2.4&nbsp;GHz wireless and has a wired Ethernet port.

=== Repeater ===
Wireless range-extenders or [[wireless repeater]]s can extend the range of an existing wireless network. Strategically placed range-extenders can elongate a signal area or allow for the signal area to reach around barriers such as those pertaining in L-shaped corridors. Wireless devices connected through repeaters suffer from an increased latency for each hop, and there may be a reduction in the maximum available data throughput. Besides, the effect of additional users using a network employing wireless range-extenders is to consume the available bandwidth faster than would be the case whereby a single user migrates around a network employing extenders. For this reason, wireless range-extenders work best in networks supporting low traffic throughput requirements, such as for cases whereby a single user with a Wi-Fi-equipped tablet migrates around the combined extended and non-extended portions of the total connected network. Also, a wireless device connected to any of the repeaters in the chain has data throughput limited by the "weakest link" in the chain between the connection origin and connection end. Networks using wireless extenders are more prone to degradation from interference from neighbouring access points that border portions of the extended network and that happen to occupy the same channel as the extended network.

=== Embedded systems ===
[[File:Ezurio wism2 small.jpg|thumb|Embedded serial-to-Wi-Fi module]]

The security standard, [[Wi-Fi Protected Setup]], allows embedded devices with a limited graphical user interface to connect to the Internet with ease. Wi-Fi Protected Setup has 2 configurations: The Push Button configuration and the PIN configuration. These embedded devices are also called The [[Internet of things]] and are low-power, battery-operated embedded systems. Several Wi-Fi manufacturers design chips and modules for embedded Wi-Fi, such as GainSpan.<ref>{{cite web
|url=http://www.gainspan.com/technology/technology_overview.php
|title=GainSpan low-power, embedded Wi-Fi
|publisher=www.gainspan.com
|access-date=17 June 2017
|archive-url=https://web.archive.org/web/20100630050952/http://www.gainspan.com/technology/technology_overview.php
|archive-date=30 June 2010
|url-status=dead
}}</ref>

Increasingly in the last few years (particularly {{As of| 2007 | lc=on}}), embedded Wi-Fi modules have become available that incorporate a real-time operating system and provide a simple means of wirelessly enabling any device that can communicate via a serial port.<ref>{{cite web
 |url         = http://edageek.com/2008/04/18/embedded-wifi-radio/
 |title       = Quatech Rolls Out Airborne Embedded 802.11 Radio for M2M Market
 |access-date  = 29 April 2008
 |url-status  = live
 |archive-url  = https://web.archive.org/web/20080428103306/http://edageek.com/2008/04/18/embedded-wifi-radio/
 |archive-date = 28 April 2008
}}</ref> This allows the design of simple monitoring devices. An example is a portable ECG device monitoring a patient at home. This Wi-Fi-enabled device can communicate via the Internet.<ref>{{cite web
 |url         = http://wifiscan.fr/research/article_19742.htm
 |title       = CIE article on embedded Wi-Fi for M2M applications
 |access-date  = 28 November 2014
 |url-status     = dead
 |archive-url  = https://web.archive.org/web/20150418040305/http://wifiscan.fr/research/article_19742.htm
 |archive-date = 18 April 2015
}}</ref>

These Wi-Fi modules are designed by [[OEM]]s so that implementers need only minimal Wi-Fi knowledge to provide Wi-Fi connectivity for their products.

In June 2014, [[Texas Instruments]] introduced the first ARM Cortex-M4 microcontroller with an onboard dedicated Wi-Fi MCU, the SimpleLink CC3200. It makes embedded systems with Wi-Fi connectivity possible to build as single-chip devices, which reduces their cost and minimum size, making it more practical to build wireless-networked controllers into inexpensive ordinary objects.<ref>{{Cite web|url=https://www.macinstallations.com/wifi-connectivity-explained/|title=Wifi Connectivity Explained {{!}} MAC Installations & Consulting|language=en-US|access-date=9 February 2020|archive-date=5 May 2020|archive-url=https://web.archive.org/web/20200505091852/https://www.macinstallations.com/wifi-connectivity-explained/|url-status=live}}</ref>