Wi-Fi

Wi-Fi
Name	Wi-Fi
Caption	The Wi-Fi Alliance logo, a certification mark for interoperable products.
Invented	1997 (first standard released)
Industry	Telecommunications, Computer networking
Related	IEEE 802.11, Wireless LAN, Ethernet

Wi-Fi is a family of wireless network protocols, based on the IEEE 802.11 family of standards, which are commonly used for local area networking of devices and Internet access. It allows electronic devices to connect to a wireless LAN (WLAN) network, typically in the 2.4 gigahertz and 5 gigahertz radio frequency bands. Developed and maintained by the Institute of Electrical and Electronics Engineers (IEEE) LAN/MAN Standards Committee, its commercialization and certification for interoperability is managed globally by the Wi-Fi Alliance.

Overview

Wi-Fi technology enables high-speed data transmission without the physical constraints of cables, revolutionizing how devices connect within homes, businesses, and public spaces. It operates by using a wireless access point, such as a router, which creates a local network, and client devices like smartphones, laptops, and smart TVs connect to it. The technology's proliferation was accelerated by its inclusion in consumer electronics following the release of the 802.11b standard, supported by major industry players including Apple Inc. with its AirPort product line. Public access points, known as hotspots, are now ubiquitous in venues like Starbucks, airports, and libraries, often provided by internet service providers or municipalities.

Technical specifications

The core specifications are defined under the IEEE 802.11 project, with amendments lettered such as 802.11a, 802.11b, and 802.11g. These standards specify the use of the ISM band and define protocols for media access control and physical layer operations. Key technical aspects include the use of orthogonal frequency-division multiplexing (OFDM) for efficient data transmission and multiple-input and multiple-output (MIMO) technology to increase capacity. Performance is measured in terms of data rates, which have evolved from 2 Mbit/s in the original standard to multiple gigabits per second in modern iterations like Wi-Fi 6, and range, which is influenced by frequency band, transmit power, and environmental obstacles.

Security

Early security protocols like Wired Equivalent Privacy (WEP) proved vulnerable to attacks, leading to the development of more robust standards. The Wi-Fi Protected Access (WPA) suite, mandated by the Wi-Fi Alliance for certification, introduced significant improvements. WPA2, based on the IEEE 802.11i amendment, implemented the strong Advanced Encryption Standard (AES), while WPA3 further enhanced security with features like Simultaneous Authentication of Equals (SAE). Common threats include wardriving, evil twin attacks, and vulnerabilities in the WPS protocol, necessitating ongoing vigilance from users and network administrators.

Applications and uses

Beyond basic Internet browsing, Wi-Fi is foundational for the Internet of Things (IoT), connecting devices like smart thermostats, security cameras, and voice assistants such as Amazon Alexa. It enables Voice over IP (VoIP) services like Skype, supports wireless display standards including Miracast, and is critical for enterprise mobility solutions. In retail and hospitality, it facilitates customer engagement and analytics, while in healthcare, it supports the use of mobile devices for patient care. Major events like the Olympic Games rely on dense, high-capacity deployments to serve attendees and global media.

Standards and evolution

The evolution from 802.11 to 802.11ax (marketed as Wi-Fi 6) represents a journey of increasing speed, efficiency, and capacity. Each generation, often branded by the Wi-Fi Alliance (e.g., Wi-Fi 4 for 802.11n), introduced key technologies: 802.11n brought MIMO, 802.11ac introduced wider channels in the 5 GHz band, and 802.11ax focuses on performance in crowded environments. Future developments, such as those in the IEEE 802.11be project (anticipated as Wi-Fi 7), aim for extremely high throughput and lower latency, targeting applications in augmented reality and industrial automation.

Deployment considerations

Effective deployment requires careful planning of access point placement to ensure coverage and performance, a process often aided by site survey tools. Network architects must choose appropriate frequencies—the 2.4 GHz band offers better range but more congestion from devices like Bluetooth and microwave ovens, while the 5 GHz and newer 6 GHz bands provide more channels and less interference. In large-scale deployments, such as on university campuses like Stanford University or in corporate headquarters, managed systems from vendors like Cisco Systems or Aruba Networks provide centralized control, security, and analytics.

Category:Computer networking Category:Wireless networking Category:IEEE standards