Introduction to Wi-Fi Wireless Networking

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Wi-Fi has emerged as the single most popular wireless network protocol of the 21st century. While other wireless protocols work better in certain situations, Wi-Fi technology powers most home networks, many business local area networks and public hotspot networks

Some people erroneously label all kinds of wireless networking as “Wi-Fi” when in reality Wi-Fi is just one of many wireless technologies. See - Guide to Wireless Network Protocols.

History and Types of Wi-Fi

In the 1980s, a technology designed for wireless cash registers called WaveLAN was developed and shared with the Institute of Electrical and Electronics Engineers (IEEE) group responsible for networking standards, known as committee 802. This technology was further developed during the 1990s until the committee published standard 802.11 in 1997.

The initial form of Wi-Fi from that 1997 standard supported only 2 Mbps connections. This technology was not officially known as “Wi-Fi” from the beginning either; that term was coined only a few years as its popularity increased. An industry standards group has continued to evolve the standard ever since, generating a family of new versions of Wi-Fi called successively 802.11b, 802.11g, 802.11n, 802.11ac, and so on. Each of these related standards can communicate with each other, although newer versions offer better performance and more features.

Modes of Wi-Fi Network Operation

Wi-Fi Hardware

Wireless broadband routers commonly used in home networks serve (along with their other functions) as Wi-Fi access points. Similarly, public Wi-Fi hotspots utilize one or more access points installed inside the coverage area.

Small Wi-Fi radios and antennas are embedded inside smartphones, laptops, printers, and many consumer gadgets enabling them to function as network clients. Access points are configured with network names that clients can discover when scanning the area for available networks.

Wi-Fi Hotspots

Hotspots are a kind of infrastructure mode network designed for public or metered access to the Internet. Many hotspot access points utilize special software packages for managing user subscriptions and limiting Internet access accordingly.

Wi-Fi Network Protocols

Wi-Fi consists of a data link layer protocol that runs over any of several different physical later (PHY) links. The data layer supports a special Media Access Control (MAC) protocol that uses collision avoidance techniques (technically called Carrier Sense Multiple Access with Collision Avoidance or CSMA/CA to help handle many clients on the network communicating at once

Wi-Fi supports the concept of channels similar to those of televisions. Each Wi-Fi channel utilizes a specific frequency range within the larger signal bands (2.4 GHz or 5 GHz). This allows local networks in close physical proximity to communicate without interfering with each other. Wi-Fi protocols additionally test the quality of the signal between two devices and adjust the connection’s data rate down if needed to increase reliability. The necessary protocol logic is embedded in specialized device firmware pre-installed by the manufacturer.

Common Issues With Wi-Fi Networks

No technology is perfect, and Wi-Fi possesses its share of limitations. Common issues people face with Wi-Fi networks include:

  • Security - Network traffic sent across Wi-Fi networks passes through open air making it prone to snooping from malicious strangers. Several kinds of security technology have been added to Wi-Fi over the years to help address this problem, although some work better than others. More - Introduction to Wi-Fi Network Security
  • Health concerns - Some people claim that extensive exposure to wireless radio signals like those from Wi-Fi networks cause headaches, nausea and other physical issues. Many industry experts assure the public that Wi-Fi is safe, but controversy persists as claims one way or the other are difficult to prove. More - Wireless Networking and Your Health
  • Signal range - A basic Wi-Fi network with one wireless access point reaches at most only a few hundred feet (100m or less) in any direction. Expanding the range of a Wi-Fi network requires installing additional access points configured to communicate with each other, which becomes expensive and difficult to support, especially outdoors. As with other wireless protocols, signal interference (from other wireless devices, or from physical obstructions such as walls) can lower the effective range of Wi-Fi and its overall reliability. More - What Is the Typical Range of a Wi-Fi Network?