Wireless communications are used in a variety of professions.
Although the mix of wireless technologies is continually expanding, the focus of this discussion is on wireless networks that allow users to be mobile. Wireless networks can be classified broadly as:
- Wireless Personal-Area Networks (WPAN) - Operates in the range of a few feet. Bluetooth or Wi-Fi Direct-enabled devices are used in WPANs.
- Wireless LANs (WLANs) - Operates in the range of a few hundred feet such as in a room, home, office, and even campus environment.
- Wireless Wide-Area Networks (WWANs) - Operates in the range of miles such as a metropolitan area, cellular hierarchy, or even on intercity links through microwave relays.
Click each component in the figure to display more information about the various wireless technologies available to connect devices to these wireless networks:
- Bluetooth - Originally an IEEE 802.15 WPAN standard that uses a device-pairing process to communicate over distances up to .05 mile (100m). Newer Bluetooth versions are standardized by the Bluetooth Special Interest Group (https://www.bluetooth.org/).
- Wi-Fi (wireless fidelity) - An IEEE 802.11 WLAN standard commonly deployed to provide network access to home and corporate users, to include data, voice and video traffic, to distances up to 300m (0.18 mile).
- WiMAX (Worldwide Interoperability for Microwave Access) - An IEEE 802.16 WWAN standard that provides wireless broadband access of up to 30 miles (50 km). WiMAX is an alternative to cable and DSL broadband connections. Mobility was added to WiMAX in 2005 and can now be used by service providers to provide cellular broadband.
- Cellular broadband - Consists of various corporate, national, and international organizations using service provider cellular access to provide mobile broadband network connectivity. First available with 2nd generation cell phones in 1991 (2G) with higher speeds becoming available in 2001 and 2006 as part of the third (3G) and fourth (4G) generations of mobile communication technology.
- Satellite broadband - Provides network access to remote sites through the use of a directional satellite dish that is aligned with a specific geostationary Earth orbit (GEO) satellite. It is usually more expensive and requires a clear line of sight.
There are many types of wireless technologies available. However, the focus of this chapter is on 802.11 WLANs.