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It’s no surprise that the IEEE 802.11x wireless-local-area-network (WLAN) standards are commonly referred to as "alphabet soup." With over 35 lettered standards ranging from IEEE 802.11a to 802.11ak—each differentiated by only a few letters—it’s easy to be left perplexed by the nomenclature. The relative traffic of WLAN networks is increasing with new frequency bands, throughput rates, data streams, the proliferation of personal electronic devices, and industrial/commercial uses. Standards range from general maintenance to a China millimeter-wave standard. The key thing to understand is that the IEEE 802.11 Working Group of the IEEE Standards Association is dealing with a rapidly growing, expanding, and evolving wireless world with new demands and technological breakthroughs. To keep up with this fast-paced evolution, the working group convenes regularly to generate improvements, updates, and even forecast the future of WLAN.

Several standards designations are left out to limit confusion, amended out of the general pool of standards, or limited to recommendations (as opposed to official standards). To reduce confusion, the working group decided to not label any standard or task group with an ending of l, o, q, x, ab, or ag. The designations F and T were either withdrawn or cancelled, respectively, and remain merely as recommended practices.

The original standard, IEEE 802.11-1997, only supported one stream of 1 to 2 Mb/s throughput at 2.4 GHz with approximate indoor range of 20 m and outdoor range of 100 m. It has since been supplanted by the IEEE 802.11-2007 amendments, which brought together the standard designations a, b, d, e, g, h, i, and j. In the summer of 2007, those amendments were finalized by REVma or IEEE 802.11ma, which was developed by the maintenance task group TGma.

The amendment release IEEE 802.11-2007 was then made obsolete by the IEEE 802.11-2012, which was finalized by task group TGmb as REVmb or IEEE 802.11mb. This revision brought together the k, r, y, n, w, p, z, v, u, and s standards. Beyond these standards, there are many that are assigned to maintenance, specific applications, industrial/commercial, government, security, and data-communication protocols. (See “Uncommon Letters In Your Soup Bowl.”)

Currently Used And Updated Standards

Of course, then there are the commonly used and frequently updated standards, such as IEEE 802.11a, b, g, and n. IEEE 802.11a has undergone many transformations, extensions, and additions since 1999—including gaining the functionality added by standards h and y. The IEEE 802.11a standard, which uses orthogonal frequency division multiplexing (OFDM), has 20-MHz bandwidths in the 5.0- and 3.7-GHz bands. It allows for data rates from 1.5 to 54.0 Mb/s at ranges of 35 m (indoors) to 120 m (outdoors) with a single data stream. The 3.70-GHz enhancement increased the power limits of 802.11a in that band, increasing the outdoor wireless range to 5000 m in the US.

IEEE 802.11b—the most commonly used WLAN standard in the 2.4-GHz band—has been available to market products since 2000. IEEE 802.11b has 20-MHz bandwidth with a single data stream. It operates from 1 to 11 Mb/s and has an indoor range of 35 m and an outdoor range of 140 m. IEEE 802.11b uses the Direct Sequence Spread Spectrum (DSSS) modulation technique. It commonly suffers from interference from other commonly used wireless devices, such as microwaves, baby monitors, Bluetooth devices, cordless telephones, and amateur-radio equipment.

IEEE 802.11g, which is an updated version of 802.11b, arrived in 2003. It operates in the same 2.4-GHz frequency band. By using the same OFDM modulation technique as 802.11a, however, it increases data rates to 54 Mb/s. IEEE 802.11g devices offer only a single data stream. They have an indoor range of 38 m and an outdoor range of 140 m. The devices suffer from the same interference problems as those using IEEE 802.11b. They also face an additional problem, as 802.11b devices cause a decrease in data rates for 802.11g devices.

Added in 2009, IEEE 802.11n is an amendment to the standards that as multiple-input multiple-output (MIMO) antennas. It increases data rates over multiple channels using both a 20-MHz band within the 2.4-GHz band and a 40-MHz band within the 5.0-GHz band. The 2.4-GHz operations of 802.11n data rates range from 7.2 to 72.2 Mb/s while the 5.0-GHz data rates, individually, are 15 to 150 Mb/s. The range of 802.11n devices can use up to four data streams with ranges of 70 m indoors and 250 m outdoors using OFDM modulation. 

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