Wi-Fi Standards, 802.11A/B/G/N/AC Explained
Wi-Fi is a wireless networking technology that uses radio waves to provide wireless high-speed Internet access. A common misconception is that the term Wi-Fi is short for “wireless fidelity,” however Wi-Fi is a trademarked phrase that refers to IEEE 802.11x standards.
Wi-Fi originated in Hawaii in 1971, where a wireless UHF packet network called ALOHAnet was used to connect the islands. Later protocols developed in 1991 by NCR and AT&T called WaveLAN became the precursor to the IEEE 802.11 standards.
The Wi-Fi Alliance was formed in 1999 and currently owns the Wi-Fi registered trademark. It specifically defines Wi-Fi as any “wireless local area network (WLAN) products that are based on the Institute of Electrical and Electronics Engineers’ (IEEE) 802.11 standards.”
What Does a/b/g/n Means In Wi-Fi?
The first “letter” following the June 1997 approval of the 802.11 standard, this one provided for operation in the 5GHz frequency, with data rates up to 54Mbps. Counterintuitively, 802.11a came out later than 802.11b, causing some confusion in the marketplace because people expected that the standard with the “b” at the end would be backward compatible with the one with the “a” at the end.
Released in September 1999, it’s most likely that your first home router was 802.11b, which operates in the 2.4GHz frequency and provides a data rate up to 11 Mbps. Interestingly, 802.11a products hit the market before 802.11a, which was approved at the same time but didn’t hit the market until later.
Approved in June 2003, 802.11g was the successor to 802.11b, able to achieve up to 54Mbps rates in the 2.4GHz band, matching 802.11a speed but within the lower frequency range.
802.11n (Wi-Fi 4)
The first standard to specify MIMO, 802.11n was approved in October 2009 and allows for usage in two frequencies – 2.4GHz and 5GHz, with speeds up to 600Mbps. When you hear wireless LAN vendors use the term “dual-band”, it refers to being able to deliver data across these two frequencies.
Also known as Wi-Fi HaLow, 802.11ah defines operation of license-exempt networks in frequency bands below 1GHz (typically the 900 MHz band), excluding the TV White Space bands. In the U.S., this includes 908-928MHz, with varying frequencies in other countries.
The purpose of 802.11ah is to create extended-range Wi-Fi networks that go beyond typical networks in the 2.4GHz and 5GHz space (remember, lower frequency means longer range), with data speeds up to 347Mbps.
Approved in December 2012, 802.11ad is very fast – it can provide up to 6.7Gbps of data rate across the 60 GHz frequency, but that comes at a cost of distance – you achieve this only if your client device is situated within 3.3 meters (only 11 feet) of the access point.
802.11ac (Wi-Fi 5)
Current home wireless routers are likely 802.1ac-compliant, and operate in the 5 GHz frequency space. With Multiple Input, Multiple Output (MIMO) – multiple antennas on sending and receiving devices to reduce error and boost speed – this standard supports data rates up to 3.46Gbps.
Some router vendors include technologies that support the 2.4GHz frequency via 802.11n, providing support for older client devices that may have 802.11b/g/n radios, but also providing additional bandwidth for improved data rates.