In this article we will talk about 802.11 Standards, and in previous article we already discussed about Cisco Security Appliance.
The world of wireless communications is vast. However, for particular job-related skills, we want to focus on specific aspects of Wi Fi. The best place to start is with the IEEE 802.11 WLAN standards. These standards define how radio frequencies are used for wireless links. Most of the standards specify that wireless devices have one antenna to transmit and receive wireless signals on the specified radio frequency (2.4 GHz or 5 GHz). Some of the newer standards that transmit and receive at higher speeds require access points (APs) and wireless clients to have multiple antennas using the multiple-input and multiple-output (MIMO) technology. MIMO uses multiple antennas as both the transmitter and receiver to improve communication performance. Up to eight transmit and receive antennas can be used to increase throughput.
Various implementations of the IEEE 802.11 standard have been developed over the years. The table highlights these standards.
|IEEE WLAN Standard||Radio Frequency||Description|
|802.11||2.4 GHz||speeds of up to 2 Mbps|
|802.11a||5 GHz||speeds of up to 54 Mbpssmall coverage arealess effective at penetrating building structuresnot interoperable with the 802.11b and 802.11g|
|802.11b||2.4 GHz||speeds of up to 11 Mbpslonger range than 802.11abetter able to penetrate building structures|
|802.11g||2.4 GHz||speeds of up to 54 Mbpsbackward compatible with 802.11b with reduced bandwidth capacity|
|802.11n||2.4 GHz 5 GHz||data rates range from 150 Mbps to 600 Mbps with a distance range of up to 70 m (230 feet)APs and wireless clients require multiple antennas using MIMO technologybackward compatible with 802.11a/b/g devices with limiting data rates|
|802.11ac||5 GHz||provides data rates ranging from 450 Mbps to 1.3 Gbps (1300 Mbps) using MIMO technologyUp to eight antennas can be supportedbackwards compatible with 802.11a/n devices with limiting data rates|
|802.11ax||2.4 GHz 5 GHz||latest standard released in 2019also known as Wi-Fi 6 or High-Efficiency Wireless (HEW)provides improved power efficiency, higher data rates, increased capacity, and handles many connected devicescurrently operates using 2.4 GHz and 5 GHz but will use 1 GHz and 7 GHz when those frequencies become availableSearch the internet for Wi-Fi Generation 6 for more information|