November 1, 2016
Every year our mobile and computing devices are more intelligent with faster processing, greater storage and a growing amount of application options. Consumer and business users alike require and expect WiFi availability and bandwidth in homes, offices and public venues. In addition, the growth of streaming video, predicted to be 80% of all Internet traffic by 2019, is only intensifying the demand on WiFi technology and infrastructure.
Since the inception of 802.11 in 1997 the IEEE established standards for wireless local area communication (WLAN) between computers. These standards and their continuing revisions are incorporated into manufacturer's products and denote the capabilities of these products. A brief summary of the standards are outlined below.
802.11a - supports data rates up to 54 Mbps in the 5 GHz frequency band, which has significantly less congestion than other bands and less interference from other devices ensuring better signal integrity and fewer dropped connections. One disadvantage is that its effective overall range is slightly less than that of 802.11b and 802.11g. 802.11a signals are more readily absorbed by walls and other solid objects compared to 802.11b/g.
802.11b - was more affordable than 802.11a equipment and better at penetrating solid objects (i.e. walls) compared to 802.11a, however, maximum throughput of 11 Mbps is much lower than 802.11a's 54 Mbps. Also, the 802.11b devices operate in the 2.4 GHz frequency band which is not as effective as 802.11a at penetrating trees and leaves. The 2.4 GHz signals are absorbed by water thus limited in outdoor range.
802.11g - also operates in the 2.4 GHz frequency band, supports a maximum throughput of 54 Mbps and is backward compatible with 802.11b devices/networks. The 2.4 GHz band is a crowded with the potential of much interference. Microwave ovens, baby monitors, Bluetooth devices and cordless telephones are some examples of devices utilizing the 2.4GHz band.
802.11n - was developed to improve network throughput by utilizing multiple antennas to increase data rates. The 802.11n standard uses both 2.4 GHz and 5 GHz bands and Multiple-input Multiple-output (MIMO) technology which is a technique for sending and receiving more than one wireless signal on the same radio channel at the same time increasing overall throughput (up to 600 Mbps)!
802.11ac (Wave 1) - supports data rates up to 1.3 Gbps, operates in the 5 GHz band, and can handle up to four spatial streams (Wave 1) transmitting and three receiving along with wide 80 MHz (Wave 1) channels. 802.11ac features multi-user MIMO (MU-MIMO) where an access point can send data to up to four client radios simultaneously as compared to 802.11n access points that can only communicate to one client at a time. Implementing MU-MIMO improves Wi-Fi network efficiencies even as more clients are added to the network.
802.11ac (Wave 2) - supports data rates up to 2.3 Gbps, operates in the 5 GHz band, and can handle up to four special streams transmitting and receiving (Wave 2) and wide 160 MHz (Wave 2) channels. MU-MIMO is also implemented in Wave 2 as well as the added feature of additional 5 GHz channels allowing greater flexibility for RF to move channels when there is a high degree of interference.
802.11ax - will be able to subdivide signals even further, using a technology called MIMO-OFDM. (Orthogonal frequency division multiplexing). 802.11ax is aimed at improving high density, high capacity, environments supporting data rates up to 10 Gbps. 802.11ax will operate in the 2.4 GHz and 5 GHz bands. Ratification is expected in 2019.
For more information about the technologies incorporated into 802.11 standards and the products that utilize them contact Direct Network Services at 978-952-6000.
