Last week, we looked at the ratification of the new Wi-Fi (wireless local area network) standard, 802.11n. This week, we look at the new standard and discuss how it performs better than the older Wi-Fi standard, 802.11g.
802.11g had a theoretical throughput rating of 54 Mbps but the actual speed fell to half of that or even lower. Still, the throughput was adequate for most uses when the standard was introduced in 2003 and, because it operated in the 2.4 GHz band, it was backward compatible with even older 802.11b devices.
The new 802.11n standard uses completely new technology in some areas and tweaks existing technologies in other areas to give Wi-Fi both more throughput and distance. The changes include multiple input-multiple output, channel bonding, and payload optimization.
Multiple input - multiple output (MIMO) is a new Wi-Fi technology that uses multiple antennas to transmit and receive multiple data signals. Instead of sending and receiving one data signal, MIMO can simultaneously transmit three signals while receiving two. The technology allows for a much higher throughput of data and it increases the distance between wireless devices. Where 802.11g Wi-Fi used only one of 14 available channels to send or receive data, 802.11n Wi-Fi introduces channel bonding which allows two separate channels to transmit data simultaneously increasing the total amount of data transmitted. Payload optimization is a tweaking of current technology that allows more data to be carried within each packet.
802.11n also provides backward compatibility for 802.11a, b and g devices so updating to new access points is possible without the need to upgrade the whole system. Together, the changes in the new Wi-Fi standard allow organizations the option to easily deploy low-cost, higher-speed wireless to satisfy the ever increasing appetite for more throughput.
Ron Poland is a professor in the Computer Information Systems AAS program at Clinton Community College. Poland is certified in company repair and networking by the Computer Technology Industry Association (CompTIA). He is also a Cisco certified network assistant. Questions may be sent to him via e-mail at firstname.lastname@example.org.