Overview of IEEE 802.11 Wireless Local Area Network Standards
Standards for IEEE 802.11 have been designed to provide wireless access in the sub 1 GHz frequency band. IEEE 802.11 (also called IEEE 802.11a, IEEE 802.11b, IEEE 802.11g, or IEEE 802.11n) is an IEEE standard for wireless networking. IEEE 802.11 defines physical and media access control (MAC) layers and a data link control (DLC) layer for wireless networks.
Standards for IEEE 802.11a are based on Orthogonal Frequency-Division Multiplexing (OFDM), which spreads data over a large number of carriers that are spaced apart at precise frequencies. IEEE 802.11b extended the range of IEEE 802.11 to include high-rate data transmission with the use of direct sequence spread spectrum (DSSS) modulation. IEEE 802.11g is used for wireless home networking in the 2.4 GHz ISM frequency band. The IEEE 802.11g standard is backward compatible with IEEE 802.11b. Wireless devices operating in the 2.4 GHz ISM band use the same spectrum and thus can coexist with each other. In addition, IEEE 802.11g wireless networking technology is backward compatible with older IEEE 802.11b wireless networking technology. IEEE 802.11n uses a technique called OFDM, which makes it a more reliable technology than previous wireless standards.
The basic working principle of IEEE 802.11 technology is using OFDM to split a data stream into multiple narrowband sub-carriers. Each of these sub-carriers operates as a separate independent data stream. Thus, with IEEE 802.11b and 802.11g standards it is possible to use either 20, 40, 80, or 160 sub-carriers, which is a different number of sub-carriers for each data stream.
IEEE 802.11 technology, especially 802.11n and 802.11ac, can allow data to be transferred at very high data rates. Currently, 802.11n is operating at data rates of up to 600 Mbit/s (54 Mbit/s) in the 5 GHz band, whereas the 802.11ac standard can support data rates of up to 1 Gbit/s (90 Mbit/s) using the 60 GHz frequency band. The higher bandwidth and the added MIMO (multiple input multiple output) technology in IEEE 802.11n and 802.11ac allows for higher reliability and better wireless coverage. These high data rates and high reliability factors of IEEE 802.11 technology can be used to provide wireless network services such as home networking and hotspots.
An overview of the IEEE 802.11a, IEEE 802.11b, IEEE 802.11g, IEEE 802.11n and IEEE 802.11ac standards and their respective 0b46394aab