802.11 and 802.11x refers to a family of specifications developed by the IEEE for wireless LAN (WLAN) technology . 802.11 specifies an over-the-air interface between a wireless client and a base station or between two wireless clients. The IEEE accepted the specification in 1997.
There are several specifications in the 802.11 family:
802.11
The first wireless LAN specification developed by the IEEE in 1997. The 802.11 specification defines three types of wireless LAN, all operating at a data transmission rate of 1Mbps or 2Mbps. 802.11 FHSS and 802.11 DSSS use radio frequency radiation as the transmission medium. The third 802.11 specification is based on diffuse infra-red transmission.
802.11a
Operates in the UNII (Unlicensed National Information Infrastructure) 5GHz band and supports transmission rates up to 54Mbps. 802.11a uses Orthogonal Frequency Division Multiplexing (OFDM), as opposed to the DSSS or FHSS schemes used in 802.11b and 802.11 networks. Due to its higher frequency of operation, the range of 802.11a equipment is less that of lower frequency systems such as 802.11b and 802.11g. This can increase the cost of an 802.11a network, because a greater number of access points may be required. Since it operates in a different RF band, 802.11a cannot work directly with 802.11b or 802.11g equipment. Using multi-mode 802.11a/b/g access points and/or client adapters will resolve this problem.
802.11b
Currently the most popular and widespread standard for wireless LANs, which operates in the 2.4GHz ISM band and supports data rates up to 11Mbps. Also known as 802.11 High-Rate (HR) and as Wi-Fi, 802.11b uses the DSSS spread spectrum transmission scheme, and operates at data rates of 1Mbps, 2Mbps, 5.5Mbps and 11Mbps.
802.11g
The latest in the 802.11 wireless LAN series, 802.11g operates in the 2.4GHz ISM band and uses Orthogonal Frequency Division Multiplexing (OFDM) to support data rates up to 54Mbps. 802.11g equipment, also known as 54g™, 802.11g can also fall back to 802.11b operation. Therefore an 802.11b device can work directly with an 802.11g device using 802.11b mode.
802.11i
The new IEEE standard for security in 802.11 WLANs. 802.11i supersedes the WEP scheme originally introduced with 802.11b wireless LANs. Devices that fully support 802.11i can use WEP, Wi-Fi Protected Access (WPA) or AES for data encryption.
802.1x
802.1x is a scheme for port-based security, which requires a user or device to authenticate with the wireless access point or a wired LAN switch/hub, before it can communicate with other devices in the network. 802.1x is used in conjunction with the Extensible Authentication Protocol (EAP).
802.3
Most wired networks conform to the 802.3 specification for CSMA/CD based Ethernet networks.
802.x
Refers to the IEEE 802.xx series of specifications for wired and wireless LANs.
There are several specifications in the 802.11 family:
802.11
The first wireless LAN specification developed by the IEEE in 1997. The 802.11 specification defines three types of wireless LAN, all operating at a data transmission rate of 1Mbps or 2Mbps. 802.11 FHSS and 802.11 DSSS use radio frequency radiation as the transmission medium. The third 802.11 specification is based on diffuse infra-red transmission.
802.11a
Operates in the UNII (Unlicensed National Information Infrastructure) 5GHz band and supports transmission rates up to 54Mbps. 802.11a uses Orthogonal Frequency Division Multiplexing (OFDM), as opposed to the DSSS or FHSS schemes used in 802.11b and 802.11 networks. Due to its higher frequency of operation, the range of 802.11a equipment is less that of lower frequency systems such as 802.11b and 802.11g. This can increase the cost of an 802.11a network, because a greater number of access points may be required. Since it operates in a different RF band, 802.11a cannot work directly with 802.11b or 802.11g equipment. Using multi-mode 802.11a/b/g access points and/or client adapters will resolve this problem.
802.11b
Currently the most popular and widespread standard for wireless LANs, which operates in the 2.4GHz ISM band and supports data rates up to 11Mbps. Also known as 802.11 High-Rate (HR) and as Wi-Fi, 802.11b uses the DSSS spread spectrum transmission scheme, and operates at data rates of 1Mbps, 2Mbps, 5.5Mbps and 11Mbps.
802.11g
The latest in the 802.11 wireless LAN series, 802.11g operates in the 2.4GHz ISM band and uses Orthogonal Frequency Division Multiplexing (OFDM) to support data rates up to 54Mbps. 802.11g equipment, also known as 54g™, 802.11g can also fall back to 802.11b operation. Therefore an 802.11b device can work directly with an 802.11g device using 802.11b mode.
802.11i
The new IEEE standard for security in 802.11 WLANs. 802.11i supersedes the WEP scheme originally introduced with 802.11b wireless LANs. Devices that fully support 802.11i can use WEP, Wi-Fi Protected Access (WPA) or AES for data encryption.
802.1x
802.1x is a scheme for port-based security, which requires a user or device to authenticate with the wireless access point or a wired LAN switch/hub, before it can communicate with other devices in the network. 802.1x is used in conjunction with the Extensible Authentication Protocol (EAP).
802.3
Most wired networks conform to the 802.3 specification for CSMA/CD based Ethernet networks.
802.x
Refers to the IEEE 802.xx series of specifications for wired and wireless LANs.
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