Table 5 IEEE 802.11 family of standards 10 Specification Description Main Purpose Pros Cons IEEE 802.11 (June, 1997) The earliest standard, allowing 1- 2 Mbps of bandwidth in the 2.4 GHz band uses FHSS, DSS, and IR in the physical layer, covering typical range of m. Basic wireless technology standard IEEE ab (Sep, 1999) Second revision to the original 802.11 standard bandwidth of 54 Mbps in 5 GHz RF band uses OFDM; typical range ism. Higher Performance Fast maximum speed no signal interference as it operates in licensed frequency. Highest cost short signal range that is more easily obstructed. IEEE b (Sep., 1999) First revision to the original 802.11 standard bandwidth of 11 Mbps in 2.4 GHz RF band uses DSSS/CCK; typical range ism. Performance Enhancements Lowest cost good signal range that is not easily obstructed slowest maximum speed interference with home appliances on the unlicensed frequency band IEEE db (b Defines physical layer requirements to satisfy regulatory domains not covered by the existing standards enable client adjusts its frequencies, power levels and bandwidth accordingly. Promote Worldwide Use IEEE ebb (b) Defines a set of Quality of Service enhancements for wireless LAN applications through modifications of the Media Access Control (MAC) layer to support applications such as such as VoIP and video. QOS Enhancements IEEE F (2003) A standard designed to enforce interoperability of multi-vendor APs within a WLAN network infrastructure. It uses the Inter- Access Point Roaming Protocol, which lets a roaming user transparently switch from one access point to another while moving around. Interoperability IEEE g (June, 2003) Fourth revision to the original 802.11 standard bandwidth of 54 Mbps in 2.4 GHz RF band uses OFDM/PBCC; typical range is Higher Performance with b Backward Fast maximum speed good signal range Costs more than b chances of interference on
Wireless Local Area Network (WLAN): Security Risk Assessment and Countermeasures Nwabude Arinze Sunday - 20 -