Wireless technologies conform to a variety of standards and offer varying levels of security features. The principal advantages of standards are to encourage mass production and to allow products from multiple vendors to interoperate. WLANs are based on the IEEE 802.11 standard, which the IEEE first developed in 1997. The IEEE designed 802.11 to support medium-range, higher data rate applications, such as Ethernet networks, and to address mobile and portable stations.
The three physical implementations are:1.Direct sequence spread spectrum radio (DSSS) in the 2.4 GHz band,2.Frequency hopping spread spectrum radio (FHSS) in the 2.4 GHz band, and3.Infrared light (IR).
The types (modes) of The 802.11 standard:1- Ad Hoc Wireless LANsThe 802.11 standard is defined as "Independent Basic Service Sets" or IBSSs. A Basic Service Set (BSS) is a collection of stations that are either strictly within range of one another and communicating amongst themselves without an AP or a group of stations associated with one AP.
An IBSS is a BSS where stations communicate without an AP. Each BSS and IBSS is identified by a BSS identifier (BSSID) that is formatted the same as a WLAN NIC addresses (a 48 bit number). Each frame transmitted within an 802.11 WLAN includes the destination BSSID.
A common misconception is that Ad Hoc networks cannot be connected to wired networks. However, Ad Hoc networks can be connected to wired networks. The only restriction is that there can be only one IBSS and no roaming is possible. (3 Com. (2000))Bluetooth:Bluetooth has emerged as a very popular ad hoc network standard today. The Bluetooth standard is a computing and telecommunications industry specification that describes how mobile phones, computers, and PDAs should interconnect with each other, with home and business phones, and with computers using short-range wireless connections. Bluetooth network applications include...