2 Positioning the WLAN standards


2 Positioning the WLAN standards

Recent and rapid grow of wireless technologies as well as standards and interest group multiplicity make it difficult to position the various solutions. Therefore in this section we are trying to position the main initiatives.

802.11 standards are defined in IEEE. They target the specification of WLAN standards. Their initial use domain is the enterprise; however they are able to easily being used or adapted in other contexts (domestic, campus, public "hot spot").

Targeted terminals are PC (most are laptops) and PDA based. 802.11 specifies a core standard which is complemented by a number of extensions, each one being identified by an extension letter (802.11, 802.11a, 802.11b). Most current WLAN products conform to the 802.11b extension and support the "Wi-Fi" stamp, supposed to guarantee their interoperability.

HomeRF is a "voice/data" standard dedicated to domestic applications. It is based on a scheme derived from 802.11 for data support and a scheme derived from DECT for voice support. First products, only data oriented, have appeared on the market. However, it appears that most HomeRF promoters are turning to other technologies.

HiperLAN/2 is a European standard specified by ETSI in order to deploy very high bit rate WLANs. Initially, targeting the support of Wireless ATM networks, the standard has been opened to support other types of networks (Ethernet, IEEE 1394), which make it an adaptable standard for different environments eventually restrictive in terms of quality of service (enterprise, audio-visual etc).

Bluetooth had an initial scope of cabling replacement in the vicinity of mobile terminals, for example of the GSM type (PC connectivity, personal digital assistant, auricle, printer etc). This type of use should bring the technology to large developments, in particular for mobile Internet services support. It enables one to foresee the dynamic set-up of true "personal" networks connecting the various terminals of a given person. These initial aims made it short range (from one to several meters ) and a low consumption technology. Since the first announcements, industrial developments have evolved the technology by using higher emitting power. Those evolutions target directly the introduction of Bluetooth in WLAN products, used at a housing or enterprise scale with bit rates largely lower than those supported by 802.11 and HiperLAN/2 products.




Communicating With Smart Objects(c) Developing Technology for Usable[... ]stems 2003
Linux Troubleshooting for System Administrators and Power Users
ISBN: N/A
EAN: 2147483647
Year: 2005
Pages: 191

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