08-10-2010, 10:55 AM
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Hiperlan 2
INTRODUCTION
Recently, demand for high-speed Internet access is rapidly increasing and a lot of people enjoy broadband wired Internet access services using ADSL ( Asymmetric Digital Subscriber Line) or cable modems at home. On the other hand , the cellular phone is getting very popular and users enjoy its location-free and wire -free services. The cellular phone also enables people to connect their laptop computers to the Internet in location-free and wire-free manners. However , present cellular systems like GSM (Global System for Mobile communications) can provide much lower data rates compared with those provided by the wired access systems, over a few Mbps(Mega bit per second).Even in the next generation cellular system, UMTS ( Universal Mobile Telecommunications System), the maximum data rate of its initial service is limited up to 384 kbps; therefore even UMTS cannot satisfy users’ expectation of high-speed wireless Internet access. Hence, recently, Mobile Broadband System (MBS) is getting popular and important and wireless LAN (Local Area Network) such as ETSI (European Telecommunication Standardization Institute) standard HIPERLAN (High PErformance Radio Local Area Network) type2 (denoted as H/2) is regarded