Wimax standards and Security The Wimax

Standardization and Certification

A group of industry leaders (Intel, AT&T, Samsung, Motorola, Cisco, and others) have been chartered to promote the adoption of WiMAX. Together they make up the WiMAX Forum, which has developed a certification pro- gram for WiMAX-enabled devices [1]. The goal of the forum is to define and conduct interoperability testing and award “WiMAX Certified^TM’’ labels to vendor systems that pass these tests. The approach is similar to the one taken

by the WiFi Alliance, which helped bring wireless LANs to the masses. The WiMAX certification process will also consider the European Telecommuni- cations Standards Institute’s MAN standard (HiperMAN), which will allow WiMAX-certified devices to work in both the United States and Europe. The HiperMAN and 802.16 are both being modified in a way such that they share the same PHY and MAC layers [1].

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   Frequencies
   

The initial 802.16 standard specifies operation frequencies between 10 and 66 GHz. The advantage of using these high frequencies is that they have more available bandwidth and less risk of interference. The disadvantage is that they require line-of-sight (LOS) environments. The 802.16a standard was adopted to provide operation in the 2 to 11 GHz frequency band. The use of these lower frequencies provides the ability to support nonline-of-sight (NLOS) operation [1].
Initial WiMAX deployments are expected to use the 5 GHz (license-exempt) and 2.5 GHz (licensed) frequency bands. Bands between 5.25 and 5.28 GHz will be the focus for rural areas with a low population density. For fixed wireless access, most countries have allocated the bands between 3.4 and
3.6 GHz but the United States, Mexico, Brazil, and some Southeast Asian nations, have chosen instead the bands between 2.5 and 2.7 GHz. There are also bands of interest smaller than 800 MHz, which are currently vacant or used for analog TV, due to their ability to penetrate obstacles and propagate further.
WiMAX will support flexible channel sizes, which will provide the ability to meet the many different channel size requirements and frequency bands from around the world. It also defines a dynamic frequency selection scheme, which helps minimize interference and increase performance.

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