Worldwide Interoperability for Microwave Access (WiMAX)

WiMAX is a standards-based technology enabling the delivery of last mile wireless broadband access as an alternative to wired broadband like cable and DSL. WiMAX provides fixed , nomadic, portable and, soon, mobile wireless broadband connectivity without the need for direct line-of-sight with a base station. In a typical cell radius deployment of three to ten kilometers, WiMAX Forum Certified™ systems can be expected to deliver capacity of up to 40 Mbps per channel, for fixed and portable access applications. This is enough bandwidth to simultaneously support hundreds of businesses with T-1 speed connectivity and thousands of residences with DSL speed connectivity. Mobile network deployments are expected to provide up to 15 Mbps of capacity within a typical cell radius deployment of up to three kilometers. It is expected that WiMAX technology will be incorporated in notebook computers and PDAs by 2007, allowing for urban areas and cities to become “metro zones” for portable outdoor broadband wireless access.

Fixed WiMAX (The IEEE 802.16d standard)

802.16-2004 WiMAX. This is based on the 802.16-2004 version of the IEEE 802.16 standard and on ETSI HiperMAN. It uses Orthogonal Frequency Division Multiplexing (OFDM) and supports fixed and nomadic access in Line of Sight (LOS) and Non Line of Sight (NLOS) environments. Vendors are developing indoor and outdoor Customer Premises Equipment (CPE) and laptop PCMCIA cards. The initial WiMAX Forum profiles are in the 3.5 GHz and 5.8 GHz frequency bands. The first certified products were issued by the beginning of 2006.

The NLOS technology and the enhanced features in WiMAX make it possible to use indoor customer premise equipment (CPE). This has two main challenges; firstly overcoming the building penetration losses and secondly, covering reasonable distances with the lower transmit powers and antenna gains that are usually associated with indoor CPEs. WiMAX makes this possible, and the NLOS coverage can be further improved by leveraging some of WiMAX’s optional capabilities. This is elaborated more in the following sections.

Mobile WiMAX (The IEEE 502.16e standard)

The ongoing evolution of IEEE 802.16 will expand the standard to address mobile applications thus enabling broadband access directly to WiMAX-enabled portable devices ranging from smart phones and PDAs to notebook and laptop computers. The beauty if WiMAX originates from being a Broadband Wireless Access (BWA) sharing all the benefits of these systems like high quality and high speed and also a standard technology with all the benefits of standardization like large volume of vendor products through standardized parts which leads to greater production efficiency, also interoperability between vendor equipment and between different generations of the system provides lower system costs and both faster and cheaper access to more widely available, higher quality of service.

802.16e WiMAX Optimized for dynamic mobile radio channels, this version is based on the 802.16e amendment and provides support for handoffs and roaming. It uses Scalable Orthogonal Frequency Division Multiplexing Access (SOFDMA), a multi-carrier modulation technique that uses sub channelization. Service providers that deploy 802.16e can also use the network to provide fixed service. The WiMAX Forum has not yet announced the frequency bands for the 802.16e profiles, but 2.3 GHz and 2.5 GHz are the most likely initial candidates. Certification is expected to start in the first quarter of 2007.