WiMAXWorldwide Interoperability for Microwave Access
Encouraged by the success of WLAN systems, WiMAX strives to deliver broadband data through high density urban and suburban wireless networks. It also facilitates long range backhauling to remote areas based on standardised and interoperable equipment. However, the key focus of WiMAX is on fixed nomadic and mobile applications such as
based on IEEE standards 802.16-2004 and 802.16-2005, respectively. Having two distinct WiMAX standards will allow operators to scale their networks to different needs, depending on whether they want to support last mile access only (Fixed WiMAX) or mobile roaming (Mobile WiMAX). Fixed WiMAX is a particularly interesting solution for providing last mile access in developing regions without any existing wireline infrastructure. It primarily targets residential and office users having no or no reliable access to broadband services today, and it will enable high speed access in remote areas for which up to now it has been too costly to provide broadband infrastructure. Mobile WiMAX will enable access to information while on the move, e.g. in the car, on the train or simply when walking around in metro areas. Once fixed broadband has become common feature, it can be expected that people would not like to miss it when roaming between different places.
WiMAX networks will be rolled out in a way similar to 2G and 3G sectorised networks. Contrary to 2G and 3G systems, many WiMAX deployments use an initial three sector arrangement to support sufficient capacity from the very start. As the networks grow, the antenna configuration may turn to a four sector arrangement and more and more base stations will be fitted into the system to cope with increased traffic. Very similarly to 2G and 3G networks, WiMAX will finally migrate to a microcell configuration with raw data rates of up to 100 Mbps being available within certain areas close to base stations.
Interoperability
Interoperability of equipment and networks is key to successful growth of WiMAX. Similarly to the Wi-Fi organisation, the WiMAX Forum has been formed as a non-profit organisation that promotes and certifies interoperability of products and networks and helps to establish WiMAX as an important wireless broadband access technology.
Frequency spectrum for WiMAX
Unlike WLAN networks, WiMAX networks will operate in licensed frequency bands which will provide accurate Quality of Service and help to protect operators’ investments.
The major frequency bands for WiMAX are
Additional frequency bands may be added in the near and midterm future. The licensing process has already started in many countries and has even been completed in others.
