Advanced Site Solutions for WiMax

Introduction The allure of the WiMax wireless high speed data service is well documented. Significant effort has been invested in developing a spectrally efficient modulation that is rather multipath impervious. Still, the laws of physics dictate that we need to get power from point A to point B that is above the receiver threshold. This requires rigorous RF planning and hardware design. Unlike mobile phone systems, we need to provide the receiver with a C/I ratio that allows for the use of a modulation with a high spectral efficiency. In this paper we compare the properties of a WiMax site to those of a cellular phone site. Like the cellular systems of the eighties, initial WiMax deployments will be noise limited. However, as the deployments increase the system will quickly be interference limited. This capacity limitation is the subject of this paper. Noting the difference between WiMax and cellular, the known limitations of a capacity limited cellular network is used to predict what will happen with WiMax deployments. Well tested site planning and transport configurations that maximize system capacity and reliability are then outlined. While analysis has indicated that MIMO techniques may be able to increase the spectral efficiency by a factor or two, the techniques presented here can easily triple the spectral efficiency without introducing cost.