Rain Spatial Classification for Availability Studies of Point-to-Multipoint Systems

Signal propagation at frequencies above 10 GHz suffers from significant attenuation due to precipitation. This has to be taken into account when planning point-to-multipoint (PMP) wireless systems operating in the millimeter wave band. Given the nonuniform spatial distribution of the rain rate, the site diversity concept emerges as one of the mitigation techniques. For propagation studies of PMP systems during rain events, rain spatial properties and their corresponding impact on system behavior has to be investigated. An extensive database of rainfall radar data for various types of rain events has been established. System outage improvement was studied using space-time simulations of PMP systems under specific rain conditions. A new approach to rain spatial classification according to its impact on system performance is proposed, using a single rainfall spatial parameter. Examples of its calculation are presented