The International Workshop on Rainfall Measurement Based on Microwave (MW) links from Commercial Cellular Communication Networks (Rain Cell) was held in Ouagadougou, Burkina Faso, from 30 March to 2 April 2015. The workshop's main objective was to build awareness and provide training on a technique that can provide accurate rainfall mapping in areas with poor rain gauge or weather radar coverage. The workshop brought together 87 participants representing research centers and weather services from 18 countries. A subgroup of 30 workshop participants followed a 2-day technical training course that covered in detail the physics of microwave attenuation by rain, other sources of signal fluctuations such as wet antennas, signal processing techniques to detect wet and dry periods and quantify rain-induced attenuation, and quantitative rain-rate estimation from microwave attenuation.