Radio waves scatter off buildings and bend around corners depending on their carrier frequency. The University of Bristol is a world leader in the modelling of radiowave propagation. Today all cellular and Wi-Fi services operate at frequencies below 6GHz. One of the innovations in 5G is the introduction of new ‘millimeter wave’ bands at 26GHz and 60GHz. These introduce significant new challenges in terms of electromagnetic modelling. At such high frequencies the surfaces of buildings become ‘electrically rough’ and this scatters the radio signals in all directions. Using ultra-high resolution 3D city models (obtained by laser scanning from drone and/or aircraft platforms), it is possible to predict how these radiowaves travel from 5G basestations to your mobile device. The tools in development in the labs at Bristol will be used to support the 5G network planning process, ensuring appropriate services are delivered as required throughout the city.