Performance analysis of modified terrain propagation models against their reference models in terms of speed and accuracy

Wave propagation modelling is a key component in the design of cellular mobile communications networks. Two of the critical parameters in a propagation tool are its computational speed and accuracy. Ideally, the radio planning engineer seeks for an appropriate combination of both parameters. However, very often, a compromise has to be made between these two aspects, which is often guided by the specific system needs and the link margin available. In order to address these needs, this paper investigates two models that are modifications of some existing models to improve their speed vs. accuracy performance. As reference terrain propagation models, the narrow angle parabolic equation (NAPE) and the slope-UTD model (STD-UTD) are used. In principle a full-wave model is more accurate than a canonical model since the terrain profile is better taken into account. However by the same token, a canonical model is faster. We describe the modified models, namely the NAPE-FS (free-space) and the selected edges UTD (SE-UTD) model. An evaluation of their performance against their reference models is carried out by comparing predictions with measurements for profiles from a terrain database in Aalborg, Denmark. Conclusions drawn from the set of results are outlined.