Splash

SPLAT! is a wonderful tool for RF analysis over terrain. Unfortunately, it only works with a few terrain sources and only uses one core for processing.

Splash is three things, in this order:

1. A learning project to teach myself about the maths and physics underlying the Longley-Rice Irregular Terrain Model (ITM) as I go about porting it to Rust.
2. A learning project to teach myself deep optimisation over modern hardware, using at least SIMD and hopefully GPU to dramatically improve modelisation performance.
3. A production-grade interface to the ITM, and eventually other models.

Porting goals

• Not merely a port of the C++ port of the FORTRAN original, but a full refactor, with all functions and variables named sensibly.
• Everything thoroughly documented inline, with the minor goal that one should be able to understand (at a high level) how the ITM works “simply” by reading Splash’s source.
• 1950-era approximations replaced by exact versions for math functions where possible.
• Entirely safe code.
• Separation of preparation and execution routines.

Research and papers

Longley-Rice ITM

• The Irregular Terrain Model: FORTRAN implementation with descriptions (NTIA 2002)
• Hufford 1995: The (ITM) Algorithm, v1.2.2
• Hufford-Longley-Kissick 1982: A Guide to the Use of the ITM
• McKenna 2016: Propagation Measurement Workshop (Slides)

Background

• Norton 1959: Transmission Loss in Radio Propagation II
• Handbook on Ground Wave Propagation: Edition of 2014 (ITU Radiocommunication Bureau)
• Phillips 2012: Geostatistical Techniques for Practical Wireless Network Coverage Mapping

Parallel ITM

• Song 2011: Parallel Implementation of the Irregular Terrain Model (ITM) for Radio Transmission Loss Prediction Using GPU and Cell BE Processors
• Musselman 2013: An OpenCL Implementation of the Irregular Terrain with Obstructions Model (ITWOM)

Accuracy studies

• Sun 2015: Propagation Path Loss Models for 5G Urban Micro-and Macro-Cellular Scenarios
• Sun 2016: Investigation of Prediction Accuracy, Sensitivity, and Parameter Stability of Large-Scale Propagation Path Loss Models for 5G Wireless Communications
• Abhayawardhana 2005: Comparison of Empirical Propagation Path Loss Models for Fixed Wireless Access Systems

Other models or improvements

• El-Sallabi 2011: Terrain Partial Obstruction LOS Path Loss Model for Rural Environments
• Phillips 2012: Geostatistical Techniques for Practical Wireless Network Coverage Mapping
• MacCartney 2017: Rural Macrocell Path Loss Models for Millimeter Wave Wireless Communications