Convex Space Building Discretization for Ray-Tracing

Abstract

This paper describes a point to multipoint three-dimensional convex space-based ray-tracing technique. This visibility list is calculated and stored and can be reused as needed. What distinguishes our method is that the visibility list is transmitter location independent, is a three dimensional implementation and is highly computationally efficient. The division of the building into free and filled convex spaces leads to an efficient Method of Images reflection and diffraction path generation algorithm. This technique can be used to optimise the locations of base transceivers in a highly efficient manner. The first step in producing this tool is the generation of efficient ray-tracing algorithms. The ray-tracing algorithm was specifically designed for later incorporation into a transmitter optimisation algorithm. This requires a fast ray-tracing method because of its computationally intensive needs -running multiple times over a point-to-multipoint grid. Our algorithm is executed for sample building environments and then for a real building and compared with measurements to confirm its validity. It is clear that the results are in good agreement but do indicate that a highly accurate spatial modeling of the building is required.

An Efficient Ray-Tracing Based Model Dedicated to Wireless Sensor Network Simulators for Smart Cities Environments

“…The calculation times for these methods are often not given. When they are available, they show either that these methods can only deal with very simple environments (an interior scene with 4 rooms [46] or an exterior scene made up of 64 buildings [47]), or that they are based on a non-exact and costly visibility pre-process [43], which would miss some significant contributions. In the context of WSN smart city simulators, the potentially high number of sensors and their dynamic behavior imply the need for continuous updating of the calculated channel estimate in very complex environments.…”

Validation of a volume integral equation method for indoor propagation modelling

“…6 and 7 it is compared against 3D ray tracing and the measurements. The 3D ray tracing model was developed by Kenny and Nuallain [40]. It considers up to third-order reflections and transmissions but does not consider diffraction or diffuse scattering.…”

Wireless Indoor Resource Optimization Meeting Prescribed User Capacity Requirements

“…The asymptotic solutions most widely used are ray optic techniques calculating direct line of site (LOS), reflections and diffractions from a server to a UE. The ray-tracing method we consider uses the method of images to calculate reflected and transmitted rays (see Kenny [5]). Two papers in the literature use very similar electromagnetic wave equations to the ones mentioned in this paper.…”

“…The environment will be a multi-story indoor building defined exactly as in Kenny [5]. The walls, doors, windows, floors and ceilings will consist of filled convex spaces having permittivity, permeability and conductivity parameters associated with them.…”

“…The tetrahedron method [16] of Yun will improve the situation by using a fast spatial technique that divides the building into tetrahedrons, thus removing the requirement for visibility algorithms. However, Kenny [5] attempts to go further by splitting the building structure of rooms, doors, corridors and such like into convex spaces/boxes describing the air in rooms as free (or empty) convex spaces and building materials in terms of distinct interconnected convex spaces/boxes. This results in a fast Method of Moments algorithm for calculating the reflection and diffraction paths in the ray-trace.…”