One of the issues facing network designers planning a home or office wireless network is access point (AP) placement in a way to provide minimal signal loss. When there are only a few obstructions that may cause signal disruption, a centrally located AP may be the best bet. This is not the case with the complex floor plans or if we choose multi-story coverage. The process of finding the best location for the AP may be tedious in practice, especially if we want to test many alternative locations with no easy access or we just don't have all the cabling for the experimentation. Signal prediction software can provide a significant assistance.
Although the maximum transmitting power is limited by local regulations, the range of Wi-Fi networks is constantly improving by using innovative radio transmitting techniques, such as dual-band operation, multiple-input multiple-output antennas, new modulation standards and beam forming. However, the most important limit which cannot be overcome is set by nature. Electromagnetic waves propagate in space and interact with matter in a way that irreversibly reduces the amount of energy for reception.
Signal propagation prediction is used extensively in wireless system design. When accompanied with detailed knowledge of the environment geometry, ray-tracing technique can take into account the majority of paths the real signal would traverse and model actual physical phenomena responsible for propagation of electromagnetic waves. The method uses Fresnel equations for the determination of the reflection and transmission loss. Apart from geometry, the result depends heavily on the material characteristics such as permittivity, permeability and conductivity.
In general, ray-tracing gives better predictions than empirical methods at the cost of higher processing time. Signal3D, on the other hand, implements computationally efficient ray-tracing algorithm that reduces excessive running times by innovative programming approaches. User can further opt for faster computation by reducing the number of ray's interactions with the scene objects, in which case the signal computation is partially augmented with the empirical model. The material database with laboratory measured permittivity, permeability and conductivity at Wi-Fi frequencies is used.
Signal3D is a radio ray-tracing app intended to improve Wi-Fi signal coverage in indoor environments, such as apartments, homes or offices. The app offers a 3D user interface to define environment geometry and visualize signal prediction. In order to simplify indoor environment description only wall-like building block is needed. Each wall may have several openings or holes, which can be optionally filled with glass or opaque panel. Complex geometries can be defined using only this single type of primitive while providing user interface with fast learning curve. The radio propagation modelling is done by the Discrete Method of Images. The details are available in the paper published by Springer's 3D Research.
The app can be used to: locate a perfect spot for dispersing the signal, eliminate dead zones in a systematic way, isolate connectivity problems, evaluate network performance for access points in inconvenient locations, design a wireless network in challenging surroundings, provide Wi-Fi signal in wider area, and much more.