Window effect on wall penetration loss in mobile communications
In mobile communication scenarios, a window opening on a wall enhances the field strength inside the room, as compared to a whole wall. Scarce models in the literature address this topic, or objectively quantify this effect relating it to window dimensions - this is the objective of the present paper. Wall and window are treated as an antenna aperture with the appropriate field distribution, which re-radiates its near field into the room. Measurements on a scaled model of a wall with different window sizes show good agreement with simulations. Based on simulation results, a statistical model is constructed to enable fast quantification of the window effect through a "window gain" parameter.
A ray-tracing approach for indoor/outdoor propagation through window structures
A ray-tracing approach for indoor/outdoor propagation through windows is proposed. Using both the finite-difference time-domain (FDTD) method and a ray-tracing algorithm, several cases of indoor/outdoor propagation through windows were investigated. It is shown that wave transmission through windows cannot generally be accounted for through a single transmission coefficient parameter. Instead, a full diffraction pattern needs to be accounted for and multiple-ray representation is therefore required. It is also shown that a single window model may be used to calculate transmission through set of windows in a typical building structure as a building block. Results from the implementation of a multiple-ray representation and FDTD simulations showed good agreement. Results were validated for both normal and oblique incident cases. The developed ray-tracing approach, therefore, facilitates the use of the developed window model in available ray-tracing algorithms often used for propagation characterization of urban environments. Simulation results were further validated by conducting measurements on scaled models at 30 GHz. The experimental results agreed well with the simulation data, thus validating the accuracy of the developed ray-tracing model for transmission through windows.
Substation automation based on IEC 61850 with new process-close technologies
New technologies in primary equipment like nonconventional instrument transformers require new interfaces to the substation automation system. The future standard IEC 61850 perfectly supports this requirement. With the introduction of the new technologies and the use of IEC 61850, a more decentralized architecture of the substation automation system will be possible. This provides several benefits but a careful system design is required to maintain the overall reliability of the system.