An Analysis of Electric Field Strength for Planning Indoor Wireless Networks at Various Frequencies

Understanding the characteristics of radio wave propagation is a very important task for ensuring the required signal coverage for indoor wireless communication systems. The received signal strengths are highly affected when blocked by obstacles such as human occupants, doors, walls, windows, etc. This thesis investigated the E-field distributions inside a Victorian terraced house. Many scenarios are presented to investigate some important elements that have a significant effect on E-field distributions, such as opening and closing doors, the movement and number of human occupants and the location of the transmitter. These are considered for indoor signal propagation at various frequencies, specifically 5.8 GHz, 2.4 GHz, 868 MHz and 433 MHz. The distribution of the E- field strength within the building has been obtained using the FEKO simulation suite. The methods used in the simulation are geometrical optics and the uniform theory of diffraction. The results demonstrate that when the transmitter is located near to a wall, then the field distributions within the Victorian house are attenuated due to more reflections and multipath effects. Also, the results show that the door’s status and human occupancy effect on the electric field coverage at 5.8 GHz and 2.4 GHz is more significant than at 868 MHz and 433 MHz. The practical results demonstrate that the radio signals can penetrate through several adjacent walls within the same floor, however they became very weak when they go through different floors. This indicates that the deployment and positioning of smart meters in domestic properties has to be carefully considered. Our results clearly prove that extensive E-field measurements should be performed prior to the deployment of wireless communication system within the building.