Analysis of wireless propagation within a Victorian house for smart meter applications

Abstract

Abstract — Smart meters utilizing wireless technology could help to improve building energy efficiency. Wireless smart meters have to be carefully deployed in the building to ensure reliable communication and optimize signal strength. This simulation study considers how changing the configuration within a Victorian terraced house affects the electric field strength. Ten scenarios are presented to investigate the effect of doors and human occupancy on RF signal propagation. Keywords—Smart meter, propagation, RF, wireless. I. I NTRODUCTION The European Community has committed to save energy among most of European Union (EU) nations [1]. Currently, power consumers in the UK are given the estimated reading of electricity, gas and water every three months. In most cases they are not fully aware of the total power consumption and may consume more than they expect. The UK government aims to let most customers get a real indication of their consumption by 2020. To achieve this a smart meter will be installed in every home, with the aim of raising consumer awareness of energy consumption and thereby reducing overall domestic energy consumption [2]. Smart wireless meters are used to record and display the energy consumption of a household for the purpose of optimal power management. They offer consumers the potential for lower energy bills by making them more aware of their energy usage and can benefit energy suppliers by providing higher resolution data on customer demand. Smart wireless meters therefore have to effectively communicate with each other. A variety of commercial standards are available for wireless sensor networks (WSN) communication, such as Bluetooth, 6lowpan, Wireless HART, Z-wave and ZigBee. The latter has proven to be an appropriate solution for the smart meters [3]. Improving the performance of wireless systems is becoming a very important element especially inside buildings. For a wireless friendly building, improving the signal coverage is one of the main issues studied in the literature [4]. There are many parameters that can affect the radio frequency (RF) signal's propagation inside the buildings. Among them are the structure of building, the type of materials and the incident angle of wave into the wall, windows or any other obstacles [5]. Researchers have investigated the effects of various building dielectric parameters and structures of internal wall on the performance of wideband channels [6, 7]. The results have shown that the path loss increases if one of the permittivity, loss tangent or thickness of the wall is increased. A door state (open or closed) and presence of people on indoor environment have a big impact on propagation of the signal. In [8] the author has studied the affect of the doors when they are open or closed on the propagation for the cases of line of sight (LOS) and non line of sight (NLOS) using finite element method (FEM) simulations at 2.4GHz. It was clear that the door status has a more significant effect on the signal strength in the LOS scenario, whereas the door status has a small effect on the signal propagation in the NLOS scenario. The effect of human body on wireless signals in an indoor environment has been investigated. It has been reported that the strength of the electric field distribution through a wall obstacle is higher than when it passes through people [9]. Also, the influence of human movement on wireless sensor networks in indoor radio propagation has been studied in [10 -12] and it was concluded that the electric field is significantly affected by the number of people and their mobility in the rooms. The signal level is decreased in case of slow speed movement but the trend at slow and medium speeds have the same effect as the number of people is increased. In this paper, the electric field (E-field) strength of a dipole antenna transmitter operating at 2.4 GHz in different locations within a Victorian terraced house has been investigated. Simulations were performed using the electromagnetic simulation tool FEKO [13]. Several scenarios were investigated to address the critical factors in the positioning of smart meters. E-field distributions of the ground floor, comprising a kitchen and front room have been analyzed for different occupancy scenarios. II. S