In-building insulation's impact on RF propagation

Professor Richard Langley, head of the Communications Research Group at the University of Sheffield, began the session by presenting the work his team has done as part of the Wireless Friendly Energy Efficient Buildings (WiFEEB) project. He highlights the need to factor in human occupants when modelling or designing buildings for wireless coverage, given the way we ab- sorb signals. As part of the project, he and his team looked at how well signals propagate in a typical Victorian house from a smart meter perspective. One of the key findings was that coverage fell as the frequency used increased. In his view systems such as Zigbee operating at 2.4 GHz “made life difficult for themselves, as these aren’t high data rate systems”.

Langley also explored the use of frequency selective surfaces (FSS) and intelligent wall units (IWUs) to create a smart environment “that we can change dynamically”, like a conference centre. FSS are printed panels with a window made up of a printed circuit board that switches between reflecting and transmitting the signal. However, he explains that the attenuation they can produce is only 20 dB and for many signals that isn’t enough. IWUs are easy to design, much cheaper than FSS and can do multi-band very easily. They consist of a receiving antenna, a filter, an amplifier and a transmitting antenna.