The Guardian newspaper reports about a new technology enables entire rooms to be sealed off from mobile phone signals using frequency-selective "wallpaper" screens (FSS) on a large scale. The breakthrough was made by QinetiQ and its screens are metal grids designed in an intricate pattern which filter out some radio signals and allow others through, depending on their wavelength. They can be fitted to walls and covered with real wallpaper.

Mobile phone or WiFi signals are effectively blocked out but two-way radio and other similar systems are totally unaffected, it said.