Government security guidance describes the perimeter as the physical line that defines a site and recommends controlling perimeter access points, limiting unnecessary gates and securing access out of hours. It also states that perimeter lighting should be considered alongside other security technologies.
The boundary therefore needs to work as part of a wider security arrangement. ProtectUK also recognises detection on fences and in the ground, and says more sophisticated systems can combine perimeter detection with CCTV and video motion detection.