Groundbreaking research undertaken by the Queensland University of Technology has led to the creation of systems that can detect invisible intruders on wireless local area networks.

QUT Information Security Institute co-researcher Dr Jason Smith said he and a colleague had invented an effective system to detect unwanted presence on wireless networks.

"Unlike a building, there are no clearly defined boundaries to wireless networks. The perimeter of a network is defined by the quality of the receiving antenna," Dr Smith said.