This Information Paper provides an introduction to radio-based or 'wireless' fire detection systems. It discusses the principles of operation and typical wireless fire detection components and systems that are commercially available, and highlights their unique advantages and disadvantages in relation to conventional hardwired systems. Finally, it summarises compliance issues for wireless components with particular emphasis on requirements from European Directives. 6 pages Contents Operating principle -The radio module -The antenna Typical system components and system configurations Advantages of wireless systems Disadvantages of wireless systems Typical applications European regulatory framework EN 54-25 References