Accurate navigation and localisation information is already seen to be providing great added value for emerging mobile services. The commercial importance of location-based services (LBS) can already be seen, and is forecast to grow substantially over the coming years. The wide coverage and low cost of GPS systems have been critical to this. However, where GPS systems are unavailable (e.g. indoors or urban canyons) or provide insufficient accuracy, the potential for LBS remains relatively untapped. FIONA aims to address some of these issues by developing a modular, accessible framework to support the core functions of localisation and navigation in indoor and outdoor areas as well as facilitate the development of applications and services to be built upon it.