Personal and first-responder positioning: State of the art and future trends

Current forecasts predict growing cities and increasingly complex building structures in the future. Hence, accurate and reliable positioning in urban areas is required for novel personal Location Based Services (LBS) as well as for efficient first-responder services. Currently, the Global Positioning System (GPS) is used for positioning whenever possible, since it is globally available and cost-effective. The major drawbacks of GPS-based positioning systems in urban areas are signal attenuation as well as non-line-of-sight (NLOS) multipath signal propagation. Hence, the required accuracy and reliability are often not achieved. Unfortunately, other semi-autonomous positioning systems beside GPS are at present not fully operational in real personal and first-responder positioning scenarios. Therefore, in this paper positioning subsystems as well as methods for the integration of complementary subsystems are reviewed. Thereafter, based on this review as well as on related work of other research groups, two integrated positioning system architectures are proposed, assessed and discussed. It is shown that personal and first-responder positioning systems are based on different hardware and software platforms. Furthermore, the requirements regarding accuracy and reliability are different for personal and first-responder positioning. Finally, future trends in the development of technology for real personal and first-responder positioning scenarios capable systems are also discussed.