A personal radiation level monitoring system has been developed based on an autonomous, advanced personal dosimeter. This dosimeter uses a scintillator-SiPM combination for the radiation detection, it integrates spectroscopy and isotope identification capabilities. In order to choose the optimum scintillator crystal and photosensor for a portable gamma dosimeter, several tests on energy resolution and internal activity were performed. We have chosen a 9x9x20mm3 CsI:Tl crystal and a 50
M SiPM. All measurements are time and location stamped, even for indoor locations. The system implements Wireless Sensor Networks access in such a way that several networked personal dosimeters can be considered mobile sensors providing a high sampling rate over an extended area. The system developed is modular, it consists of three elements: the Personal Dosimeters, a Wireless Gateway deployment and a web-based remote storage, monitoring and management system, named Central System.