The expected technological development, mostly found in the communication domain, will accordingly increase the number of artificial electromagnetic field (EMF) sources, as well as corresponding EMF exposure in the environment. Thus, EMF monitoring has been required worldwide and some innovative monitoring systems are being developed. Some of them are intended to simultaneously perform long-term monitoring and exposure assessment, as well as to timely inform the public on present EMF levels. The Serbian Electromagnetic Field Monitoring Network – SEMONT is one of such systems which has been activated recently. Considering the diversity of the existing EMF sources, as well as the opinion of the public that base stations generally contribute to the increased EMF level, the SEMONT system was designed to perform monitoring of the high-frequency electric field strength in four bands. First, in a wideband, from 100 kHz to 3 GHz, it observes the field strength from all local sources, and then in three sub-ranges of GSM 900, GSM 1800 and UMTS 2100, using the modern quad-band Narda AMB 8057/03 sensor station. In this paper, the SEMONT’s database support for the quad-band sensor utilization, as well as the results of initial in situ monitoring, have been presented. Regarding the test location, the acquired field strength results in all bands appear to be far below the Serbian prescribed reference levels.