USRP based HF spectrum occupancy measurements at two locations in central and Western Romania

In this paper, measurements of the spectral occupancy in some high frequency (HF) bands in the Western part of Romania are presented. Signals have been acquisitioned by means of an Universal Software Radio Peripheral (USRP) equipment and spectrum occupancy values have been calculated off-line for a set of frequency bands that present interest for establishing of a system for emergency communications. Calculations have been based on an energy detection criterion that is presented and discussed in the paper. Preliminary measurements performed simultaneously at two different locations, namely in Sibiu and Timişoara cities, Romania, are also reported and compared.