Occupancy measurements of the short-wave spectrum around 7.1 MHz over one week

Due to time and location dependent propagation conditions, the occupancy of the short-wave spectrum is highly dynamic. To enable a reliable connection over the short-wave spectrum, Automatic Link Establishment (ALE) communication systems were developed in the past decades. Current systems typically rely on either MIL-STD-188-141 or STANAG 4538 standards and communicate over a finite set of channels, each with of 3 kHz bandwidth. As partially provided by the MIL-STD-188-110C standard, next generation short-wave communication systems adaptively allocate the utilized channel bandwidth. In order to provide data sets with realistic test scenarios for the performance evaluation of such systems, knowledge of the occupancy of the short-wave spectrum is required. For this reason, we performed spectrum measurements in Germany over one week. Here, the spectrum around 7.1 MHz was captured over a bandwidth of 500 kHz. To characterize the channel occupancy and statistical properties, such as individual occupancy lengths and their packet distance time, a signal processing chain was developed. We present our measurement setup and the subsequent signal processing chain. Furthermore, we provide first results on the time dependency of the channel occupancy as well as more detailed occupancy statistics.