The risk of coexistence problems between DAB and DVB-T2 and military services at the 225–240 MHz band

In Sweden, Digital Audio Broadcast (DAB) for radio broadcasts is allocated to the frequency band of 225–240 MHz. Recently, also television broadcasts based on the standard Digital Video Broadcasting - Terrestrial, version 2, (DVB-T2) has been proposed to use the frequency band of 225–230 MHz. Since this is the lower part of the harmonized military band intended for military radio systems, there may be a risk of interference issues between DAB, DVB-T2 and military systems planned for 225–400 MHz. For example, Have Quick II (HQII) and Saturn are two military radio systems that are allocated to this band. In this work, an analysis is performed whether the military systems HQII and Saturn can coexist with DAB and DVB-T2 without performance degradation of the civilian systems. The influence is quantified in terms of the necessary distance, which is a safety distance between the civil system and the military system. Safety distances of tens of kilometers are achieved for the land scenario. For the air scenario, it is stated that the required safety distance is, in some cases, exceeds the so-called line-of-sight (LOS) distance.