## 2 Digital Radio Market  
The DAB+ system, successor of the Eureka 147 DAB project, is one of the leading broadcasting standards. It provides high-quality digital terrestrial services for both fixed and portable devices, including fast-moving objects, e.g., trains or cars up to 200 km/h. It can operate in either MFN (Multiple Frequency Network) or SFN (Single Frequency Network) mode [6; 7]. This standard also enables stable reception conditions in case of highly populated dense urban areas [8; 9]. The DAB/DAB+ system can be manufactured and/or utilized by any interested third party. Moreover, as a digital broadcasting system, it is more bandwidth (spectrum) efficient, and offers several advantages over traditional analog systems, e.g., higher sound quality compared to FM radio, of course, at the appropriate bitrate. This multimedia content distribution standard is highly supported by the WorldDAB forum, which provides various information on its development [10]. Table 1 describes the percentage of population covered by the digital signal in the top five European countries. As shown, the leaders in digitizing radio reached almost full coverage, considering the number of inhabitants in particular countries. One must note, however, that this does not \begin{table}
\begin{tabular}{c c} \hline \hline
**Country** & **Percentage (\%)** \\ \hline Denmark & 99.9 \\ Norway & 99.7 \\ Switzerland & 99.5 \\ Germany & 98 \\ UK & 97.3 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Network coverage of DAB+ (as a percentage of population). mean that each and every citizen consumes this digital content. The household penetration of DAB/DAB+ receivers among the top five European markets is described in Table 2.  
It should be mentioned that most devices are hybrid ones enabling the consumption of analog FM and digital DAB/DAB+ radio as well as a number of internet streaming services, not to mention Bluetooth compatibility with wireless devices such as smartphones, tablets, or headphones. One should take into account that the car industry has a profound impact on the popularity and number of sold consumer devices. On the other hand, many people listen to radio while driving to work or home. Table 3 describes the percentage of new cars sold with integrated DAB/DAB+ radio among the top five European countries. Potentially, each newly bought car most often has DAB/DAB+ compatibilities built in. It only requires a license and/or additional configuration. A service may be viewed as popular or valuable only if it fulfills the needs and expectations of end users and whether it matches the taste of each target group and/or individual. Table 4 describes the popularity of DAB/DAB+ among the top five European radio markets. As shown, Norway performed a total switchover from analog to digital radio, whereas other countries are trying to establish balance between FM and DAB/DAB+ radio. It is worth mentioning that Switzerland will not resign from analog broadcasting in order to distribute content to serve the local community in particular cantons. In case of DAB+, all services are grouped in the so-called ensemble. The number of offered services, including traditional radio programs as well as additional data services, related with allocated resources (bitrate) can be easily arranged. Thanks to this, the ensemble can be flexibly reconfigured in order to test the best settings that will meet user demands. Other countries from outside the European Union are also making investments \begin{table}
\begin{tabular}{c c c} \hline \hline
**Country** & **No. of FM Stations** & **No. of DAB+ Stations** \\ \hline Norway & 0 & 32 \\ Switzerland & 54 & 70 \\ Belgium & 29 & 55 \\ UK & 6 & 50 \\ Italy & 21 & 50 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Number of national stations in FM and DAB+. \begin{table}
\begin{tabular}{c c} \hline \hline
**Country** & **Percentage (\%)** \\ \hline UK & 67 \\ Denmark & 34 \\ Germany & 25 \\ Netherlands & 24 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Household penetration of DAB+ receivers.