## 3 Survey Results
### Communication Media  
Used communication media characteristics are listed in Table 9.  
### Communication Media  
Used communication media characteristics are listed in Table 9.  
\begin{table}
\begin{tabular}{c l c c c} \hline \hline
**Nr** & **Codename** & **Communication media** & **Used channels** & **Directionality used** \\ \hline
1 & Habitats & radio over air & 1 & n \\
2 & Minefield & radio over air + sound over air &? & n \\
3 & Battlefield & radio over air & 1 & n \\
4 & Line in the sand & radio over air & 1 & n \\
5 & Counter-sniper & radio over air & 1 & n \\
6 & Electro-shepherd & radio over air &? & n \\
7 & Virtual fences & radio over air & 2 & y \\
8 & Oil tanker & radio over air & 79 & n \\
9 & Enemy vehicles & radio over air & 1 & n \\
10 & Trove game & radio over air & 1 & n \\
11 & Elder RFID & radio over air & 1 & n \\
12 & Murphy potatoes & radio over air & 1 & n \\
13 & Firewxnet & radio over air & 1 & y, gateways \\
14 & AlarmNet & radio over air & 1 & n \\
15 & Ecuador Volcano & radio over air & 1 & y \\ \hline \hline \end{tabular}
\end{table}
Table 9: Deployments: communication media.  
Figure 6: **Deployment network connectivity—Eighty percent of deployments consider a network to be continuously connected, while only 12% experience significant disconnections and 8% use opportunistic communication.**  
With few exceptions, the communication is performed by transmitting radio signals over air. Ultrasound is used as an alternative. Some networks may use available wired infrastructure.  
Eighty-five percent of applications use one, static radio channel; the remaining 15% do switch between multiple alternative channels. If radio channel switching is complex and code-consuming, it should be optional at the OS level.  
While directionality usage for extended coverage and energy efficiency has been a widely discussed topic, the ideas are seldom used in practice. Only 10% of deployments use radio directionality benefits, and none of these deployments utilize electronically switchable antennas capable of adjusting directionality in real time [72]. A directionality switching interface is optional; users may implement it in the application layer as needed.  
\begin{table}
\begin{tabular}{l l c c c} \hline \hline
**Nr** & **Codename** & **Communication media** & **Used channels** & **Directionality used** \\ \hline
16 & Pet game & radio over air & 1 & n \\
17 & Plug & radio over air &? & n \\
18 & B-Live & wire mixed with radio over air &? & n \\
19 & Biomotion & radio over air & 1 & n \\
20 & AID-N & radio over air & 1 & n \\
21 & Firefighting & radio over air & 4 & n \\
22 & Rehabil & radio over air & 1? & n \\
23 & CargoNet & radio over air & 1 & n \\
24 & Fence monitor & radio over air & 1 & n \\
25 & BikeNet & radio over air & 1 & n \\
26 & BriMon & radio over air & 16 & n \\
27 & IP net & radio over air & 1 & n \\
28 & Smart home & radio over air & 16 &? \\
29 & SVATS & radio over air &? & n \\
30 & Hitchhiker & radio over air & 1 & n \\
31 & Daily morning & radio over air & 1 & n \\
32 & Heritage & radio over air & 1 & n \\
33 & AC meter & radio over air & 1 & n \\
34 & Coal mine & radio over air & 1 & n \\
35 & ITS & radio over air & 1 & n \\
36 & Underwater & ultra-sound over water & 1 & n \\
37 & PipeProbe & radio over air and water & 1 & n \\
38 & Badgers & radio over air &? & n \\
39 & Helens volcano & radio over air & 1? & y \\
40 & Tunnels & radio over air & 2 & n \\ \hline \hline \end{tabular}
\end{table}
Table 9: _Cont._