# State of the Art of Telecommunication Systems in Isolated and Constrained Areas
## 5 The Tethered Balloon Solution  
### Description of the Captive Balloon  
The comparative study shows that a flying solution based on captive tethered balloons [79] can be the best to implement a telecommunication system in an isolated and constrained environment like Northern Quebec. The solutions developed by Google (Google Loon) and Thales (Stratobus) require significant human resources with teams managing the balloon's development, teams taking charge of the launch, and finally, a team monitoring the flight of the balloon in a control room. Under these conditions, the cost of such a solution quickly becomes an obstacle when one wishes to implement a telecommunication system in a localized environment and with reduced budgets compared to the millions of dollars spent by Google and Thales. These solutions are so attractive in terms of radio coverage and in terms of energy autonomy, all associated with good performance; therefore, a more modest solution with captive balloons becomes very interesting. The tethered balloon (Figure 14) has a \"wire at its leg\" linking it to the ground. Photovoltaic panels fit the balloon envelope. Thus, the solar energy captured is converted into  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & **Electrical** & **Acclimatization Depending** & **Radio** & **Cost of the** & **Deployment** \\  & **Supply** & **on Weather Conditions** & **Coverage** & **System** & **Time** \\ \hline Telecommunication & & & & & \\ towers & C & B & B & D & D \\ \hline Optical fiber & C & A & C & E & E \\ \hline The balloons & A & C & A & B & B \\ \hline The drones & D & E & B & B & A \\ \hline \hline \end{tabular}
\end{table}
Table 2: Summary comparison of telecommunication system solutions in isolated areas and constraint environment (A is the best solution, and E is the worst solution).  
Figure 13: Deployment of Google Loon before launching [78].  
electrical energy and sent to the ground to charge the batteries that supply the balloon's onboard telecommunication system. An intelligent control system ensures the balloon's stability in flight during strong wind conditions. The balloon's height can be around 90 m depending on the results obtained in the simulation (RadioMobile software) to size the telecommunication system. A fleet of balloons is deployed to obtain telecommunication coverage for an isolated sector. The balloons will communicate with each other thanks to their onboard telecommunication system (Figure 15). If one of the balloons is connected to the Internet by optical fiber, then all the balloons have the Internet. We can, therefore, imagine disseminating sensors [80] on the isolated site.  
This telecommunication structure will initially allow data from sensors located in the isolated sector to be pushed into the \"Cloud\" [81], thus enabling remote monitoring of the isolated sector accompanied by SMS or email alerts if necessary. The sensors can be for environmental applications to prevent a climatic disaster or allow the geolocation of individuals who might need assistance. In the same vein, this monitoring could apply to industrial processes on railroads or in mines. Then, in the case of trains, it would be possible to follow at a distance the trains operating in isolated areas and for mining companies to remotely monitor their industrial processes. Therefore, we will have deployed the Internet of Things [82; 83] in an isolated environment. This solution has the advantage of being mobile because it can be deployed in a short time.  
Figure 14: Illustration of the telecommunication balloon.  
However, to withstand strong winds, the cables connecting the balloon to the ground will be controlled by an intelligent control system, fed by data from a mini meteorological station embarked on the balloon, as in Figure 16.