# State of the Art of Telecommunication Systems in Isolated and Constrained Areas
## 3 Comparison of the Solutions
### Criteria for Comparing Solutions
#### 3.1.2 Adjustment of the Telecommunication System to Weather Conditions  
The second criterion is closely linked to the weather conditions prevailing at the location of the telecommunication system. The system must indeed evolve in an environment constrained by the cold, which characterizes Northern Quebec. Therefore, the system has to be resistant to very low temperatures [70]. This constraint constitutes an important parameter because below \(-40\)\({}^{\circ}\)C, the electronic devices' operating limits are reached. It will be necessary, for example, to demonstrate expertise and, above all, a lot of experience to prevent the temperature from reaching this fateful threshold inside the cases (transmitters, receivers) containing the electronic devices. For example, solutions using heating wires should be implemented inside the casings. However, no solution is perfect. The heating system requires more energy from the system's power supply. Another meteorological criterion that has an impact on the telecommunication system in an isolated environment is the wind. Indeed, the telecommunication system makes it possible to reach significant distances when the antennas are high up where the winds are the strongest. The signal's  
Figure 11: Vertically oriented PV [51].  
reflections on the ground and obstacles, such as trees, are reduced at higher altitudes. The reflection of the signal transmitted on the ground (\"ground reflection\") [71] generates a division by 4 of the distance of the couple transmitter-receiver in the transmission of Hertzian information. Therefore, the telecommunication system, at higher heights, faces strong wind resistance. Here again, the drones show their great weakness in deploying a telecommunication system. The strong wind is an enemy of the drone since it can nail it to the ground. Regarding the balloon solution for the deployment of a telecommunication system, the wind is also problematic. However, Loon balloons have been able to operate with winds of the order of 291 km/h in the stratosphere. The structure of the materials used to produce the balloon's envelope [72] makes it possible to withstand excessively low temperatures. In general, a balloon's envelope is built of several beams arranged like vertical strips [73]. All the beams (Figure 12) meet at the balloon's north and south poles, thus constituting the balloon's envelope. The spindles, just a few centimeters wide, consist of a complex of three thin films.  
Most of the time, the first layer is polyethylene terephthalate (PET), about ten micrometers thick; the second layer consists of a polyamide 6.6 (PA) film twice the width of the first; and finally, a third layer consists of a PET film a few tens of micrometers thick. The spindles between the north and south points of convergence of the balloon are thermoglued. The amount of helium injected into the balloon shortly before launch depends on the duration of the mission. The latter is intimately linked to the leakage of helium through the beams during the flight. For tethered balloons, if the photovoltaic structure is placed on the canopy, it would inevitably be covered for a more extended period than a fixed vertical orientation, as in the case of telecommunications towers.  
On the other hand, telecommunication towers are a very good solution to resist strong winds and excessively low temperatures. Optical fiber is even more interesting, and it is the best solution since it is buried and, therefore, does not suffer the disadvantages of winds. At each point of the fiber where the access terminals or simply the repeaters are located, the photovoltaic entities for their power supply do not have dimensions that put them at risk in high winds.