HIGH ALTITUDE PLATFORMS FOR WIRELESS COMMUNICATIONS: FROM THEORY TO PRACTICE
Since 2001, scientists have been working on issues related to high altitude flights, which permitted to devise various applications and solutions*, among which is wireless communication. Currently, important actors are massively investing in these technologies related to technical, economic and human issues. A global Earth coverage would allow to connect 4 billion human beings left aside or improperly covered by current solutions, mainly for infrastructure costs reasons.
New projects are making their way currently, leveraging solutions based on low altitude satellites (between 20km and 2000km whereas geostationary satellites are at 35 786km orbits), offering global Earth coverage. Among these projects : SpaceX**, supported by Elon Musk with Google and Fidelity, sees to launch into orbit 4000 satellites at 600km altitude between 2022 and 2030; OneWeb, supported by Richard Branson (with Virgin, Qualcomm, Airbus, the Indian Bharti Entreprises, Hugues Network, Intelsat and Coca-Cola), wants to deploy, before 2019, 648 satellites at 1200 km altitude by leveraging LTE, 3G and WIFI technologies; Google Loon, a project based on 100 days lifespan balloons launched between 10km and 60km from Earth (stratosphere) and leveraging 4G/LTE technologies; Samsung** is designing a constellation of 4600 satellites 1500km from Earth using 5G networks; Facebook, with its Aquila project based on a solar-powered drone able to fly for 3 months, for more limited applications (providing internet access in a 80km area) etc.
All these projects would allow building nearly universal communication devices, but also to offer solutions in case of natural disasters affecting ground infrastructures, or to contribute to airline coverage. The first practical implementations would give an empirical feedback, since some questions are already arising, and their answers will play a key role in simulation and testing solutions. For instance, what happens with magnetic storms and their impact in the stratosphere on these flying objects? How to model a network of permanently moving antennas (Vs. Current network of static antennas)? Conventional carriers are aiming to offer a 99.999% availability quality of service, can balloons or satellites offer the same level of service? Will backbone networks be located on a balloon or a satellite, or on the ground as currently, which would mean a big change for testing procedures based on optical fiber and traditional schemes applied currently. Propagation and traffic management models used currently rely on operational feedback. The first altitude solution deployments will allow quickly reaching this new field “from theory to practice”
**http://motherboard.vice.com/read/spacex-warns-paper-satellites-could-disrupt-its-space-internet-plan
