High Altitude Platforms (HAP) are a new type of infrastructure for mobile networks which allow to extend the 4G/5G cellular coverage to low density rural area, or to provide a solution to emergency situation.
In HAP system, a 4G base station is placed on board of the nacelle of a platform - dirigible or balloon - located in the lower part of the stratosphere, at about 20 km of altitude.
Thanks to directive antennas or to beamforming exploiting multi-antennas, a cellular network may be created on the ground, with the advantage, in contrast with classical terrestrial networks, to have a centralized management of the cells and of their interferences in a single base station (on the nacelle) while a distributed network of base stations located on the ground has not this centralized management.
Balloons and stratosferic airplanes have provoked a great amount of attention in the international scientific community since the beginning or years 2000. And recently, new HAP solutions have been proposed :« Google Loon », « Facebook Aquila » or « Stratobus » by Thales https://www.thalesgroup.com/fr/monde/espace/press-release/stratobus-decolle. Those new systems enlarge the fields of applications and motivate today new research works.
HAP specificities (specific channel model, centralized communications as opposed to terrestrial communications, fixed central station as opposed to low orbit satellite communication, low delay and distance with respect to satellite communications) make the solutions designed for terrestrial or satellite communications suboptimal. However, new resource allocations algorithms have to be designed and compared in term of coverage quality and overall throughput offered to users.
Thus, this thesis aims at exploiting the advantage of HAP, taking into account its constraints (energy consumption, movement due to the wind…) in order to optimize performance and resource:
 T.C. Tozer, D. Grace, “High-altitude Platforms for Wireless Communications” IEEE Comm. Mag., June 2001.
 Fernando Ulloa-Vasquez, J.A. Delgado-Penin, “Performance Simulation of High Altitude Platforms (HAPs) Communication Systems”, Report on EC-sponsored IST Project Helinet.
 Jose Luis Cuevas-Ruiz, Jose A. Delgado, “A Statistical Switched Broadband Channel Model for HAPs Links”, IEEE Comm. Mag., March 2004.
 Fabio Dovis, Roberto Fantini, et al, “Small-scale Fading for High Altitude Platform (HAP) Propagation Channels”, IEEE Comm. Mag., April 2002
 Stratospheric Propagation And HAPs Channel Modeling, thesis submitted by Andrew Ayoola Oluseyi Olapido ,Blekinge Institute of Technology
 High Altitude Platform Stations: An Opportunity to Close the Information Gap. ITU Report on ITU Question 9/2
 Struzak R: Emergency Telecommunications with and in the Field; United Nations Office for the Coordination of Humanitarian Affairs, 2000
 Struzak R: Satellite Industries at the Turn of the Century; International Communications (the same issue)
 Thornton J, Grace D, Spillard C, Konefal T, Tozer T C: Broadband Communications from a High-altitude Platform: the European HeliNet Programme; Electronics & Communication Engineering Journal, June 2001, pp. 138-144
[10) Tozer T C, Grace D: High-altitude Platforms for Wireless Communications; Electronics & Communication Engineering Journal, June 2001, pp. 127-137
Pierre Duhamel (Pierre.Duhamel@l2s.centralesupelec.fr)
(c) GdR 720 ISIS - CNRS - 2011-2018.