Multiple HAP Networks
David Grace, Mihael Mohorčič · 2010
High altitude platforms (HAPs) could offer a higher spectral efficiency than GEO satellites, some scepticism remains over whether HAPs can approach the spectral efficiency of terrestrially based broadband wireless communications. This is based on the assumption that a cellular approach is used with the minimum cell size being limited by the maximum size of the antenna payload that can be accommodated on the HAP. This chapter illustrates that it is possible to exploit one feature that has been largely overlooked, the fact that user antennas may also be highly directive. This allows spatial discrimination between multiple HAPs located in different parts of the sky, thereby permitting them to share a common spectrum. This chapter illustrates the main factors affecting the performance of multiple HAP constellations. After the discussion regarding the constraints of the two-ring constellations, the chapter describes the constellation design strategies. Controlled Vocabulary Terms aircraft antennas; broadband communication; wireless communication