This paper contains a review of technologies, theoretical studies for optical communications from and to high-altitude platforms (HAPs). We discuss how to use optical communication to transmit data at multi-Gigabits in HAP to HAP and HAP to Satellite. The influence of the atmosphere, background light and other noise are discussed in this paper, we explain the advantages and disadvantages of free-space optical communications. And the performance of HAPs (High Altitudes Platforms) WiMAX is studied for different HAPs heighth and transmitted power level in different transmission format. The coverage radius increases with the transmitted power increment and with the operating frequency reduction
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.