10,496 research outputs found
Competitive Assessments for HAP Delivery of Mobile Services in Emerging Countries
In recent years, network deployment based on High Altitude Platforms (HAPs)
has gained momentum through several initiatives where air vehicles and
telecommunications payloads have been adapted and refined, resulting in more
efficient and less expensive platforms. In this paper, we study HAP as an
alternative or complementary fast-evolving technology to provide mobile
services in rural areas of emerging countries, where business models need to be
carefully tailored to the reality of their related markets. In these large
areas with low user density, mobile services uptake is likely to be slowed by a
service profitability which is in turn limited by a relatively low average
revenue per user. Through three architectures enabling different business roles
and using different terrestrial, HAP and satellite backhaul solutions, we
devise how to use in an efficient and profitable fashion these multi-purpose
aerial platforms, in complement to existing access and backhauling satellite or
terrestrial technologies
Improving the system capacity of broadband services using multiple high-altitude platforms
A method of significantly improving the capacity of high-altitude platform (HAP) communications networks operating in the millimeter-wave bands is presented. It is shown how constellations of HAPs can share a common frequency allocation by exploiting the directionality of the user antenna. The system capacity of such constellations is critically affected by the minimum angular separation of the HAPs and the sidelobe level of the user antenna. For typical antenna beamwidths of approximately 5/spl deg/ an inter-HAP spacing of 4 km is sufficient to deliver optimum performance. The aggregate bandwidth efficiency is evaluated, both theoretically using the Shannon equation, and using practical modulation and coding schemes, for multiple HAP configurations delivering either single or multiple cells. For the user antenna beamwidths used, it is shown that capacity increases are commensurate with the increase in the number of platforms, up to 10 HAPs. For increases beyond this the choice of constellation strategy becomes increasingly important
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