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Modelling the likelihood of line-of-sight for air-to-ground radio propagation in urban environments

Research output: Contribution to journalArticle

Original languageEnglish
Number of pages5
JournalIEEE Global Telecommunications Conference, 2006 (GLOBECOM '06)
StatePublished - Nov 2006
EventGlobal Telecommunications Conference, 2006 (GLOBECOM 2006) - San Francisco, United States


The likelihood of line-of-sight (LoS) is an essential component in any radio channel model. It is particularly useful for radio network planning and urban coverage prediction. Empirical LoS models are hard to derive due to a strong dependency on local topology and the need for large measurement datasets. Since buildings are the major obstructions in a dense urban environment, we propose a new theoretical model to determine the LoS probability for air-to-ground channels based on local building geometry and knife-edge diffraction theory. The model takes into account key statistical parameters such as building height, building size, building coverage, street width and street angle distribution. The theoretical model is shown to agree well with ray tracing simulation results. The statistical parameters, such as mean building height, percentage of area covered by buildings (building coverage) and building density, can all be easily obtained for a specific location. We also derive equations for the likelihood of LoS for a direct slant path. These equations can be used in the analysis of air-to-ground channels.

Additional information

Publisher: Institute of Electrical and Electronics Engineers, Inc. (IEEE) Name and Venue of Conference: IEEE Global Telecommunications Conference, 2006 (GLOBECOM '06), San Francisco Name and Venue of Event: IEEE Global Telecommunications Conference, 2006 (GLOBECOM '06) Rose publication type: Conference contribution Terms of use: Copyright © 2006 IEEE. Reprinted from IEEE Global Telecommunications Conference, 2006 (GLOBECOM '06). This material is posted here with permission of the IEEE. Such permission of the IEEE does not in any way imply IEEE endorsement of any of the University of Bristol's products or services. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to By choosing to view this document, you agree to all provisions of the copyright laws protecting it.

    Research areas

  • radio channel model, likelihood of line-of-sight, Fresnel zone, knife-edge diffraction, air-to-ground, urban


Global Telecommunications Conference, 2006 (GLOBECOM 2006)

Duration1 Nov 2006 → …
CitySan Francisco
CountryUnited States

Event: Conference

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