George A. Hufford, William A. Kissick, Anita G. Longley, and Harold T. Dougherty

Abstract: Although the use of transmissions that are composed of bursts of information is not new, its application in a terrestrial environment at VHF and UHF is. The usual way of expressing the variabilities in received signal level due to propagation effects for the design of conventional telecommunication systems is inadequate for burst transmission. Instead of using time and location variability, the concept of "waiting distance" is introduced and its magnitude is estimated. The waiting distance represents how far one terminal probably must move to have reached a favorable location where a transmitted burst will be successfully received. Acceptance of the waiting distance is a trade–off to achieve an extended range or a power advantage. This report first examines the concepts of a burst transmission system in the context of using the location variability to estimate the waiting distance, and the associated range extension, in terms of the correlation distance of the received signal level. Using this theory and both previous and current measurements the correlation distance is estimated and, hence, so is the waiting distance. The estimates of the correlation distance range from 200 to 800 m. Recommendations for future efforts are proposed.

Keywords: radio propagation; terrain; VHF; UHF; burst transmission; variability

Disclaimer: Certain commercial equipment, components, and software may be identified in this report to specify adequately the technical aspects of the reported results. In no case does such identification imply recommendation or endorsement by the National Telecommunications and Information Administration, nor does it imply that the equipment or software identified is necessarily the best available for the particular application or uses.

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