A study of frequency selective multipath fading on an 8-GHz, 135.6-km overwater digital microwave path

Preliminary results of an ongoing study of a 135.6-km overwater path (Seburiyama, Japan to the Tsushima repeater with 106.4-km link from Tsushima to Changsan, Korea) showing the effects of severe reflective multipath and excess path clearance are presented. The results of five months of test results are covered. The path performance is monitored by the use of a computer-aided data acquisition system. The ability of existing path unavailability equations to be extrapolated to much greater distances or their use with paths traversing highly reflecting terrain is questionable. Although the test results from this system cover a small period of time to establish definitive prediction techniques, the test results from this system cover a small period of time to establish definitive prediction techniques, the test results show that distinctly different types of fading are occurring on this path and the resulting unavailability is greater than predicted using present techniques.<
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