Wideband HF and 4G ALE Near Vertical Incidence Skywave Test Results

This paper examines the results of Wideband High Frequency (WBHF) Near Vertical Incidence Skywave (NVIS) Over-The-Air (OTA) testing conducted in the upper Midwest region of the United States of America (USA). Two distances, 45 miles and 180 miles, were used for evaluating data throughput performance over very short and typical distance NVIS links. Two separate trials were conducted, one in early summer, another in the autumn of 2014 for capturing diverse seasonal performance characteristics. A prototype implementation of a WBHF Automatic Link Establishment (ALE) protocol serves as the frequency, bandwidth, and data rate selection function for HF channels ranging from 3 kHz to 48 kHz wide. Several performance metrics were collected from each campaign for seasonal and geographical diverse comparisons.