A New Propagation Path-Loss Prediction Model for Military Mobile Access

The Longley-Rice propagation path-loss prediction model,1,2 developed by the National Telecommunications and Information Administration (NTIA) mainly for troposcatter transmission and long-range line-of-sight transmission, has often been suitable for ground mobile radio propagation by adding an adjustment factor for urban areas. Since the model was not originally developed for a mobile radio environment, it does not provide a desired mean value which should match experimental values to a standard deviation of 8 dB. Okumura's model,3 obtained from empirical data gathered in the Tokyo area, has been used for commercial mobile radio because this model was designed specifically for the mobile radio environment. Although it is not a proper model for predicting the propagation path-loss in the United States, most measured values are within 8 dB of the mean predicted value. This paper introduces a model which predicts the actual measured value is within a standard deviation of 3 dB instead of 8 dB from the predicted value. A more accurate prediction of path loss can enhance a military system's performance. In the military environment set of base station sites must be properly chosen to allow optimum connectivity for tactical mobile radio communications. This model provides such information. Each time the base station is removed to a new site, this model can be used to select a new optimum site based upon the battlefield condition.