Mobile Communication Measurements Along Railroads and Model Evaluations Over Eastern-Indian Rural Regions

Abstract

Establishing models for developing radio-planning tools that will be utilized to design new mobile networks for public safety, emergency communications, and public transportation (such as railways) is an essential component of system design. Field-strength measurements were conducted in the rural eastern part of India in a moving train along the railroads, In the UHF band. This was done to identify suitable models for various rural zones of India along railroads, and to evaluate the suitability of existing models. Various models were tested with the data, and the standard deviations of the prediction errors were determined. For a given base station, the standard deviations of all the methods varied by 2 dB to 3 dB. The lowest standard deviations for all the base stations were seen in the Irregular Terrain Method (ITM), followed by Hata's Method for open regions. Path-loss exponents were derived, and were found to vary between two to three in low-density scattered environments. In rocky and hilly environments, the values shot up to more than six. The study also showed that numerical electromagnetic codes can be used to predict the path loss over any ground with relatively good accuracy, as their predictions agreed with experimental results.