Long-range mobile communication over sea utilizing evaporation duct

High-speed wireless communication over sea is either limited due to the lack of tall infrastructure on sea to provide line-of-sight (LOS) based microwave communication or because the cellular network on land is unable to extend connectivity over vast sea area beyond LOS. Evaporation duct has very high percentage of occurrence in the tropical regions of the World such as Malaysia. If a signal is trapped in the evaporation duct, it can propagate beyond the horizon, achieving long-range distances with very less attenuation. Where many researchers have explored fixed point-to-point (PTP) signal propagation utilizing evaporation duct, we have performed experiment to show that a link between a fixed transmitter on land and a mobile receiver on boat can be established over sea. Statistical analysis of measured received signal level (RSL) on a mobile boat is shown for up to 64km distance, which is beyond LOS considering a very low height of the receiver antenna. Pathloss exponent is calculated and factors affecting mobile communication over sea are also discussed. Using pathloss exponent, simplified model pathloss is determined and compared with average measured pathloss, free space and parabolic equation based pathloss.