Buoy-to-ship experimental measurements over sea at 5.8 GHz near urban environments

Current marine wireless communication systems used for monitoring applications based on buoys suffer from lots of weakness. Many research works concern the design and development of new technological applications to improve marine communications. Particularly, a wireless communication system based on WiMAX standard at the 5.8 GHz band (license-exempt band) could be a good candidate. As an initial task, a propagation channel measurement campaign in maritime environments was carried out to investigate the impact of the wireless channel in different situations. This work provides large scale path loss measurements over sea around urban environments. In particular, a radio link between a buoy and a ship at 5.8 GHz is studied. NLOS (Non-Line-Of-Sight) paths are investigated in depth and they are compared to LOS (Line-Of-Sight) paths. The designed measurement system is described and the experimental measurements are shown. An empirical model is obtained using these experimental data and the key wireless channel parameters are analyzed. In addition, the empirical model is compared to the free space and two-ray theoretical models. This investigation is useful, among others, for planning Worldwide Interoperability for Microwave Access (WiMAX) networks offshore around these challenge environments.