Analysis of the effect of waves on the stability of TDMA based marine long range Wi-Fi backhaul links

A cost-effective marine communication network infrastructure to provide internet access to fishermen as far away as 60 km from the shore has been designed and developed by our research centre. The marine communication infrastructure is based on Long Range Wi-Fi technology for backhaul with an onshore base station situated on top of a tall structure and client stations and mobile base stations on the boats. Standard Wi-Fi network is used for access so that the fishermen can connect to the network using the smart phones and tablets they own already. This paper presents the study of the impact of the rocking movements of the boat caused by the waves on the stability of the backhaul links in this network. The study is done on the basis of data collected during several field trials conducted over the Arabian Sea in Kerala. The wave motion effects for the different planes corresponding to pitch and roll have been calculated from the collected data. Different statistical parameters like mean, median, standard deviation, etc., have been computed for the data sets obtained and correlation of the computed data with parameters such as received signal strength, transmission rates and the sea states has been done. This will lead to better understanding of the extent of misalignment between the antennas on the boat and the base station due to rocking movements of the boat triggered by the waves and its effect on the deterioration of backhaul link quality.