This work describes the implementation of a tool for simulating wireless communication networks, considering the characteristics of radio wave propagation near the sea surface. The tool is an extension of the ns-3 Network Simulator and supports two propagation

loss models: Two Ray Maritime Model, which models the reflection effects of electromag- netic waves on the sea surface; and Three Ray Maritime Model, which additionally models the effects of refraction of electromagnetic waves due to the existence of evaporation ducts in the troposphere. As the Three Ray Maritime Model has the height of the evaporation duct as a parameter, a model was also implemented to estimate that height based on climatic conditions. The propagation models implemented consider a line of sight between the transmitter and receiver antennas.

With the described tool, we show how, in some situations, under different evaporation duct heights, the radio signal loss related to the increase in distance between transmitter and receiver is less than that predicted by some propagation loss models which do not consider the existence of these ducts. This reinforcement of the received signal caused by the existence of the evaporation duct can be considered positive, as it might extend the network coverage, or negative, in the sense that, as the signal travels longer distances, interference may occur between stations that operate at the same frequency. Hence the need to model these effects due to the current context of growing interest in wireless marine communications to support different types of applications, such as surveillance, security and ecological monitoring.

The extension of ns-3 is of particular importance, as it is one of the most used simulators to design and evaluate communication networks.