Accessing current simulation count Accessing platform time and clock time Suppressing simulation progress Calculating distances between nodes Programmatically stopping a simulation Setting log level of the simulation agent Specifying relative paths for files Working with GPS coordinates Distributing nodes randomly Encoding and decoding PDUs Using MATLAB to plot results Using a visual debugger in agent development

UnetStack is bundled with the UnetIDE for developing agents. While the UnetIDE is well integrated with UnetStack, using a more feature rich IDE can be instrumental in boosting productivity when working with larger projects. In this tutorial, we will go through the steps required to create a UnetAgent using the powerful IntelliJ IDEA Java IDE.

The ease of implementation and development of applications as needed by researchers or in industry using underwater acoustic modems is crucial today. In order to realize the potential of advancements made in the underwater communication and networking technology, the applications should be easy to implement and test. Implementation of few basic operations such as transmission of packets carrying information from one node to another or transmission/recroding of signals are simple tasks using which complex useful applications/protocols can be developed. Therefore, a detailed explanation on implementation of these basic tasks in UnetStack (an underwater network stack and simulator) is presented here.

It is a common practice to attach a transponder to various underwater assets (both static and mobile) for short and long term field deployments. These transponders can act as a beacon that can be utilized for localization. An underwater vehicle (e.g. AUV, ROV) will be able to do sequential ranging to find the location of the transponder during a search and rescue operation.

A common problem in mobile robotics deals with answering the question: “Where am I?”. If the robot is equipped with GPS (Global Positioning System) receiver, it can be localized accurately. Unfortunately, GPS doesn’t work underwater. For GPS to work underwater, the GPS receiver should be able to receive the Radio Frequency (RF) signals from GPS satellites. But RF signals do not propagate well in water and therefore GPS receiver cannot receive the signals underwater. Acoustic communication is the most promising mode of communication underwater. With static reference underwater acoustic modems acting as “satellites” in the ocean, we can localize an underwater robot/vehicle.