Timely Ship Monitoring Via Satellite: A Perspective on Age of Incorrect Information

The ability to collect via satellite status updates from vessels is a key enabler for a number of maritime applications. In these settings, maintaining an up to date perception of the state of a ship is paramount, yet challenging due to the large number of vessels in the satellite coverage. To tackle the problem, we study the impact of different transmission policies, capturing system performance in terms of age of incorrect information (AoII). Modelling channel contention as slotted ALOHA, we consider a benchmark inspired by the de-facto AIS/VDES transmission standard in which ships periodically report their state, and compare it to solutions that adapt the transmission probability to current ship-to-satellite channel conditions and to relevant changes in the ship state. By means of a Markovian analysis, we derive closed-form expressions for the average AoII, and discuss the performance in settings of representative of practical conditions. The potential of solutions that tie channel access to the evolution of the process to be tracked clearly emerges. The work aims at stimulating further research in this domain, having in mind future enhancements of ship communication standards.