VDES performance evaluation for future e-navigation services

E-navigation is the main IMO initiative to increase safety of navigation in commercial shipping through a better organization of data on ships and on shore, reliable data exchange and the definition of new communi- cation channels between either ships to ship or ship to shore. New technological advancements start from the consolidation of Automatic Identification System (AIS), which is mandatory for some class of ships for the notification of position to other ships, or to the shore, and to send distress signals. In fact, in some high ship- density the allocation of new frequency was declared necessary. In pair with AIS baseline services, additional services are gaining momentum and are available in state of the art equipment, including the handling of send- ing and receiving Application-Specific Messages (ASMs). In this direction, the VHF Data Exchange System (VDES) standard was recently introduced, to improve both on messaging capabilities, system flexibility (stan- dardizing the use of satellite channels) and allowing higher bitrates for application messages. In this paper, we reviewed main characteristics and enabled services of VDES, then we carried out a technical analysis of the new communication standard in terms of channel compositions, supported rates, access schemes and latency. Finally, we designed two possible future VDES applications in order to provide a preliminary assessment of the enabled performance, through a MATLAB model of VDES communications.