Cellular VHF Data Exchange System

The VHF data exchange system is a communication system that comprises four different communication systems which having a terrestrial and satellite component. The first one is the established automatic identification system (AIS) that exists all over the world and is mandatory for all vessels that excess 300 gross tons on international voyages. Further, regional requirements make it mandatory for many much smaller vessels and also on national and even inland waters. Therefore, the market size is about 260, 000 vessels worldwide. The market expectation is that all these vessels exchange their AIS into a VDES transceiver in the future. VDES introduces next to AIS a new communication technology that allows to transmit any data by broadcast or unicast connections which is called VDE. VDE is a cellular communication system, but with rather limited capabilities due to the lack of frequency spectrum. Only a 100 kHz in the up- and in the downlink are currently allocated. Further, the spectral co-location of the existing AIS, that is mandatory as a safety requirement, impacts the potential of VDE. This paper investigates different concepts that could be applied in future revisions of the VDE standard. Further we address that the prevailing co-existence with AIS and the mandate of receiving all AIS messages on shore is a significant burden for the VDE roll-out phase and the future expansion of VDE.