Physical layer design towards VHF Data Exchange (VDE) Link

摘要

Towards the overall concept of e-navigation by the International Maritime Organization (IMO), one key element is a new communication system, namely VHF Date Exchange System (VDES). VDES consists of the already existing Automatic Identification System (AIS), Application-Specific Messaging (ASM) and the new to be developed VHF Data Exchange (VDE) link. Currently, an international standard is being developed by the International Association of Marine Aids to Navigation and Lighthouse Authorities (IALA) and the International Telecommunication Union (ITU). The maritime community recognizes the concept of VDES as an answer to the following problems: During the last decade the usage of AIS increased and the AIS capacities are highly stressed. Furthermore, new applications are planned to be introduced to the maritime world such as Maritime Safety Information (MSI) services, vessel shore reporting, real-time hydrographic and environmental information services and ice navigation services. These services also increase the appetite for bandwidth. Currently, the definition of Global Maritime Distress and Safety System (GMDSS) is more than 25 years old and is under way of being revised including new emerging needs. Additionally, communication capacities are not globally available. The Polar Regions are cut off from geostationary satellite data pipelines. There is only a minor terrestrial and satellite communications infrastructure existing, which is contrary to increasing activities (mining, cargo, tourism) due to climate change in these challenging areas. The VDE link is part of VDES. This link contains a terrestrial component (VDE-TER) and a satellite component (VDE-SAT). Therefore, VDE will have a global coverage including bidirectional communication capabilities. Within this paper, current results towards the design of the physical layer for VDE-TER and VDE-SAT will be investigated.