OPPORTUNITIES AND CHALLENGES OF SATELLITE COMMUNICATIONS IN MARITIME VHF BANDS

摘要

The modernization of maritime communications in VHF has taken momentum by introducing VHF data exchange system (VDES) that replaces traditional analogue voice communication channels with digital data exchange links. In preparation for the Agenda Item 1.16 of the World Radio Conference, held in November 2015 (WRC15), a significant work was carried out to define the specifications of VDES including both the terrestrial and satellite components. As the outcome of WRC-15, the use of VDE terrestrial components as well as the ship-to-satellite use of Application Specific Messages (ASM) was approved. In addition, a revised resolution (known as Resolution 360) was proposed for the World Radio Conference 2019, particularly dedicated to VHF data exchange via satellite (both on the uplink and downlink). The Resolution 360 encourages all administrations to carry out further studies on satellite uplink and downlink and invites administrations to participate in, and support, field trials of the VDES satellite component. In this paper, we review the status and the use of spectrum in VHF maritime band for two-way satellite communication systems. The paper also addresses design directions and trade-offs in VDE satellite definitions and provides a mission concept serving relevant maritime applications.