A decade ago, AIS was cutting edge technology and today it is still a relatively young system. Class B CS-TDMA was new and unknown to the market, and so a black-box connected to a chartplotter or multi-function display (MFD) via NMEA 0183 was state of the art. It wasn’t until Vesper Marine launched its WatchMate WMX850 in 2010 that an AIS transponder solution became an integrated, standalone system.
When the technology was first launched, getting the data on to a Chartplotter or MFD (if it supported the required NMEA sentences) posed issues early on with interoperability, especially with older chartplotters that didn’t support or understand these new AIS sentences. Another option at the time was a stand-alone receiver-only display, like the WatchMate WM750.
In 2010, there were two AIS options. Class A SO-TDMA designed for large commercial vessels and Class B CS-TDMA, a de-featured but more affordable solution, better suited to smaller commercial or recreational vessels. The AIS protocol has since expanded, and now includes Class B SO-TDMA and accommodates new classes of AIS equipment that use RA-TDMA, and FA-TMDA access schemes like Aids to Navigation Beacons (AtoNs), Man Overboard Beacons (AIS MOBs) and Virtual AIS Stations.
The new Class B SO-TDMA fills a need for fast moving recreational power boats or for use in congested waterways where updated information is needed more quickly to ensure accurate collision avoidance. However, Class B CS-TDMA is still a fine choice on vessels that cruise below 14 knots.
Today, a cutting edge AIS system does more than just send and receive AIS messages. It's tightly integrated with other vessel VHF safety systems, like VHF voice and DSC, and provides its own set of stand-alone intelligent safety features for collision avoidance and MOB situations. It integrates with the rest of the vessel's systems over NMEA 2000, not only distributing the AIS and GPS data it receives to an MFD, but also using the available data to augment its own capabilities, like sending your vessel's heading information with a position report. It also uses wireless technologies like Wi-Fi and cellular to provide remote control and distribute the information it gathers to smartphones, tablets, watches and even the cloud.
The original and primary intent of AIS is focused on vessel to vessel collision avoidance. It complements other systems like VHF, DSC and Radar, as another tool available to the ship's master. It is natural that as these technologies evolve they will become more integrated and easier to use, rather than remaining disparate and spread across multiple devices.
However, AIS has also filled a need for maritime digital data exchange and it is now commonly used to broadcast Aids to Navigation (AtoNs). For example, for weather data, navigational hazards or virtual shipping lanes. The popular benefits and broadening adoption of AtoNs will eventually see the AIS channels become overloaded and that could harm the protocol's effectiveness at delivering the vessel to vessel safety benefits it set out to during its inception.
Current and future advances in maritime digital communications look to provide fast, reliable autonomous communications, while protecting the integrity of the existing AIS network for vessel to vessel safety. The VHF Data Exchange System (VDES) defines new VHF channels for higher bandwidth, free and secure digital communications from vessel to vessel, vessel to shore, or vessel to satellite. AIS will continue to operate within VDES, but the new data protocols open up exciting possibilities for the further enhancement of safety systems and autonomous exchange of data on the water.
The advances in ASIC, FPGA, SoC, open source software and cloud computing have provided the platform for recent marine electronics innovation in general, whether it be MFDs, depth sounders, thermal cameras or AIS Transponders. From an AIS perspective, much of the signal processing required to encode and decode the AIS messages can now be defined in software. This replaces a large portion of the more traditional hardware intensive analogue implementation, which makes it easier to manufacture, faster and offers greater capability.
What does the future of AIS look like? It's inevitable that integration into VHF systems like Vesper Marine’s Cortex are natural progressions. AIS, VHF voice and DSC when tightly integrated into one user experience makes for a very powerful communications system. Further integration with Cortex-like systems and other systems on board (MFDs in particular) is also likely, providing the ability to interact with vessel control systems from more than one place, on board and ashore.
AIS is here to stay and there is no question of its safety value. The next 10 years of AIS evolution and maritime VHF communications innovation will continue to enhance safety at sea, but it will also provide the communications platform needed to support future maritime products and services.