The new standard has been developed by a group of marine electronics manufacturers who asked the NMEA to standardise a method of transmitting and receiving NMEA 2000 messages on Ethernet.
NMEA notes that, while some manufacturers already currently use higher bandwidth Ethernet for video as well as for proprietary messaging on Ethernet to add NMEA 2000 messages, this approach crates problems due to the abundance of different individual solutions.
OneNet aims to transport NMEA 2000 network messages on Ethernet in a standardised manner, establishing standardised gateway rules and supporting high-bandwidth applications such as video data transport, which is not possible using the NMEA 2000 network.
OneNet should provide greater bandwidth, with up to 1 gigabit or faster transfer speed directly to the OneNet devices (400 times the speed of the NMEA 2000 CAN bus) and greater scalability, as OneNet backbones may exceed 100 Mbps using other standard Ethernet physical layers such as Gigabit Ethernet and fibre optics.
OneNet can support up to 65,024 physical devices, versus CAN bus’s 50 devices, allowing the creation of larger and more complex networks, with Power Over Ethernet (PoE) allowing each physical device to be separately powered by up to 15.4 watts directly from the Ethernet switch.
A standard device web page will be produced to provide basic fundamental product information, and a Simple Service Discovery Protocol (SSDP) will be integrated to allow OneNet devices to advertise their presence to other SSDP-compatible devices on the network – in the same way that a printer can tell a PC or Mac that it’s there.
“NMEA OneNet does not replace NMEA 2000,” said NMEA technical director, Steve Spitzer.
“NMEA OneNet uses the physical and network layer standard based on the IEEE 802.3 Ethernet Standard. OneNet complements the NMEA 2000 standard and preserves existing and future NMEA 2000 messages (PGNs).”
“OneNet is not recommended for real-time critical data, because the NMEA 2000 Controller Area Network (CAN) enables prioritisation and guarantees that the message transmitted will always get through to certified devices. IEEE 802.3 cannot provide the same guarantee of message delivery.”
Participating on NMEA’s OneNet Committee are Actisense, Airmar, Digital Yacht, the Electronics and Telecommunications Research Institute of South Korea, FLIR, Fugawi, Furuno, Garmin, Johnson Outdoors, Korean Maritime University, Krill Systems, Maretron, Molex, Mystic Valley Communications, Navico, Raymarine, the US Coast Guard, and Victron Energy.
Additionally, the US Coast Guard R&D Centre has contributed to ensure that OneNet meets the needs of commercial vessels in addition to those of national and international standards authorities.