20 years after NMEA 2000 and more than 40 years after NMEA0183, OneNet® is the third-generation NMEA standard for interfacing and networking marine data.
In development since 2010 by NMEA members (1), to be published in late 2021, the OneNet standard is based on the IP Internet Protocol (2) version 6 (IPv6) and runs on IEEE Ethernet LAN 802.3. This new standard is intended to combine the three NMEA data standards — OneNet, NMEA 2000, NMEA0183 — on a single local area network (LAN).
The concept
From the outset, NMEA OneNet was designed to complement and extend the capabilities of the NMEA 2000, not to replace it, adding its benefits to an existing NMEA 2000 network. All OneNet Application Protocols, such as PGN messages (4), are intended to use the standard IPv6 network protocol. This allows OneNet to coexist with other protocols and services that run in parallel on the same network, including other marine standards such as IEC 61162-450 (3). The standard also specifies the mechanisms for connecting OneNet networks, NMEA networks 2000 and other networks through dedicated gateways. As for NMEA 2000, all OneNet products will need to be certified by the manufacturer and verified by the NMEA.
The Benefits of Architecture
- With a range of transfer speeds by 10 Mbps to 10 Gbps Ethernet is approximately 400 at 40.000 times faster than NMEA 2000. In this way, OneNet can support high-bandwidth applications such as data transport Radar, Video and Sonar.
- Allowing a much larger number of potential devices (Addresses), OneNet makes it possible to create larger and more complex networks than with the limitation to 252 addresses with NMEA 2000.
- Thanks to Power over Ethernet (Poe), each OneNet device can be powered separately up to 25,5 watts directly from the Ethernet switch, which brings greater power supply.
- Ethernet is a ubiquitous technology used everywhere, in private homes as well as in industrial environments, and therefore appropriate. Many marine electronics manufacturers are already using Ethernet networks, like Furuno.
- In addition, OneNet has no limit on the number of PGNs (4). While NMEA 2000 is limited up to 411 standard PGNs and up to 512 proprietary PGNs, OneNet does not have a significant PGN limit.
Compatibility
NMEA OneNet is designed to work seamlessly with NMEA 2000 (Data messages being identical) and with NMEA 0183 through a gateway (Data messages that require conversion). The NMEA network interconnect diagram below shows how the different gateways connect : OneNet gateway to NMEA 0183, OneNet gateway to NMEA 2000, NMEA 2000 gateway converter to NMEA 0183. Gateways significantly reduce network upgrade costs by eliminating the need to replace existing devices.
➀ Ethernet Hub ② OneNet gateway to NMEA 2000 ③ NMEA 2000 Wi-Fi gateway ④ NMEA 0183 gateway converter to NMEA 2000
The diagram above shows only the architecture of the system. The gateways shown are illustrative only. They should be OneNet certified to truly integrate into the network.
Security
NMEA OneNet has made security a priority from the very beginning of its development. It uses a security model in which the user creates a network OneNet Secure Network and then adds OneNet applications to that network using a process called "pairing" to create a robust secure data network.
Every OneNet application (running on a physical device) must successfully pass the NMEA certification tool tests in order to obtain a certificate that can be used in a secure OneNet network. If the physical device, such as a tablet or mobile phone, is not NMEA OneNet certified, the OneNet application running on it must be NMEA certified in order to join a secure OneNet network and access the data it contains. However, the OneNet network can possibly be left in an open state (Insecure) to allow the use of non-certified devices if the user wishes.
Summary
In the future, this new standard will certainly only apply to "luxury yachting", i.e. large units with many instruments, sensors and peripherals of all kinds : Tall Offshore Racing Yachts, Charter Units, Luxury Yachts. The standard NMEA 2000 has put 15 years to be adopted on pleasure craft less than 20 meters high, starting with the largest and now working on the smallest units, from 25 up to 50 feet. It will be many more years to see the OneNet standard become widespread.
I have, for my own, a question about the use of Ethernet network : it's about the wiring. While Ethernet cables have become very cheap, thanks to a huge manufacturing volume for decades, with regard to NMEA 2000 cables particularly expensive, they have a weak point. Even in a shielded version, which gives them excellent robustness, the common RJ45 connectors are unfortunately very exposed to corrosion in the marine environment. I don't see how we can ensure the perfect waterproofing of it like the NMEA 2000 connector provides. To date, I couldn't find any information from the NMEA on what I think is the "weak link" in the system.
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(1)See Glossary
(2) Internet Protocol : Universal Internet Communication Protocol
(3) AFNOR International Standard
(4) PGN : Parameter Group Numbers NMEA-specific messages 2000
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Related Articles :
Wiring NMEA 0183, not so easy !
NMEA 2000, a network standard for the future
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In most industrial applications in aggressive environments, so-called M12 network connectors are used to replace the RJ45.
Obviously, This can be a hindrance to development, because it's more expensive than the RJ45, and standard equipment with RJ45 jacks is not compatible unless an adapter is required..
There are indeed shielded Ethernet cables Category 5 (1Gb/s) IEC standard 60332-1, equipped with M12-5-pin cylindrical screw-locking connectors, IP67 rating waterproof up to 1 meters. This would require OneNet-approved devices to be equipped with this type of connector, with a price unfortunately equivalent to – or even higher – than the NMEA connector 2000.
Hello,
I confirm for the connectors. In a humid environment, the distribution of drinking water is a problem. So at sea….