As automation and connectivity drive the automotive industry forward, vehicle networks are evolving. In answer to the growing need for bandwidth, flexibility and cost-effectiveness, Ethernet is emerging as a preferred choice over traditional in-car networks.
Automotive Ethernet has been slowly but surely making its way into cars over the last 10 years, with more OEMs choosing to use it to boost bandwidth in vehicles that are becoming increasingly connected.
So, what is Ethernet and why is it so much better than current networks? How will it affect network architecture and what will the impact be on the automotive industry?
What is Ethernet?
Ethernet should be familiar to all of us. Developed in the 1970’s, it has become the standard for general computer networking around the world. You might find yourself using it to connect your home computer to your router or modem, and if not, you will certainly be aware of Ethernet’s cable-free counterpart, WiFi.
Although Ethernet has not been widely used in the automotive industry until recent years, it is a mature technology with over 30 years of use in the wider networking market. A host of networking protocols and security methodologies have been developed in that time, that lend themselves well to the challenges of automotive networking and cyber security.
Automotive Ethernet has become a hot topic in the industry. Until now it has been used primarily for diagnostics, in-vehicle-infotainment (IVI), and remote sensors. Data heavy, these systems require greater bandwidth to transmit data at the speeds necessary to maintain driver safety. Speeds that networks such as CAN and FlexRay are unable to provide. When you consider the growing interest in autonomous vehicles and the connectivity they will require, you begin to see the benefits Automotive Ethernet has to offer.
Automotive Ethernet has clear benefits.
Autonomous vehicles (AVs) will require a host of connectivity features to function effectively. Cameras, Lidar, Traffic Sign Recognition, are all necessary for automation. These sensors, which enable vehicle to vehicle (V2V) and vehicle to infrastructure (V2I) connectivity (more commonly referred to collectively as vehicle-to-x, or V2X), are vital to their success, and as such the demand for greater bandwidth is set to explode.
Automotive Ethernet, a flavor of regular Ethernet, is optimized for vehicular use. It is designed to offer cars greater bandwidth than their usual networks, offering speeds of up to 100 Mb/s in its current form, and is soon to reach faster speeds with the IEEE802.3 working group, which is responsible for Automotive Ethernet, working on a much faster multi-Gig standard for the future. Contrast this to the Kb/s and low Mb/s speeds offered by CAN and LIN, and you see its appeal.
It has a rival in MOST, a network which has been primarily used for infotainment and media systems. MOST offers 100-150 Mb/s speeds, however proprietary licensing, restricted access to hardware, and reliance on heavy coax cables, or easily damaged optical fiber have limited its market.
Ethernet pulls ahead in its future bandwidth potential, a wealth of potential providers, and with switch networking, offers greater scalability. It also provides a lightweight and cost-effective solution, with Broadcom, the company responsible for introducing the current standard, estimating that they can reduce connectivity costs by 80% and cable weight by 30%.
When you consider these benefits along with its obvious compatibility advantages for connecting vehicles to broader smart-infrastructure, it makes sense that Ethernet would lead the charge in the future of V2X connectivity. But increased compatibility to existing infrastructure and networking methods brings new challenges in cyber security.
Ethernet poses different Cyber Security challenges.
Current cyber security offerings focus on protecting the CAN bus from compromised Electronic Control Units (ECUs), and whilst rogue ECUs will still be the core threat to consider with Ethernet networks, the physical switch network architecture and virtual segmentation it utilizes will inherently mitigate the risk they pose to some extent.
This flexible and modular structure, offers opportunities to tailor specific security solutions, allowing network designers and security consultants to both preserve and leverage the features that make Ethernet so attractive. Furthermore, in the same way that Automotive Ethernet is a flavor of traditional Ethernet, car manufacturers can expect to see automotive adaptations, or flavors, of Ethernet cyber security. To fully take advantage of this cross-pollination from traditional networking, they should look to an automotive security platform to host them.
Automotive Ethernet security strategies will need to include more than just detection and override, or the dropping/redirecting of malicious signals. Compared with CAN techniques, handling rogue messages or ECUs properly and effectively means considering the specifics of the network. Things like its architecture, protocols and applications.
Ethernet and its extensions also deal with network resource management and offer a variety of attack vectors and scenarios, from unused ports, MAC spoofing, and bandwidth abuse, to the more sophisticated, such as TCP hijacking and VLAN hopping among others. Solutions will require effective data management techniques and a more complex network management system. This will require more active methods of protection, as well as in-depth consideration of security requirements at the stage the network architecture is designed.
Network design will require a rethink at all levels.
Although Ethernet will likely replace the other in-car networks in the long-term, CAN, CAN-FD, and LIN will likely remain relevant for the near to mid-term. They are established, cost effective and will remain relevant for certain solutions, especially those where low cost and low bandwidth are key design specifications.
Automotive Ethernet is rapidly reaching adoption targets set by the automotive industry, with diagnostic and infotainment uses either already reached, or just a quick leap away. Driver assistance and network backbone use cases are set to become a functional reality in the near future. Network architecture should be model specific, as both low and high-end vehicles have different need. Cyber security will need to be a fundamental design consideration. It can no longer be an afterthought or tertiary requirement.
Automotive Ethernet is flexible and modular, an effective cyber security solution will complement this and be able to evolve with network design. This would mean that car manufacturers wouldn’t have to rethink their solution with every model. However, in comparison to CAN, Automotive Ethernet cyber security is complex, and will require expertise and dedicated central management.