Rise of the Ethernet!
Networking is an expanding part of our automobiles that seems to be rapidly changing. Here is a small introduction into our observations. We have released our latest training manual, Vehicle Network Diagnostic Strategies and currently have many classes going on all over the US.
Here is an article I wrote on the subject which I hope you find interesting and enlightening.
In today’s world you just can’t go fast enough, and in this case, we are not talking about horsepower. Ethernet being introduced into the automotive sector is living proof that our slow networks of today will not prepare us for tomorrow. You may be thinking that we are talking about the future of the automobile, but the reality is, we are already here. As a matter of fact, Ethernet has been in small numbers of production vehicles since 2009. We may get Ethernet and Internet confused but Automotive Ethernet is just a standard of data transfer (IEEE 802.3 and 802.1 to be exact). This technology is nothing new, it has been around for over 30 years. As we all know Autonomous Driver Assisted Vehicles are showing up in all automotive product lines, we do not expect this growth to stop any time soon. The problem with adding all this needed technology into the current automobile is that automotive networks today are just not fast enough to make decisions and that can endanger human lives. BMW is the leader in the technology today, but other manufactures like Hyundai, Audi, Jaguar and Land Rover have already introduce Ethernet in some of their product lines. According to automotive analyst as of 2014 only 1% of vehicles sold were using the Ethernet technology but by 2020 it is expected to be up to 40%. That should make us aware that if you are not seeing this in your shop today that you will be seeing it in the next couple of years.
- Standardization of Bus communication, wiring and connectors in vehicle can reduce production cost up to 80%.
- Transfer High Definition and Panoramic camera data efficiently.
- Ability to stream DVD, Internet and WIFI at extremely high bandwidths.
- Proven technology for over 30 years, also used in many other applications
- Sustainability - since it is an TCP/IP address protocol, easy to adapt and expand systems with plug and play hardware.
- Faster Programming and uploading data into the vehicle (up to 100Mbps or 2 x 100 Mbps) this is 10 to 20 times faster than FlexRay.
- Ethernet is susceptible to electro-magnetic and radio frequency interference. One of the largest concerns for installing Ethernet in Automobiles. - Potential for cyber security risk from hackers or malicious virus. - Problems with dedicated bandwidth when using multiple network structures.
Network and Domains
The automotive networks up until now have been designed with multiple protocols. That creates many different wiring connectors and gateway modules to bridge the gap between the domains. Here is a list of normal domains in current automobiles.
- Powertrain (Engine Management and Transmission Control)
- Body and Comfort (Climate Control, Instrument Panel and Power Accessories)
- Chassis (ABS, Traction Control, Electric Power Steering and Adaptive Suspension
- ADAS (Advanced Driver Assisted Systems – (Lane Keep, Driving Assistant, etc.)
- Human machine interface (Bluetooth, Voice Command, DVD, Navigation and Multi Screen Interfaces)
Below is a list of domains and their current bandwidth and latency requirements. Keep in mind that these are the requirements that are used today and give us an idea of what the requirements of speeds are going to be in the future.
As you can see from the chart above that the Driver Assistance domain requires much more bandwidth compared to the other networks in the vehicle.
Ethernet looks promising to remove all the separate complicated networks in our vehicles, streamline one complete network wit⁄h TCP/IP addresses and even PoDL (Power Over Data Lines). This will vastly reduce wiring harness sizes which will reduce cost and complexity.
Variations and Protocols
There are variations of Ethernet used in many different areas of electronics today. In the Automotive industry these are current standards used.
100Base-T protocol (IEEE 802.1)
This was introduced in 2009 to increase programming upload speeds into vehicles. Directly connected through the DLC (through a 4 or 5-wire connection) to allow faster uploading of data packets into the vehicle. The change in data transfer from CAN, at 8 bytes was increased to over 1500 bytes per message. This was a major leap forward in data transfer, from Programming Device to car. Having a frequency of 62.5 MHz, manufactures were concerned that could cause EMI/RFI interference. Concerns of this new technology being installed in a production vehicle for the first time, the system was completely disabled when the diagnostic device was disconnected from DLC.
OABR, (OPEN Alliance BroadR-Reach) (IEEE 802.3bw) 100BASE- T1
One Pair Ethernet is the newest version introduced in 2015. This application uses an unshielded twisted pair of wires created to interface the multiple camera systems transferring high speed data. Bringing the ability to carry extremely fast data across the network using only one pair of wires. Keeping the cable length to less that 15 meters allowed increasing the speed over one pair of wires. Lowering the frequency of the data transmission to 33.3MHz allowed manufactures to significantly reduce the chance of inference and noise. This new technology has speeds up to 100Mbps on each wire in a bidirectional format. That means the total of speed for the protocol is 200Mbps combined. Growing quickly in the BMW platform since 2016, OPEN protocol has completely take over the camera and driver assistant network.
Example of 2018 BMW X3 (G01) ethernet topology.
RTPGE (IEEE 802.3bp) 1000 Base-T1 (Reduced Twisted Pair Gigabit Ethernet)
Although still in its experimental phase, 1000 Base-T1 Ethernet looks to be the next evolution in Automotive Networks. With speeds up to 1000 Mbps this could completely change the way we look at networking in our vehicles. This technology has already pass its first test and is ramping up to start being introduced into our automobiles in the next couple of years.
Testing and Equipment
Giving the changing technology in our Automobiles today. The way we are testing extremely high-speed networks is changing just as fast. Currently the automotive Oscilloscopes we are using in our shops today may not be capable of capturing data from the Ethernet network. There is equipment out there capable of this, but you will need a 1Ghz Oscilloscope with at least a 2GS/s sample rate and 10GS/s sample rate is recommended. Also, when testing Ethernet, it is not like a CAN network Topology where the signal is available over the entire network. With Ethernet you will only have the information sent to the location it is need at a specific time and not everywhere across the network. This can cause issues during testing because you may have trouble duplicating the fault on the exact part of the network where the problem exists. With this being said, it may be more suitable to use Scan Tool data and test plans to isolate the problems. As more of the problems with Ethernet arise better plans for testing strategy will be put in place.
ATG TIP: From our research and initial testing the cabling between the Ethernet networks should have impedance of 100 ohms plus or minus 10%. The built-in resistance is extremely important to the stability of the signal transmission across the wires. This should be a measurable specification on most car lines. Although it is too early to be very specific, most manufactures do not give very reliable test plans for Ethernet problems currently.
With all the advancements going on in our Automobiles today it seems that all technologies are merging together. Our consumers are demanding a more connected world. Ethernet is playing a role in this from our computers at home and now merging into our Automobiles. This partnership is looking inevitable and we should start to prepare ourselves for this evolution in the cars of the near future.
Hey how u doing sir. I've recently have bought alot of ATG books and I can't tell u how much I learned from them. I keep reading them over and over. I called about the vehicle network Diagnostics but it wont be coming out for a couple of months. I live in Jersey and I dont see any class anytime soon u guys are coming down here. Is there a way I can buy it before hand. Plus I am about to order