Automotive Ethernet

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Preface to the Second Edition ix
the executive manager did not expect BMW to be capable of. They invested in and
developed a respective Ethernet PHY product.
However, shortly after, the IEEE released an Ethernet specification for the same use
case. This IEEE version was seen as technologically inferior. However, it had one technical advantage over the proprietary technology the executive manager’s company had
invested in: It was backward compatible to previously designed IEEE Ethernet technologies. The IEEE technology prevailed, whereas the solution they had invested in never
gained any serious traction. In consequence, they would not again invest in a technology
that was not a public standard. The prospect of the OPEN Alliance acting as an organization ensuring transparency with respect to licensing and technical questions did not
make any difference to them.
Today, five years later, in 2016, we know that if that semiconductor company had
invested in 100BASE-T1/BroadR-Reach in 2011, its business prospects today would be
excellent – not only because the technology persevered but also because the company
would have been early in the market. Was the executive all wrong in saying that it needs
to be a public standard? I do not know.
Many things happened in the meantime. Based on experiences with BroadRReach/100BASE-T1, what BMW had wanted to begin with became doable: transmitting
100 Mbps Ethernet over unshielded cables during runtime using 100BASE-TX PHYs.
This solution, sometimes called Fast Ethernet for Automotive (FEFA), was based on
a public IEEE standard. For BMW, it came too late. But most other car manufacturers had not yet made any decisions. For a while, it was not certain whether the “proprietary” (but licensed) BroadR-Reach would succeed in the market or the tweaked
“public” 100BASE-TX.
Well, today we know: BroadR-Reach made it. But, in the meantime, it has also
become a public standard, called IEEE 802.3bw or 100BASE-T1. Only three weeks
after handing in the manuscript of the first edition for this book, a respective Call For
Interest (CFI) successfully passed at IEEE 802.3. The IEEE released a “BroadR-Reach
compliant” specification as an IEEE 802.3 standard in October 2015. Maybe BroadRReach would have succeeded even without IEEE’s blessing. Who knows? The fact is,
the IEEE standardization made life easier. It erased the topic of technology ownership
from discussion.
And it was a main motivator to write this second edition. The now publicly available
100BASE-T1 and BroadR-Reach specifications allowed us to go into detail. The reader
will thus find a significantly extended PHY chapter, which now includes a detailed
explanation of the 100BASE-T1 and 1000BASE-T1 technologies, whose standardization has also been completed in the meantime. While the description of the 100BASET1 technology includes experiences while implementing and using the technology, the
1000BASE-T1 description includes the methodology used behind developing a technology in case of an unknown channel – something new and useful also for future development projects.
Furthermore, the PHY chapter now has a distinct power supply section. Specifications on wake-up and Power over Dataline (PoDL) been released in the meantime, and
are in need of context. Additionally, power supply impacts the EMC behavior. How this

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