50 Gbps Ethernet is on the Way

24 Nov 2015 • 2 minute read

Here is my report from the most recent IEEE 802.3 standards meeting, which was held in Dallas during the week of November 9.

The big news is that work on 50G Ethernet is now about to start. The 25G 802.3by project will soon be ending and plans are afoot for the team working on 802.3by to start thinking about 50G Ethernet.

The 802.3bs 400G project has adopted technology for 50G per lane operation. So it follows that 50G single-lane Ethernet PHYs should be created using this technology.

The first stage in creating an 802.3 standard is a call for interest (CFI) at an IEEE 802 plenary meeting. This was done at the recent meeting in Dallas with substantial interest being shown. When the consensus building presentation was made on the Tuesday night, over 100 people indicated that they would work on a 50G project.

As a result, two study groups have been approved to develop suitable objectives for 50G per lane Ethernet:

50Gbps Ethernet Over a Single Lane Study Group
Next-generation 100Gbps and 200Gbps Ethernet Study Group

The first study group is expected to lead to a new project (task force) to develop 50G single-lane PHYs, while the second is likely to amend the 802.3bs 400G project’s objectives to include 100G and 200G PHYs based on 50G per lane technology. It makes sense to do this work in the 802.3bs task force because that project is already focused on developing PCS and PMA solutions for multi-lane PHYs. Also, adding 100G and 200G PHYs to 802.3bs will make it more relevant as the initial 400G market is expected to be small.

The single-lane 50Gbps consensus building presentation can be found here.

Once a study group completes its work, a task force is formed to write the standard. The draft standard goes through three cycles of review:

The early draft (usually numbered as draft 0.x or 1.x) is reviewed and “commented” on by the task force that produces it
The technically complete draft (usually numbered as draft 2.x) is voted (“balloted”) and commented on by the wider 802.3 “working group”
Once approved by the 802.3 working group the draft (usually numbered as draft 3.x) is then balloted and commented on by the even wider 802 “sponsor group”

In addition I should report that progress is being made in automotive Ethernet, where there are five relevant projects:

802.3bw to standardize the 100BASE-T1 (100Mbps) automotive PHY is now complete. The IEEE-SA Standards Board Standards Review Committee gave final approval to IEEE Std 802.3bw-2015 on October 26.
802.3bp to standardize the 1000BASE-T1 (gigabit) automotive PHY is making good progress. The standard is technically complete and will soon go to sponsor group ballot.
802.3bu 1-Pair Power over Data Lines (PoDL), is now technically complete and has started working group ballot. Dave Dwelley, the task force chair, likes to refer to this as the “poodle” project. He gave a pun-laden tutorial on this project, which can be viewed here.
802.3bv to create a standard for gigabit Ethernet over Plastic Optical Fibre (POF). This project is making slower progress and is still in the task force review stage.
802.3br for frame pre-emption. This is useful for sending control frames at defined time intervals. The standard for this is technically complete and will soon go to sponsor group ballot. Cadence is actively participating in the 802.3br project.

Arthur Marris

November 2015