IEEE 802.15 Positive Train Control Study Group

Many of you may be familiar with the IEEE 802 organization, if in no other way by its standards that have become the mainstay of wireless communications, like IEEE 802.11 (Wi-Fi), 802.16 (WiMAX), 802.15.4 (used by ZigBee, WirelessHART, ISA 100, 6LoWPAN, and others).

Standards development is a challenging matter, since it only comes by bringing together competitors and opposing entities into the same room and working together to create standardized approaches to a variety of problems.

The group that I helped to create, IEEE 802.15 Positive Train Control (PTC) Study Group, is focused on the vital wireless link between the train or locomotive and the infrastructure along the track ahead. While the current concentration is mostly to ensure that a train does not “exceed its limits authority” or exceed its speed restrictions, the future could see the need for a train to talk to bridges, overpasses, or other infrastructure that could impact the safety of a fast-moving train.

Now that we are in Study Group phase, this means that it’s time for us to concentrate on writing our Project Authorization Request (PAR) and our Five Criteria (5C) documents. To make that effort possible, the group will have a Call for Applications, which will allow interested parties to begin to submit technical proposals for how a future wireless standard will be applied in the real world. Fortunately, PTC is a fairly well defined application, but even there, there are nuances that may prove very important to the final standard. As well, this standard must be something that can grow and remain flexible for future applications which we may not even have considered yet.

While what we’re working on is a new standard, in IEEE parlance, the work could result in an amendment to an existing standard (like 802.15.4) or a new number (802.15.10?). That’s why the call for applications is so important – it helps establish the scope of the task.

Some important considerations might include the use of licensed bands, support for narrow-band, possibly non-contiguous radio channels, fairly low data rates, very high speed mobility, and a lot of non-line-of-sight (NLOS) propagation paths. As a train moves along, it may pass from one geographic region to another, and the operating channels may be required to change as the train moves. And it always needs to be kept in mind that this may ultimately be for vital (life and safety) communications, so reliability, robustness and security are important matters as well.

I’ve been working on systems in many ways similar to this for most of my professional career, from deep-space missions (where oops! could mean the end of a multi-billion US$ mission), to very high volume consumer and industrial silicon chip-level wireless systems, and for the past 10 years working to drive standardization of approaches used in the industry to reduce cost, increase the potential for interoperability, and generally to improve reliability and robustness.

If this is your cup of tea, I strongly encourage you to participate in our Study Group. You can get plenty of details here.

The More Things Change, the More They Stay The Same (in Wireless)

Happy (nearly) Ides of November! Earlier this month I tendered my resignation at Freescale, the remnants of the old and formidable Motorola Semiconductor Products Sector. I’m in the process of moving on, and have my sights set on a startup in the wireless communications business. I spent the last week at the IEEE 802 meeting in Atlanta, getting an 802.15 Interest Group converted to a Study Group (100% success, vote was 49 yes/ 0 no/ 0 abstain; and the 802 Executive Committee gave unanimous approval). What’s it all about? Positive Train Control!

Ok, so what’s that and what does it have to do with radio?

If you’re a US resident and ride commuter rail, you might remember the horrific accident back in 2008 in Chatsworth CA where a westbound Metrolink train ran through a red signal and proceeded to collide with a Union Pacific freight train headed eastbound. 25 people died. The Metrolink train engineer/operator was busy texting his friends while his train ran the red light. Currently, there’s no broadly adopted, standardized method to wirelessly link that red signal with the Metrolink train so that running the red light would cause the Metrolink locomotive to stop, or better yet, to prevent the Metrolink locomotive from even being able to run the red light.

So that’s where Positive Train Control comes in. There’s already been a huge amount of work done to date to establish the systems that do the analysis of the real-time data and make decisions on what should happen, but the wireless link that runs from the trackside (wayside) equipment, like that red signal, to the locomotive, is still a mix of proprietary techniques and methods that may or may not be well vetted.

Enter the IEEE 802. This group is pretty famous for solid radio standards, and broad industry adoption of its standards. And it’s a perfect home for the establishment of a Task Group focused on developing the standard for that wireless link from the wayside equipment to the locomotive, and vice-versa. So stay tuned, there’s more exciting stuff to come along over the next few weeks and months as we move from a Study Group toward Task Group and the ultimate goal of creating a wireless standard that will save lives.

Yep, it’s a little different than what I was doing before, but at the same time it’s all wireless, and the need for standards has never been more important than it is for this effort.

Sincerely, Jon