End of a project

15.11.2015 11:38

Two weeks ago, the CREW project concluded with a public workshop and a closed meeting with reviewers invited by the European Commission. Thus ended five years of work on testbeds for wireless communications by an international team from Belgium, Ireland, Germany, France and Slovenia. I've been working on the project for nearly four of these years as the technical lead for the Jožef Stefan Institute. While I've been involved in several other projects, the work related to CREW and the testbed clusters we built in Slovenia has occupied most of my time at the Institute.

Spectrum Wars demo at the Wireless Community meeting.

Image by Ingrid Moerman

It's been four years of periodical conference calls, plenary and review meetings, joint experiments at the testbeds, giving talks and demonstrations at scientific conferences, writing deliverables for the Commission, internal reports and articles for publication, chasing deadlines and, of course, the actual work: writing software, developing electronics, debugging both, making measurements in the field and analyzing data, climbing up lamp posts and figuring out municipal power grids from outdated wiring plans.

It's funny how when I'm thinking back, writing is the first thing that comes to mind. I estimate I've written about 20 thousand words of documents per year, which does not seem all that much. It's less than the amount of text I publish yearly on this blog. Counting everyone involved, we produced almost 100 peer-reviewed papers related to the project, which does seem a lot. It has also resulted in my first experience working with a book publisher and a best paper award from the Digital Avionics Systems Conference I have hanging above my desk.

Measuring radio interference inside an Airbus cabin mockup.

Image by Christoph Heller

Remote writing collaboration has definitely been something new for me. It is surprising that what works best in the end are Word documents in emails and lots of manual editing and merging. A web-based document management system helped with keeping inboxes within IMAP quotas, but little else. Some of this is certainly due to technical shortcomings in various tools, but the biggest reason I believe is simply the fact that Word plus email is the lowest common denominator that can be expected of a large group of people of varying professions and organizations with various internal IT policies.

Teleconferencing these days is survivable, but barely so. I suspect Alexander Graham Bell got better audio quality than some of the GoToMeetings I attended. Which is where face-to-face meetings come into the picture. I've been on so many trips during these four years that I've finally came to the point where flying became the necessary evil instead of a rare opportunity to be in an airplane. Most of the meetings have been pleasant, if somewhat exhausting 3 day experiences. It is always nice to meet people you're exchanging emails with in person and see how their institutions look like. Highlights for me were definitely experiments and tours of other facilities. The most impressive that come to mind were seeing Imec RF labs and clean rooms in Leuven, the w-iLab.t Zwijnaarde testbed in Ghent and Airbus headquarters near Munich.

Instrumented Roombas at w-iLab.t

(Click to watch Instrumented Roombas at w-iLab.t video)

One of the closing comments at the review was about identifying the main achievement of the project. The most publicly visible results of the work in Slovenia are definitely little boxes with antennas you can see above streets in Logatec and around our campus. I have somewhat mixed feelings about them. On one hand, it's been a big learning experience. Planning and designing a network, and most of all, seeing how electronics fails when you leave it hanging outside all year round. Designing a programming interface that would be simple enough to learn and powerful enough to be useful. If I would do it again, I would certainly do a lot of things differently, software and hardware wise.

Different kinds of sensor nodes mounted on street lights.

While a number of experiments were done on the testbed, practically all required a lot of hands-on support. We are still far from having a fully automated remote testbed as a service that would be useful to academics and industry alike. Another thing that was very much underestimated was the amount of continuous effort needed to maintain such a testbed in operation. It requires much more than one full-time person to keep something as complex as this up and running. The percentage of working nodes in the network was often not something I could be proud of.

For me personally, the biggest take away from the project has been the opportunity to study practical radio technology in depth - something I didn't get to do much during my undergraduate study. I've had the chance to work with fancy (and expensive) equipment I would not have had otherwise. I studied in detail Texas Instruments CC series of integrated transceivers, which resulted in some interesting hacks. I've designed, built and tested three generations of custom VHF/UHF receivers. These were the most ambitious electronic designs I've made so far. Their capabilities compared to other hardware are encouraging and right now it seems I will continue to work on them in the next year, either as part of my post-graduate studies or under other projects.

SNE-ESHTER analog radio front-end.

I have heard it said several times that CREW was one of the best performing European projects in this field. I can't really give a fair comparison since this is the only such project I've been deeply involved so far. I was disappointed when I heard of servers being shutdown and files deleted as the project wound down, but that is how I hear things usually are when focus shifts to other sources of funding. It is one thing to satisfy own curiosity and desire to learn, but seeing your work being genuinely useful is even better. I learned a lot and got some references, but I was expecting the end result as a whole to be something more tangible, something that would be more directly usable outside of the immediate circle involved in the project.

Posted by Tomaž | Categories: Life

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