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Showing posts from November, 2009

The Future of Sensor Networks

I am occasionally asked by new faculty and grad students (at other schools) whether they should get involved with sensor networks. The concern is that the field has "peaked" and there are risks associated with jumping into an area that may have past its prime. I'm not sure I agree with this assessment. It is true that much of the low-hanging fruit has been picked: after all, the field has been active for about a decade. Rather, I see this as an opportunity to ask where should the field be going in the next ten years. We had a panel on this topic at SenSys 2009, for example. A few thoughts.

First, I think it's important for anyone (new faculty member or grad student) to avoid being too narrow in their research scope. I have always considered myself a "distributed systems person" with a recent fetish for sensor networks, not a "sensor networks person" per se. The set of questions I am interested in find manifestations in sensor networks, but also in …

SenSys 2009, Day Three

Today's the last day of SenSys 2009. Some pictures from the poster and demo session are up on the CITRIS website.

The morning session on time synchronization features one of the award papers -- Low-power clock synchronization using electromagnetic energy radiating from AC power lines. This is a very well-executed paper that leverages specialized hardware to pick up the magnetic field radiating from AC power lines to establish a common 60 Hz clock source for a set of sensor nodes. Nodes measure a common frequency but experience local phase offsets, which are corrected for using message exchanges. The hardware only consumes 58uW so this is a very practical approach. If this hardware were widely available, this could be the last word on time synchronization, at least in settings where nodes are deployed in the vicinity of (not necessarily plugged into!) AC power - including buried and overhead power lines.

Shuo Guo from University of Minnesota gave a talk on FIND: Faulty Node Detection…

SenSys 2009, Day Two

Report from Day Two here at SenSys.

Last night at the organizing committee dinner I had the pleasure of chatting with Kris Pister, founder of Dust Networks and the originator of the term "smart dust". I got to pick his brains on the state of sensor networks in industry and the gap between academic work in the area and real-world demands. Kris had a couple of interesting comments. Dust Networks has made major inroads into wireless sensing for industrial automation and is behind the Wireless HART standard. He noted that academics are generally allergic to leveraging fine-grained time sync to enable TDMA and coordinated channel hopping, which can greatly improve reliability. It's true that most academic work favors a CSMA approach. I think there are two reasons for this: first, we don't happen to have a good TDMA implementation for, say, TinyOS that is easy to integrate with existing code. Second, once you go down the TDMA route it taints many aspects of your system desi…

SenSys 2009, Day One

I'm here in Berkeley for SenSys 2009, the premier venue on sensor network systems. There are 21 papers in the conference this year (out of about 120 submissions) and the quality of the papers is very high. The proceedings have been posted online here. I happen to be the program co-chair along with Jie Liu from MSR, so I feel compelled to blog about the conference.

This morning, Bill Weihl from Google gave the keynote presentation on "The Power of Energy Information." He talked about Google's PowerMeter system which allows consumers to track and visualize the power consumption in their homes -- potentially allowing people to learn about their patterns of electricity use and identify anomalies (like a broken air conditioner). Bill also talked about preliminary work at Google to shift power generation load through smart charging of plug-in electric vehicles, dynamically turning charging on and off across fleets of vehicles based on the grid's fluctuating capacity. It…