Sunday, December 12, 2010

Globecom, WSN forum, Urban-scale sensing talk by Ed Knightly (Rice U)

Last week, I attended Globecom'10.

Ed Knightly from Rice talked about urban-scale sensing under 3 parts: vehicular sensing, health sensing, and smart grid.

Ed spent most of his talk on the vehicular sensing part. A recent US deparment of transportation vehicle safety commission project asked this question: vehicles have dozens of sensors already, what if this information was shared, what can we achieve? Some low hanging fruits are: traffic signal warning, curve speed warning, left turn assistant, stop sign movement assistant, lane change warning, collision warning, and finally, internet access applications.

The candidate technology that is proposed for making this networking feasible is a wireless technology, of course. But not the wifi technology which is probably many people's first guess; It is visible light communication (VLC) technology. A VLC transmitter is a LED, which can as well be the LED headlight and taillight in most of the recent models. The only thing needed is to modulate the signals at high frequencies at these LED sources in the visible light spectrum. (VLC is invisible to the naked eye, because it is just modulated too frequently to register at our brains.) VLC receiver is a photodiode, which can again be installed next to the lights in the front, back, and the sides.

More good things going for VLC (aka free space optical communication) are as follows. VLC is green. You get good bandwidth with little energy expenditure. VLC is directional, good for vehicular applications. Sun interference is not a problem, unless there is a direct sunset interference, ambient sun or shadow environment does not interfere with VLC. 400Mbits/sec is the current physical level record for VLC. Ed noted that Boing is trying to push this VLC technology in planes, as it is untintrusive to other equipments on the plane.

The second topic Ed talked about is the health applications of sensing.
Ed said there is an app for a lot of health issues, but these apps are not making much use of sensors. (The exception is nike+ipod, which uses a pedometer.) If we can combine those apps with sensing and close the loop, we can diagnose a lot of problems early on. These regular monitorings can enable preemptive medicine and cut down ER costs.

Ed gave the example of the bluebox. Cardiovascular diseases are responsible for 40% of deaths. Bluebox is a $10 device, which is basically a crappy ekg. It is noisy, but using it regularly catches cardiovascular problems a lot before they become dangerous. So, crappy it is, its regular use saves lives. Can we make this sensor available on your smartphone? Another example is the laser breathalyzer for diabetes which helps determine if an asthma attack is imminent. Using this sensor, asthma attacks can be detected much before they occur.

Ed's final topic was smart grid. Smart electrical-grid consists of network-controlled power terminals, as well as thousands of solar panels attached to the grid. There is recent interest in this domain due to green energy sources. Recently, like the Google-meter several sensing solutions are emerging to provide fine-grain (device-level, minute-granularity) accounting of power usage at living spaces. The goal of the smart grid is to be robust, self-healing against attacks and natural disasters.

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