WSN Update

Researchers have long been promising that wireless sensor networks will bring a new wave of smart appliances that can communicate with each other, and with central servers when they need attention. The technology for these appliances has existed for some time now. However, the commercial availability of such products has been slow to market for one primary reason - the lack of structured business model.

All that is about to change now thanks to Verizon Wireless's Open Development initiative. The mobile phone network provider has created a new business model for themselves by opening up their network to allow third party devices to be "certified" (they promise quickly and easily, but who knows what that means) for use on the Verizon Wireless Network. With access to the the mobile network, it will now be possible for devices other than your cell phone to communicate. For example, your HVAC can call you when its about to fail or your fridge can call you when you are running low on milk. These examples might not be the most realistic, but the potential for general machine-to-machine (M2M) applications just got a lot more exciting.

Verizon announced certification of the first device under the Open Development initiative this month. Surprisingly, it is a device that has a sensor that dips into a large container (holding the likes food shortening, etc. ) and automatically sends a text message when the contents are low. I guess the examples above were realistic after all.

Beet.tv has a nice interview with Verizon's VP of Open Development, Anthony Lewis.

Labels: low power wireless, m2m, predictive maintenance, verizon wireless

The Baltimore Examiner reported over the weekend that Washington DC is planning to expand its network of wireless gunshot sensors to cover more high crime neighborhoods in the city. By September of this year, police expect 16 of the city's 68 square miles to be covered by the ShotSpotter technology that pinpoints the exact locations of gunshots.

Once the network is deployed, DC will have one of the largest wireless gunshot networks in the country. According to the Washington Post, the technology has guided police to three homicides in Southeast Washington, and in one case officers got there rapidly enough to make an arrest.

Interestingly, the ShotSpotter website states that US Department of Defense has requested that they limit discussion on the how the gunshot detection technology works.

I don't know why they bother as this is no big secret. The basic idea is simple: using the arrival times of the acoustic events at different sensor locations, the shooter position can be accurately calculated using the speed of sound and the location of the sensors. Vanderbilt University was successful in using this technique to pinpoint a gunshot to an area less than 1 meter, which is supposedly more accurate than the ShotSpotter products.

Regardless of it accuracy, the ShotSpotter is an excellent example of a company that is USING the technology to solve a SPECIFIC problem. As we have mentioned here in the past, it will take a lot more APPLICATIONS of the technology before the market really takes of. It is great to see that ball starting to roll.

Labels: gunshot detection, low power wireless, wireless

Embedded.com has a good article today that is Part III in their series of choosing the right low power wireless sensor network. This article shifts away to the general criteria discussion of parts 1 and 2, and dives into the technical details by comparing TI's proprietary SimpliciTI wireless network with Zigbee.

In a nut shell, the article shows how the need for standardized reliability and security implementation as well as an interoperability requirement would make Zigbee the protocol of choice. Relax or remove these requirements and the optimum network would be a general or proprietary 802.15.4 network.

Full Article...

Labels: low power wireless, pan, protocol, wireless, Zigbee