gainspan.JPGTucked unobtrusively away in corners and out-of-the-way places, sensors record the world around us — tracking air quality, electricity usage, temperature and other variables. The modern world needs such measurements, but installing and maintaining the sensors is costly.

GainSpan is a Sunnyvale, Calif. company that says it can help cut costs by using wireless sensors that tie into the same 802.11 WiFi radio bands that ordinary computers use, which reduces the number and complexity of the sensors needed. Also, having cheaper, more easily deployed sensors could help raise efficiency through more intelligent monitoring.

For example, if sensors are placed throughout a large industrial building they can monitor temperature more effectively, allowing selective use of heating and cooling systems.

Wireless sensors have been around for over a decade, but they’ve used costly non-standard wireless communication protocols for reasons of battery life. GainSpan says it has tackled the battery problem, extending the life of its WiFi sensors to a standard five to ten years.

If GainSpan can sell businesses and governments on using its sensors, they can be used both for the above scenario and dozens of other purposes, like tracking the movements of miners underground or monitoring the structural integrity of bridges.

There are, however, some challenges to GainSpan’s plan, including signal interference from too many devices. For more on the technical ins and outs, take a look at this paper by University of Virginia researchers. There are also competitors, including Ember and SquidBee, making WiFi sensors using the open-source ZigBee standard.

Opus Capital led the $20 million second round, while existing investors Intel Capital, New Venture Partners, OVP Venture Partners and Sigma Partners also participated. GainSpan’s total funding, with its $10.5 million first round, now stands at $30.5 million.