Moving Away from the Wired CultureJuly 20, 2006 By: Tom Kevan
Popular culture has placed its trust in wireless technology, but not everyone is on the bandwagon. Surprisingly, many engineers fall into the second category.
A Culture in Transition
Few people think twice about going into a cyber café and wirelessly connecting to the Internet. On the roads, you can see numerous drivers with cell phones glued to their heads. And if you have kids, you are familiar with the wireless controllers used with Xboxes and Playstations. These are just a few examples of how our culture has embraced wireless communications and placed its trust in this particular element of the wave of the future.
Despite the benefits and advantages of implementing wireless sensor networks, many engineers are still waiting to try wireless technology in their designs and systems. Some implement it only when there is no alternative.
A Case in Point
Sensors' August wireless supplement will include a case study titled "Wireless Sensors Open the Door to Energy Management." In this application, a convenience store is outfitted with an energy management system that controls and monitors built-in and stand-alone coolers, the HVAC system, lighting, and a front-door monitor.
Of all these systems, only the door monitor uses a wireless sensor. The system integrators chose to use the sensor in this application because the metal and glass structure that encloses the door made it difficult to run the necessary wires in a visually appealing way. In short, wireless was the technology of last resort. Before the sensor was deployed, the open question for the system integrators was: Will the radio work? In all fairness, there were a lot of good reasons to wonder if the technology would work in that particular environment. For one thing, the store was chock full of equipment that generated "noise" that potentially could interfere with the door sensor's radio signals. And all the metal cans and containers of fluid on the store shelves weren't exactly wireless friendly. But in the end, the wireless sensor came through with flying colors.
If wireless simplifies installation and reduces deployment costs—and it works—why wasn't the technology used when it came time to monitor temperature and humidity for the other systems in the store?
I believe there are a lot of answers to this question. We haven't yet seen—or at least heard of—many large-scale wireless sensor deployments, so there are no high-profile examples to follow. (Although smaller scale implementations are solid: For instance, see "Shipboard Machine Monitoring for Predictive Maintenance.") Then there's the uncertainty that the technology will work reliably; and invariably, someone in the crowd will be concerned by the fact that no standard is yet widely adopted. Sum it all up, though, and the broad answer to the question is: Our culture hasn't completed the transformation yet. For now, it is: Wireless laptops—yes. Wireless sensors—maybe . . . later.
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