Mechanical personnel
The birth of terrorism has led to an increase in the use of explosives against U.S. civilian populations, the most recent of which was the attempt to bring down Northwest Airlines Flight 253 on Christmas Day. As a result of such threats, government agencies have invested in robots that gather critical, situational-awareness intelligence and reduce the instances of first responders physically assessing a situation. They hope wireless will help, but reliability is still an issue.
For a scientific perspective on the use of robots, I called Kate Remley, an engineering Ph.D. who currently works at the National Institute of Standards and Technology on public-safety radio systems. She’s been studying robotics for years and has seen them adopted most by first responders who work on bomb-disposal. It makes sense, she said, because commanders and chiefs for years have pushed government officials to support technology capable of providing remote intelligence, versus sending a first responder into a life-threatening situation.
Currently, most robots are powered and controlled via a tether. But Remley said she’s found that responders would like to use robots wirelessly. Yet wireless systems aren’t the most reliable when it comes to robots. A tether can control the robot and send communications without interruptions — but it limits the distance the robot can travel. In contrast, a wireless-controlled robot can get to more places, but it will experience a reduction in signal strength once it moves inside a building, meaning communications may not make it outside to the incident commander, she said.
“That’s a serious issue, especially in cases where we want to send a robot into a tunnel, which is below the earth, so there is a lot of signal reduction … or, in the case of a building collapse, where there is a lot of building material that can reduce the signal level,” Remley said.
Another challenge occurs when wireless devices transmitting on the same frequency interfere with a signal transmitted by a first-responder robot. For example, many robots use unlicensed frequency bands — and so do consumer applications, such as a home wireless network. “So there is an issue with a consumer device entangling an emergency-response scenario, essentially shutting the robot down,” Remley said.
Signal-strength reductions and interference could lead to dangerous consequences, especially in a bomb-removal scenario. As a result, Remley strongly suggested that robot manufacturers not use unlicensed frequencies.
Once interference and signal strength are addressed, there still are two hot-button issues with which to contend: bandwidth and spectrum. Both are needed to support the transmission of data from the robot to incident command. It’s an issue being sorted out by the FCC and public-safety associations, but Remley said both are essential if wireless is to become reliable for the operation of first-responder robots.
“First responders would like to transmit not only the control of the robot — which is a very small amount of data — but also video, which is quite data heavy,” she said. “So there is an issue with bandwidth because robots need a significant amount of spectrum to transmit the video signal.”
For new technologies to work, everyone must be onboard — manufacturers, standards boards, federal agencies and users. But right now, wireless isn’t the best answer because it fails to meet a crucial standard: reliability. Without that, it’s useless.
Listen to a podcast interview with Kate Remley.
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Mary Rose Roberts is the associate editor for Urgent Communications.
