OT: Wayward signals disrupt wireless world

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Wayward signals disrupt wireless world

Monday, February 14, 2000

By JON VAN Knight Ridder Newspapers

A giant construction crane that moves unbidden, a nuclear power unit that shuts down for no apparent reason, and distress signals from a phantom boat are workaday stuff to Brian Mattson and his colleagues.

But the Wheeling, Ill., firm that Mattson manages isn't a local branch of Ghostbusters, though it often focuses on the spookier side of technology.

Errant radio signals, not forces from the spirit world, are what sometimes make electronic control equipment seem to develop a mind of its own. And as wireless phones, pagers, and other gadgets proliferate, the problem grows more complex each year.

It took only a walkie-talkie transmission to trigger a safety mechanism that shut down a nuclear power plant unit, for example. And the Coast Guard once launched a search-and-rescue mission when radio emissions from a computer screen were interpreted as a boater's SOS.

In coming months, amid the introduction of new technology that enables electronic communication without wires, the potential for trouble can only expand.

The problem stems from the fact that transistors -- the basic workhorses of electronics -- can act as tiny radios, sending and receiving weak signals. As more transistors are packed together on computer chips, they are designed to run at lower voltages and higher speeds. That reduces heat emissions and boosts performance, but it also makes them more susceptible to errant radio signals that can cause malfunctions.

Even as the potential for trouble increases, universities are putting less emphasis on electromagnetic interference than they once did, so young electrical engineers tend to have little or no understanding of how vulnerable modern equipment can be.

It all adds up to more work for DLS Electronic Systems Inc., a Wheeling-based specialist in electromagnetic trouble-shooting.

Yet the work isn't always welcome, Mattson said.

"A lot of times, customers will come to us after they'd designed and built a new product and then find there's a problem," Mattson said. "Going back into the process to eliminate the problem can be costly and time-consuming.

"It's often the case where if they'd only thought about this when they first designed their product, it would have been relatively easy to avoid the problem in the first place."

To address the problem, DLS and the University of Wisconsin cooperate to regularly offer engineering courses on electromagnetic compatibility design.

Despite this outreach, the firm's lab equipment regularly uncovers devices that either generate errant radio frequency interference or are themselves susceptible to such interference.

One example is a portable electric power source intended for use in recreational vehicles. The product emitted electromagnetic signals strong enough to interfere with radio and TV reception, which are among the more popular appliances in modern campers.

"They had to recall a lot of products and do a redesign," Mattson said.

Electromagnetic interference is, of course, a phenomenon of modern technology's escalating complexities. It was first noticed by the military in the late 1940s when the strong signals emitted by radar apparatus caused radio equipment to malfunction.

It wasn't until the 1980s that the Federal Communications Commission adopted regulations to address the problems.

"Cordless phones and garage door openers were two of the first items where people started to see interference," Mattson said.

Even though the FCC and regulatory bodies in the European Union have numerous regulations governing appliances and the type of signals they may emit, private companies do the bulk of work to control such emissions.

Often such standards amount to "gentlemen's agreements" subscribed to by industry because it's in everybody's interest that their equipment won't malfunction, said Siemens Corp. engineer Stephen Berger, chairman of one standards committee and a member of another.

There are about 5,000 engineers worldwide who belong to the Electromagnetic Compatibility Society of the Institute of Electrical and Electronic Engineers, the leading international professional organization in this realm.

"Sometimes we develop a standard because there's a noticeable problem," said Berger, "but we prefer to get to work before things get to that point."

There are probably 30 projects going right now in which engineers are developing standards intended to prevent future trouble, he said.

Four different standards to govern wireless local area computer networks are currently competing for favor, for instance.

Providing compatibility between wireless phones and hearing aids so that people with hearing disabilities will be able to use cell phones is another example of this work.

"We're funding five studies to support writing the hearing-aid standard," said Berger, "and there've been about 100 engineers involved."

Generally speaking, the engineering community has been able to keep ahead of the problems, said Allen Taflove, a professor of electrical and computing engineering at Northwestern University. But how long that will continue is a question.

As engineering schools struggle with what they can include in the four years that a student has to prepare to be an electrical engineer, there's been a tendency to reduce requirements for courses in electromagnetic studies, Taflove said.

"There's so much to teach in only four years," he said, "and electromagnetics has been cut back at most of the major universities. Younger engineers just aren't trained in it anymore, and as the older ones retire, you wonder what will happen."

The world could find out the hard way, as transistors packed into ever-smaller spaces on computer chips begin to emit tiny radio signals that interfere with the chip's function, Taflove said.

"You have to design chips with exquisite care so the circuits don't jam themselves," he said. "It's very important, yet fewer schools even teach this anymore."

-- Homer Beanfang (Bats@inbellfry.com), February 14, 2000


The interference problem has, I believe, been one of the sources of threshold after threshold that chip designers have had to overcome. In other words, as designers keep making, e.g., CPU's, smaller and smaller, and denser and denser vis-a-vis packaging, the signal strengths used continue to also decrease.

As SolarMax gets rolling, and as we see bursts of energy of various frequencies pumped into our environment, this article may give hints of some of the harder-to-identify ways we may be affected.

-- Redeye in Ohio (cannot@work.com), February 14, 2000.

According to the solar flare chart I've been watching, the EMF (Electromagnetic Flares) have hit as high as 7.5 on the 12th, dropped to 2's & 3's on the 13th, and are again going up today 5's & 6's.

The highest this chart goes is an 8. I guess if they hit the 8, we're fried. But, then I am sure there's a government agency that will control this, right?

This is just like they're controlling everything else.

-- Richard (Astral-Acres@webtv.net), February 14, 2000.

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