How Australian Engineers Solved One Of Wireless Networking's ...

Engineers and scientists from CSIRO came together to solve a wireless networking problem. The result was WiFi.

You’re in an open-plan office, a hotel room or an airport lounge and you fire up your laptop. 

The next step is typically to click on the name of a WiFi network, maybe enter a password, and, that’s it: you’re online.

It’s simple — a completely unremarkable experience that, quite remarkably, connects you to almost any form of communication and any source of information you wish to access. It works in cars, in homes, in public parks, at beaches and even on aircraft. 

But a few decades ago, such communication was unheard of. 

That changed when a group of researchers at the CSIRO, led by engineer and physicist Dr John O’Sullivan, set themselves a momentous challenge.

“The signals going from the access point on the wall to a laptop would simply bounce around the room,” O’Sullivan tells create. 

“It’s like radio reverberation. If you’re trying to send bits, one after another, at 100 megabits per second, those bits are only about three metres apart. So the reverberation would do a pretty good job of scrambling everything.”

In the late 1980s, O’Sullivan was well known for his career in radio astronomy and radio and signal processing. His teams had developed radio and signal solutions for everything from geophysical imaging to proxy imaging detectors in mines. 

In the early 1990s, he brought together a team to work on wireless networking projects.

“My role was one of a generalist, because I knew just enough about each of the areas to argue with the experts,” he recalls. 

“We initially had a mathematician, a signal processing expert, a software person and a couple of different engineers. We argued about what the exact problem was and argued about different ways of solving it.”

The problem, it turned out, was creating a wireless network — but not just any wireless network.

“Wireless networks existed, but we thought we could create an indoor wireless network that was as fast as the best wired network at the time, which was a fibre optic network. That ran at 100 megabits per second,” O’Sullivan said. 

“What we set out to create was 100 times faster than any commercially available product.”

Within the group, the experts were optimistic. Outside the group, however, it was a different story. When they pitched the idea to organisations and external specialists, to other academics and to experts in the field, “people were polite about it, but some looked at us as if we had rocks in our heads,” O’Sullivan recalls.

The team took a set of steps that involved separating out different ‘tones’ of signal.

They had discovered, when studying echoes and reverberations, that when they sent signals of a different tone, some tones would make it through unscathed while others would be scrambled or blotted out.