EVEN THE CHEAPEST laptop no longer needs a cable to access the internet; you just walk into a place and, somehow, magically, the device you are carrying connects automatically with a Wi-Fi hot spot. This happens in cafes, at home, on a train, on a plane. Wi-Fi routers are everywhere, to the point where it feels odd when you find a spot where you actually can't find a Wi-Fi hot spot to watch movies, stream music, search the internet, or do emails.

The name “Wi-Fi” is the trademarkpopularized by the Wi-Fi Alliance to describe radio systems used to access the internet, with billions of devices now connected and growing. Wi-Fi uses a set of industry standards adopted by the Institute of Electrical and Electronics Engineers or “IEEE,” a body that not only promulgates standards, but also records patents relevant to Wi-Fi. By now Wi-Fi-related patent families number a few hundred; but one stands out.

This is the story of the core patent, the one that showed how to make fast and efficient Wi-Fi. The patent journey took 25 years, and it took many twists and turns. In the end, it is a tale about how much hard work is involved in taking a great idea to market, how long it takes, and how, often, obtaining a patent may be merely the first salvo in a long war of attrition.

The story began with a small group of scientists in Australia, working in the esoteric field of radio astronomy. They were searching for gravitational waves associated with exploding black holes. That research lead to the filing in August 1987 of a patent application for “A Transform Processing Circuit,” for a semiconductor chip that could perform two types of signal processing on data streams: Fast Fourier Transforms (FFT) and Inverse Fast Fourier Transforms (IFFT). The inventors were employees of CSIRO, Australia's primary scientific research body.

It's not clear whether the researchers who were named on the patent ever thought that the invention would be significant in communications, but a few years later one ofthose researchers,John O'Sullivan, was involved in a commercialization project at CSIRO.