Taking the speed bumps out of Wi-Fi using FM

November 11, 2015 // By Jean-Pierre Joosting
The wireless Internet can be infuriatingly slow loading single Web page even with the fastest Internet speed available but during these all-too-frequent times, it seems like the connection barely works at all.

"Most people think it's a mystery," said Aleksandar Kuzmanovic, associate professor of electrical engineering and computer science at Northwestern University's McCormick School of Engineering. "They get upset at their routers. But what's really happening is that your neighbor is watching Netflix."

Most people don't realize how much their neighbors' Internet networks interfere with their own, heavily affecting speed and performance. Unless a home is located in the middle of nowhere, it is likely that neighboring homes' Wi-Fi networks will bump into each other and prevent data from getting through. This is particularly true in large, urban apartment buildings where many people reside within a smaller area.

Kuzmanovic and his PhD students Marcel Flores and Uri Klarman have found that problems caused by competing networks can be mitigated by using an already-existing, extremely cheap medium: FM radio.

"Our wireless networks are completely separate from each other," said Flores, the lead author of the study. "They don't have any way to talk to each other even though they are all approximately in the same place. We tried to think about ways in which devices in the same place could implicitly communicate. FM is everywhere."

Called "Wi-FM," the team's technique enables existing wireless networks to communicate through ambient FM radio signals. The team agreed that using FM was attractive for several reasons. For one, most smartphones and mobile devices are already manufactured with an FM chip hidden inside. FM is also able to pass through walls and buildings without being obstructed, so it's very reliable. Minor upgrades to software would allow devices to take advantage of Wi-FM.