Mexico. A group of researchers led by a BYU computer engineering professor has created a protocol that significantly extends the distance a Wi-Fi-enabled device can send and receive signals.
The engineering innovation doesn't require new hardware to improve the signal range for "internet of things" devices, such as a door sensor or motion detector, but it can extend the distance of these devices from a WiFi access point by more than 60 meters, according to the test results.
"That's the really cool thing about this technology: it's all done in software. In theory, we could install this on almost any Wi-Fi-enabled device with a simple software update," said Phil Lundrigan, assistant professor of computer engineering at BYU.
The new protocol is called Noise On/Off Communication and is programmed just above the existing WiFi protocol using the same hardware. While Wi-Fi requires speeds of at least one megabit per second (1 Mbps) to maintain a signal, the "ONPC" protocol created by Lundrigan and his co-authors can maintain a signal as low as 1 bit per second, one-millionth of the data rate required by WiFi.
Beyond Wifi; a for noise
To do so, Lundrigan, Neal Patwari of Washington University (in St. Louis) and Sneha Kasera of the University of Utah adjusted the transmitter on a WiFi-enabled device to send wireless noise in addition to data. They programmed into the WiFi sensor a series of 1s and 0s, essentially turning the signal on and off in a specific pattern. The WiFi router was able to distinguish this pattern from the surrounding wireless noise (from computers, TVs, and cell phones) and thus know that the sensor was still transmitting something, even if the data was not received.
According to Lundrigan, 1 bit of information is enough for many Wi-Fi-enabled devices that simply need an on/off message, such as a garage door sensor, an air quality monitor, or even a sprinkler system. During their research, the authors successfully implemented their ONPC protocol, along with an ingeniously named application to manage the protocol ("Stayin'Alive"), ultimately extending the range of a commercial device 67 meters beyond the range of standard WiFi.
Main implications now and in the future
The researchers made it clear that their ONPC protocol isn't meant to replace Wi-Fi or even long-range wireless protocols like LoRa, but is meant to complement WiFi. Specifically, only when Stayin' Alive detects that the WiFi device has lost its connection, it starts transmitting data using ONPC.
That said, the authors believe the innovation could make LoRa more far-reaching or be used over other wireless technologies. "We can send and receive data regardless of what WiFi is doing; all we need is the ability to transmit energy and then receive noise measurements," Lundrigan said. We could apply this to cell phones or Bluetooth as well."
The research was presented Oct. 22 at the International Conference on Computing and Mobile Networks in Los Cabos, Mexico.
