The vast range of Wi-Fi-enabled devices available today means that anyone could have several personal electronic devices all trying to connect to a network simultaneously. Multiply this by many hundreds of people in a busy public place with Wi-Fi connectivity and this often means that available bandwidth is greatly reduced. To help address this problem, researchers at Oregon State University claim to have invented a new system called WiFO that incorporates infrared LEDs to boost the available Wi-Fi bandwidth by as much as ten times.
As a general rule-of-thumb, most modern Wi-Fi systems provide a similar amount of bandwidth, and with one or two devices connected they are able to transmit and receive data very quickly. However if many devices are connected to a system at once, the available bandwidth has to be divided between all the connections and soon wireless data traffic slows down, resulting in the inevitable consequences of reduced playback speeds and slower page loading.
Add to this the plethora of Wi-Fi connected devices from digital cameras through to wireless headphones and even remote-controlled cookers becoming increasingly available, and the problem of reduced Wi-Fi bandwidth is only getting worse.
The new Oregon State system aims to help alleviate this problem by enhancing the available bandwidth by providing hybrid connectivity as both radio frequency (RF) and optical data links from the same source.
Dubbed "WiFO" (as a hybrid of Wi-Fi and Free-space Optic), the prototype system takes advantage of improvements in LED technology to allow for high-frequency modulation of infrared light in wireless transmission as part of an optical Gigabit wireless LAN.
"Using light to transmit signals is an old technology that dates back when the Roman soldiers communicated with each other using a simple flash code with mirrors," says Thinh Nguyen, associate professor of electrical and computer engineering at Oregon State and lead researcher for the project.
Using low-cost, off-the-shelf components, the prototype Oregon State device is able to transmit data at around 100 Megabits per second (Mbps), but the LED component is only able to transmit into reception areas around a meter in diameter. To overcome this limitation, the system switches automatically between a number of LED transmitters (designed to be attached to a ceiling or other high point), and the existing Wi-Fi RF, to provide seamless overall coverage of a particular area.
Also utilizing readily available components in the receiving system, the receivers incorporate simple photodiodes to pick up the infrared data transmissions. Basically just connected to a data receiver in the prototype, the team envisages that photodiodes and a little supporting circuitry in a commercial model would allow connection to a USB port for use on mobile devices or computers.
"We believe that if this technology takes off, the next generation of laptops would include a photodiode receiver," says Nguyen.
The original idea for the system was first theorized in discussions among associate Professor Nguyen and his university co-worker, Alan Wang, who is assistant professor of electrical and computer engineering at Oregon State. Nguyen and Wang collaborated on a project to see their ideas come to fruition, and tasked graduate students with constructing the first prototype.
In only eight months the students built and proved their concept and the team has recently been granted a provisional patent for their device. Associate Professor Nguyen is now looking to find a company to work with him and his team to develop the product and bring it to market.
"I wanted all of my student to contribute to this project, because I think it’s going to be big," Nguyen predicts.
Source: Oregon State University
