MIT demos wireless tech for VR headsets

Research shows future VR headsets could be free from tethers

The Massachusetts Institute of Technology (MIT) has shown off a prototype that will enable users of virtual reality (VR) headsets to use the devices wirelessly.

The system, dubbed MoVR, enables untethered communications at multiple gigabits per second using high-frequency radio signals.

The challenge of creating wireless VR headsets is twofold: the battery adds weight and heat and requires frequent recharging; and extremely high bandwidth is needed to convey the detailed images from the computer to the headset.

The system developed by the team at MIT's Computer Science and Artificial Intelligence Laboratory (CSAIL) uses special high-frequency radio signals called millimetre waves (mmWaves), technology that may be deployed in 5G smartphones.

"It's very exciting to get a step closer to being able to deliver a high-resolution, wireless VR experience," said MIT professor Dina Katabi, whose research group has developed the technology.

"The ability to use a cordless headset really deepens the immersive experience of VR and opens up a range of other applications."

Researchers tested the system on an HTC Vive headset, one of the most popular on the market owing to its use on PCs via the Steam gaming service, but said that it can work with any headset.

One problem with conventional wireless technologies, such as WiFi, is that they cannot support advanced data processing.

"Replacing the HDMI cable with a wireless link is very challenging since we need to stream high-resolution multi-view video in real time," said Haitham Hassanieh, an assistant professor of electrical and computer engineering at the University of Illinois at Urbana Champaign, who was not involved in the research.

"This requires sustaining data rates of more than 6Gbps while the user is moving and turning, which cannot be achieved by any of today's systems."

VR platforms have to work in real time, meaning that the systems also can't use compression to accommodate the inadequate bandwidth.

However, mmWaves technology has a number of limitations, most notably the requirement for a constant line of sight between transmitter and receiver.

MoVR therefore uses what CSAIL calls "programmable mirrors" that can reconfigure automatically to ensure that there is always a line of sight from the computing device to the VR headset.

"With a traditional mirror, light reflects off the mirror at the same angle as it arrives. But with MoVR, angles can be specifically programmed so that the mirror receives the signal from the mmWave transmitter and reflects it towards the headset, regardless of its actual direction," said Abari.

Each MoVR device consists of two directional antennas that are each less than half the size of a credit card. The antennas use what are called phased arrays to focus signals into narrow beams that can be electronically steered in microseconds.

The next step is to make the devices smaller and therefore more practical. This may take time but, given the huge impact that VR is expected to have in numerous markets, including gaming, it will no doubt happen eventually.