Anyone who’s had a cable or satellite TV subscription knows the problem - it’s frustrating and expensive trying to connect additional TVs around your home. Wireless technology seems the obvious answer, but until recently it was thought distribution of HD video over domestic wireless networks was impossible.

University of Bristol Professors David Bull and Andrew Nix have played a major role in developing the solution with technology that delivers high-performance wireless transmission of HD video to multiple devices around homes. The technology is now creating new revenue generating opportunities for media and technology companies, plus better and more flexible services for consumers.

The story started in 2001, when Professors David Bull and Andrew Nix in Bristol’s Faculty of Engineering established ProVision as a spin out company to exploit their existing research on wireless networks. Bull and Nix were driven by the belief that demand for high-quality video distribution in the home would increase dramatically - the recent explosion in multi-media content on tablets, laptops and smartphones has proven them right. They also believed that this would almost always involve some aspect of wireless communication. If this was the case, improvements to wireless transmission technologies would be needed.

“Off-the-shelf wireless technologies, such as the WiFi that many of us now use at home, are generally inappropriate for the delivery of real-time video,” says Bull. “The problem is that the strength and quality of wireless channels can vary from minute to minute, or even second to second, resulting in packets of data being delayed or lost. This results in significant reductions in visual quality. We realised that high-quality, error-resilient solutions that can adapt to those variable conditions were essential.”

The ProVision team developed a number of crucial innovations throughout the 2000s. In particular, Bull and Nix initiated the use and refinement of Wireless Local Area Network (WLAN) technology through the pioneering EU-funded WINHOME research project, which for the first time envisaged wireless connected televisions fed from a central gateway. Bristol was also heavily involved in another EU-funded project, WCAM, which developed new video-optimised packetisation and link adaptation strategies for robust video transmission.

After these initial successes, the real breakthrough came in 2009, when ProVision launched the world’s first wireless HDTV transmission system, AXAR1000, at the Consumer Electronics Show (CES) in Las Vegas. Built on the concepts developed in the WINHOME and WCAM projects, the AXAR unit could transmit TV pictures from a wireless gateway to multiple receivers around the home. Its unique features included dynamic real-time adaptation to wireless channel conditions in the home, plus the ability to send different channels to different rooms. It also featured video error fixing functionality that makes it unnecessary to resend packets of lost data, thereby preserving WiFi bandwidth.

The impact on the media and broadcast technology industry was immediate and the value of the product quickly recognised by leading industry executives.

“AXAR offers several benefits for the cable and satellite multiple-system operators,” says Nix. “Straightaway, they were attracted by the fact it’s a true multi-room solution which can extend HD multi-room viewing to portable devices - something that they previously thought to be impossible. They could see we were providing a new way for them to improve customer retention and increase revenue. The simple fact is that AXAR offers significant benefits for consumers - a multi-room HD TV solution without the cost, inconvenience and unsightliness of wired connections - so that has to be good for a cable company’s business.”

The original vision and commercial opportunity that the Professors saw back in 2001 is now a reality. ProVision was acquired in 2011 by Global Invacom, which has developed the 2009 ProVision CES demonstrator into a wireless HDMI product available through Amazon, eBay and other mass market retailers. Launched in 2012, the product includes an integrated 802.11n system with antennas optimised for video. In 2013, Global Invacom also launched a new HDLive product based on ProVision technology, which enables viewing on modern tablet and mobile devices.

Global Invacom’s R&D collaboration with the University of Bristol has continued through the Arkive in Your Pocket project, developing very low complexity robust video technology for large scale events. Bull and Nix continue to work with Global Invacom, in fields such as digital signage, and extensions for larger scale public spaces and enterprise environments.