17-11-2020 | | By Sam Brown
Recently, Renesas and Altran announced their development of the worlds first social distancing watch that can provide accuracy down to 10cm. What is ultra-wideband technology, what difficulties have social distancing measures faced, and how does the new device by Renesas and Altran overcome these issues?
The COVID-19 pandemic has dramatically changed society with the mass introduction of lockdowns and social restrictions, all of which have negatively affected the economy. If individuals could effectively keep their distance, as well as reliable tracking of those who have been in contact with COVID sufferers then there would be no need for lockdowns, and thus could allow the economy, and normal life, to return to normal.
One solution that has come close to achieving this is the use of contract tracing apps that run on smartphones that take advantage of Bluetooth radio modules. While some utilised GPS to track individual movements, Bluetooth allows for devices to communicate with each other, as well as providing better privacy options; not many users like the idea of being constantly tracked by app developers and authorities. However, even though contact tracing apps have been designed by many different organisations and companies, they are still to be adopted by the wider population.
The first technical hurdle faced by such apps is their inability to provide accurate distancing measurements. Technologies such as Bluetooth are good for low-range, low-bandwidth communication, but since devices can all use different transmitter powers, it becomes difficult to determine the distance between two devices. This also carries the issue that Bluetooth signals can bounce off objects resulting in reflections interfering with results.
The second technical hurdle faced by contract tracing apps is the privacy concerns that come with tracing. While many developers continue to assure the public that decentralised models protect privacy, a database containing unique identifiers still match up to users, and thus people can be seen to have made contact with other people by looking up keys which have been exchanged thus removing the ability to have private meetings.
Ultra-wideband, or UWB, is a radio technology that utilises a very large bandwidth (+500MHz) at very low energies. Traditional radio technologies occupy a narrow frequency band at proportionately high energy densities allowing them to operate at distance, but UWB achieves range and bandwidth in a different manner.
Firstly, UWB utilises frequencies between 3GHz and 10GHz, which see very little traffic when compared to other devices such as Bluetooth and Wi-Fi. This means that there is very little interference faced by UWB, and there are few devices which UWB can interfere with.
Secondly, the use of lower-energies means that the range of UWB is significantly lower than those that use traditional radio methods on the same frequencies. As a result, UWB is less likely to interfere with devices that operate on the frequency range UWB utilises.
Thirdly, the high-frequencies used by UWB are those that do not diffract well, and as such UWB relies heavily on line-of-sight. While this can be problematic for other radio technologies, UWB can take advantage of this to provide a radio technology that supports accurate positioning.
Recognising the potential need for social distancing hardware, Renesas and Altran teamed up to develop the worlds first social distancing watch. Most social distancing systems utilise Bluetooth for their ranging, but Bluetooth’s unreliability in positioning led Renesas and Altran to use UWB technology. The new watch, which utilises the Renesas Synergy S128 MCU, has an accuracy of less than 10cm, making it highly ideal for determining the distance between two wearers. The watch also boasts a range of other features including an HMI capacitive touch interface and consumes ten times less power than other UWB systems.
While no information regarding its commercial availability has been made, the announcement of COVID vaccines may see these devices be made quickly redundant. However, the technology used, and the designs themselves may be essential in future pandemics. The world’s population is still increasing, and with over 8 billion people on the planet, the chances for viruses to mutate and form also increases.
“After months of global pandemic shutdowns, people will want to feel safe when they return to work, school and social settings in close proximity to others. I’m pleased our collaboration with Altran is about responding to the COVID-19 pandemic with the first LRP UWB social distance wristwatch solution. Renesas plans to expand to more use cases in the future such as access control, asset tracking and geofencing.” – Roger Wendelken, Senior Vice President, Head of MCU Business, IoT and Infrastructure Business Unit at Renesas. “