The New Short-Range Networking Standard?

UWB Emerges as Challenger to Narrowband Signals in 5G Applications

Image Source: Pasko Maksim / Stock.Adobe.com

By Alex Pluemer for Mouser Electronics

Published February 18, 2022

“Connectivity” is a word you’ve probably heard a lot lately, and you’re going to be hearing it even more as the wireless industry upgrades to 5G around the world over the next few years. From smartphones to tablets to medical wearables, the devices we use every day will be wirelessly connected and exchanging information on an almost constant basis. Even the most technologically-challenged among us are familiar with Wi-Fi and Bluetooth. Still, there's another wireless communication protocol that is threatening to overtake them in the quest to be the “king of connectivity.”

Ultra-wideband (UWB), a wireless communication protocol that’s been around for more than a century, has been reawakened to compete with Wi-Fi and Bluetooth for the "connectivity" champion title. Although ultra-wideband refers to any signal equal or greater to 500MHz (or with a fractional bandwidth >20%), UWB typically operates between approximately 3.0GHz to 10.5Ghz, enabling it to transfer more significant amounts of data and making it less susceptible to signal interference than narrowband signals (like Wi-Fi). UWB is also cheaper and more energy-efficient than Bluetooth, and it’s an appealing alternative in short-range transmission scenarios, such as within an office building or manufacturing facility. This article will examine UWB's past, present, and future, and where it will fit into the world of 5G connectivity.

The Origins of Ultra-Wideband

The genesis of UWB can be traced back to the first wireless radio signal devices that utilized "spark gap" transmitters to communicate wirelessly. The devices could transmit sound through short electrical impulses over short distances, and this eventually led to radio wave transmission. In its infancy, UWB sent old-fashioned telegraph signals over large distances, such as messages to ships at sea. As the technology evolved, the higher frequency ranges UWB operates in made it an optimal method of transmitting large amounts of data, such as images or video files, over shorter distances. UWB might have become the original wireless communication standard, but it was outlawed for commercial use in 1920, becoming a proprietary protocol for classified government and military implementations. UWB remained out of bounds for public use until 2002, when the Federal Communications Commission in the US opened it back up for commercial applications. Since then, UWB has propagated into various technologies, including radar and location/positioning systems, medical devices and wearables, and consumer electronics. Apple included UWB tech in the iPhone 11 (released in 2019), enabling far more accurate positioning and ranging capabilities than previous iterations.

Where Ultra-Wideband is Now

The ongoing transition to 5G has been an inflection point in the adoption of UWB into networking and communication technology. UWB signals are transmitted either in short, quick pulses (measured in picoseconds) like the spark gap transmitters of old or in carrier waves like radio frequency (RF). Data transferred in pulses is transmitted by alternately turning the signal on and off—like the way lighthouses used to communicate with ships off the coast by flashing signals in Morse Code. It can require over a hundred pulses to transmit a single bit of data, but the high rate of speed at which the bits are transmitted (each pulse lasts fewer than 1.5 nanoseconds) enables data rates of up to 27Mb/sec. Carrier waves can also be created by modulating the signal to simulate an RF wave. UWB can transmit data over multiple frequencies at once and achieve much higher data rates than other wireless technologies. Implementing UWB with 5G networks can provide customers with faster upload/download speeds and greater bandwidth. 

Figure 1: A 5G-connected factory management network (Image Source: Blue Planet Studio / Stock.Adobe.com)

UWB is also the optimal solution for real-time tracking and positioning applications, whether they're in consumer electronics (like the iPhone), used to manage inventory or used to determine the location of products or equipment within a factory/manufacturing setting (Figure 1). UWB-enabled devices come equipped with MIMO (multiple-input/multiple-output) antennas miniature enough to fit into devices as small as smartphones or watches. When two UWB-enabled devices are in close enough proximity to connect, the devices begin "ranging," or determining their respective locations and distance from one another through a method called "time of flight." By sending a pulse from one device to another and measuring the time it takes the pulse to complete its journey, the two devices can determine their exact locations relative to one another. This is especially advantageous in indoor settings where GPS isn’t always as functional and Wi-Fi can struggle to break through solid objects and surfaces. If you're the type who's always misplacing their phone or who can never find the TV remote, UWB can pinpoint their respective locations in your home within inches.

Due to its short transmission period and small packet size, UWB is also found in applications that require lower latency and faster system response times, like gaming and training simulations. UWB’s low spectral density also helps prevent signal interference and makes UWB signals very difficult to detect, providing more security for data transmission. The additional security UWB provides is already being incorporated into digital car keys. Companies like BMW and Tesla are reportedly developing digital car keys that implement UWB for their vehicles to reduce incidents of signal relay theft from key fobs that transmit traditional radio signals.

The Future of UWB – Where Can It Go from Here?

Now that we know where UWB came from and where it currently stands, we can speculate on where it’s going. The most obvious potential is applications requiring high data transfer speeds, such as real-time video streaming. Security camera and traffic camera networks can provide much higher-quality video using UWB than other wireless communication protocols. UWB's lower latency makes it a good potential fit for vehicular automated driving systems cameras. To avoid collisions with other moving vehicles, automobiles with automated driving systems will be able to almost instantaneously share locations and the speed plus direction they're driving—other wireless protocols may be subject to signal interference or latency delays. This kind of data sharing between vehicles can also improve overall traffic flow and fuel efficiency by suggesting alternate routes to avoid delays, keeping traffic moving steadily and improving gas mileage. Sharing data between vehicles and general infrastructure is another potential benefit—ever been stuck driving around the big city on the weekend and can't find a place to park? A system by which parking structures communicate to motorists where and when open parking spots are available could make circling the block ten or fifteen times a thing of the past.

Personal medical devices can also be improved by implementing UWB, creating a personal wireless area network around a patient. Their heart monitor can communicate with their smartwatch to give the patient (and potentially doctors) real-time updates on the health of their heart. Forecasting heart attacks and other cardiac events could be greatly aided by having access to health-related data in real-time.

Figure 2: A mesh network of devices, vehicles, and infrastructure in a smart city (Image Source: Lesley Wang / Getty Images)

UWB's most significant potential, however, may lie in mesh networks: Ultra-connected systems with multiple devices constantly exchanging data (Figure 2). These mesh networks will allow devices to connect and automatically exchange and receive data. AI-powered algorithms might even be implemented to optimize data transmission by finding the fastest, most power-effective, lowest-latency path available. Data will flow through these networks the way electrical current flows through a resistance network, automatically finding the optimal path as the resistance increases or decreases. In implementations that require connected devices to be constantly in motion—for example, on a factory floor or a busy highway—these types of inter-connected systems could dramatically improve efficiency and responsiveness while providing greater security from interference or hacking than narrowband signals.

Conclusion

Although UWB technology is over a hundred years old, its potential in modern applications is still being developed. The interconnected world of 5G and the Industrial Internet of Things (IIoT) will require a lot of bandwidth, and UWB provides more bandwidth and faster speeds than narrowband signal protocols. In a future of smart homes, office complexes, and cities, competing signals will be flying everywhere. Fortunately, UWB can coexist with narrowband signals without causing interference while being more difficult to detect and hack than Wi-Fi or Bluetooth. Local area networks are just a jumping-off point for what UWB could become—it may be transmitting data to and from vehicles, traffic systems, and wearable devices very shortly. It’s easy to envision a future in which every consumer electronic device and vehicle is connected to a massive mesh network, relaying information in an ever-present, invisible sea of digital currents. In the new world of 5G, connectivity will be king—and UWB could be making a lot of those connections.