UWB

UWB – The First Choice for RTLS and Smart Homes

UWB Stands Out with Great Precision and Many New Applications

Ultra-WideBand Technology

Ultra-wideband or UWB is a radio technology for short-range applications. It achieves high precision in location determination at low transmission power.

UWB is often equated with RTLS, a technology for indoor-positioning. In the past, this was certainly true. However, new application areas have emerged in recent years. More and more end devices now contain UWB chips.

UWB can do much more than just precise localization.

What is UWB?

UWB is characterized by low transmission power combined with a wide frequency range (between 3.1 and 10.6 GHz in the U.S. and 6.0 and 8.5 GHz in Germany). It is not based on modulated radio waves that transmit coded data, as is the case with other radio technologies. UWB transmits information in the form of weak individual pulses. The transmission power is limited to 10 nanowatts and the pulses are sent approximately every few nanoseconds, allowing UWB to achieve real-time accuracy.

Although UWB is active in the same frequency range as many other radio technologies (for example WLAN, Bluetooth, mobile communications), it does not generate any interference within the band due to the low transmission strength. The same applies in the reverse case: UWB transmissions are not interfered with by other transmissions. This makes UWB a very reliable technology.

Transmission Method ‘Overlay’

The transmission method of UWB is called 'overlay' or superposition, because the pulses of the transmitted signal overlay the signals also present in the frequency band. The receiver filters the incoming signals by pulse shape instead of frequency as is usually the case. To avoid interference from multipath propagation, the signals are synchronized.

Short Range

The range of UWB is relatively small, since there must always be an undisturbed line of sight between the transmitter and receiver. UWB transponders have a range of up to 20 meters indoors, up to 35 meters from some manufacturers, and up to 200 meters outdoors. UWB transponders have actually been used up to now for shorter measuring distances and as a cable substitute.

Service Life of a UWB Transponder

The permitted power of a UWB transmission is a maximum of 0.5 mW when the entire band is used, although it is usually lower. Almost all implementations use less than 1,000 MHz bandwidth, corresponding to a maximum of 0.074 mW. For comparison: a 4G/LTE cell phone transmits with a power of 200 mW. The battery life of a UWB transponder can therefore be more than 3 years. While in a warehouse the tracking process is carried out at a frequency of 1 Hz, in a high mobility scenario a transmission frequency of 1 kHz is required. In this case, the battery life is drastically shortened.

UWB is considered a key technology in warehouse management. The radio signals are robust and real-time accurate.

For the editorial support of the article "Ultra-wideband technology the first choice for RTLS and Smart Home" we would like to thank:

Carl Fenger

Technical Communications Manager

Legic Identsystems

Ron Jäger

Executive Manager Sales

Winckel

Michael Kaiser

Director Product Management & Innovations

Kathrein Solutions

Precise Real-Time Location with UWB

UWB in Industry and Logistics

UWB is known as a technology for real-time localization (RTLS) at close range. Compared to other radio technologies, UWB achieves a higher position accuracy of up to a few centimeters. This is achieved because it is not the signal strength but the signal propagation time between the transmitter (the UWB transponder or tracker) and at least three receivers (called anchors) that is measured.

The UWB transponder transmits a signal that is received by all nearby anchors differently depending on the distance. The time difference is multiplied by the constant speed of light in space and the coordinates of the transmitter are calculated.

The localization accuracy is particularly advantageous in environments where GPS/GNSS signals are blocked (e.g. indoors). In these applications, it enables the location and tracking of goods as they are transported within warehouses and production facilities. UWB also partly takes over the functions of an RFID tag. BMW, for example, uses UWB on the production line. Skoda and SCANIA track their industrial trucks with UWB to avoid congestion, to increase safety and to create transparency between warehouse and shop floor.

The Future

UWB is understood as a key technology in the factory of the future. Above all, the robustness of the signal and the fact that numerous use cases can be implemented with this wireless technology make it very attractive.

Ron Jäger, Executive Manager Sales, Winckel, explains. "Some vendors, us included, have added UWB to their expertise in process automation with auto-ID technology. For end-to-end data capture and process reliability, Winckel relies on a hybrid mix of different technologies and connects them using the AMIA software suite we deploy. Customer feedback from our first workshops has been very positive, as UWB is another technology that helps our customers reduce the number of manual processes."

Combination: RFID and UWB

Michael Kaiser, Director Product Management & Innovations, Kathrein Solutions, explains why the combination of RFID and UWB technology often yields real benefits: “While RAIN RFID has long been used in industry and in logistics as a cost-optimized identification method, localization based on UWB is still a relatively new topic in the auto-ID industry. However, when used correctly, the Kathrein K-RTL system can bridge the gap between low-cost RFID tagging and highly accurate localization with UWB.

The synergy of UHF RFID, NFC and UWB in the K-RTLS transponder allows the position of containers or industrial trucks to be precisely recorded, while continuing to use the existing RFID infrastructure to protect the investment made”, so Michael Kaiser's explanation.

In industrial applications, UWB has a high positional accuracy

Electronic devices that contain UWB chips can be controlled and operated with a UWB-enabled smartphone.

Smartphone Applications

Smart Home technologies offer intelligent functions and are becoming more widespread. The offer comfort, control of devices and increasingly support decision-making.

UWB and Smart Homes

Smartphone Applications

Since 2019, iPhones, some Samsung smartphones, some Lenovo laptops, Microsoft smartphones and the Google Pixel Phone are equipped with a UWB chip. The applications for it are extensive and diverse. Instead of a key fob whose RFID signal can be mirrored, making car theft easier, the phone can now open and start the car. There are mobile payment applications using UWB: just recently, the ING Bank teamed up with NXP Semiconductors and Samsung to test the industry's first UWB-based peer-to-peer payment application.

It is called NEAR, and people can use it to transfer money by simply pointing their phone at another person's smartphone. The application will enter its next pilot phase in the summer of 2022. Apple also uses UWB for AirDrop: file transfers are initiated with UWB, which then connects for faster transfers. Apple's AirTag is also based on UWB.

The Smart Home

RTLS trackers can be easily combined with sensors for smart home applications. The UWB chips from Novelda in Norway are used in a baby monitor.

Together with motion and breathing sensors, the monitor measures minimal movement or lack of movement, respectively, and helps prevent Sudden Infant Death Syndrome. Adults can use similar devices to detect sleep apnea.

The Chinese smartphone manufacturer Xiaomi offers smart home applications via smartphone. UWB-enabled devices immediately appear in a control display when the smartphone is pointed at them. TVs, speakers, but also vacuum robots, the air conditioner or kitchen appliances can be addressed in this way. The UWB chip turns the smartphone into a kind of universal remote control.

UWB Potential in Smartphones

Carl Fenger, Technical Communications Manager, Legic Identsystems, describes the benefits as follows: “Indoor navigation enabled by UWB RTLS in combination with mobile credential management has huge potential in office buildings, hospitals, shops, airports, industrial and logistical environments. It is a relatively untapped technology that will revolutionize human-infrastructure interactions just as GPS did 30 years ago.”

Interview

Impressed by Positioning Accuracy

RFID & Wireless IoT Global spoke with Tim Harrington, Chairman of the UWB Alliance, about the organization's history and goals.

INTERVIEW WITH TIM HARRINGTON

1. The UWB Alliance is a comparatively young organization. When and why was it founded?

The UWB Alliance celebrated its inaugural meeting in March 2018. I was the chairman of the IEEE 802.15.4z Task Group, where we worked on improving the UWB standards. When there were only about 6 months left until the .4z standard was published, several companies from the Task Group decided to continue working together in a new forum. This was the beginning of the UWB Alliance.

2. Which goals does the UWB Alliance pursue?

As an organization, our goal is to effect regulatory change in the U.S., the EU and other regulatory regions. I am also vice chairman of the European ETSI TGUWB, where we also focus on UWB.

The Alliance is dedicated to expanding the regulatory environment for UWB products and developing coexistence strategies for sharing spectrum with other RF devices and services. Members and staff are also working with the IEEE.

3. Since you mention sharing spectrum with other RF devices – does UWB cause interference?

That's not the case, but I can understand why you might think that. These bands are already occupied by so many users. But UWB is different. Most technologies use modulated radio waves as carriers for encoded data. UWB is extremely low-power, transmitting small units of information with nanosecond- long pulses that overlap other transmissions. Because UWB pulses generate noise similar to that of a computer, they can easily coexist within the frequency band.

The pulse method ensures that UWB signals do not interfere with other wireless technologies and resist their interference. This is what makes UWB so robust.

4. What can UWB be used for then?

When the technology was first approved in the early 2000s, it was used for small-scale applications. Much of it was industrial and some was used in sports. With the IEEE 802.15.4f standard, UWB was used for sports tracking in all NFL stadiums. The NFL tracks the players and the football. The ball is tracked about 2,000 times per second as it is thrown through the air, and the players are tracked about 12 times per second. So tracking has been a key application. However, with integration into smartphones by virtually all major manufacturers, the range of applications has greatly expanded.

5. Why is UWB more successful at tracking than other technologies?

It's just extremely accurate. I was working on tracking with broadband technology at a company called WhereNet, which was acquired by Zebra Technologies. This technology operated in the 2.4 GHz band, so it looked like RFID, but it could do so much more than RFID. Together with AIM, we called it Real Time Locating Service, RTLS. That was the beginning for industrial and military applications as well as logistics. At that time, I was very excited about the high locating accuracy. At 2.4 GHz, we could only be accurate to within 30 cm, but today we are talking about an accuracy of about 1 cm with UWB.

6. Are there other uses for UWB besides tracking?

Yes, of course! UWB is now very wide- spread. iPhones have had UWB since series 11, and Samsung devices are also UWB-enabled. Instead of a key fob, the phone can now open and start the car. Mobile payments are currently being tested with UWB. Apple is also using UWB for AirDrop and the AirTag. There are also many smart home applications.

7. Is UWB still used in industrial manufacturing?

Yes, UWB transponders are especially used in automotive manufacturing. BMW, for example, uses it on the assembly line. Different vehicles come onto the line, and the torque settings on the cordless assembly tools have to be different for each of them. That is why the vehicles have UWB tags on the front. The UWB system identifies the individual vehicle and sends a message that automatically adjusts the torque settings on the line for that type of vehicle, which saves a lot of time.

8. So what would you say: Is the story of UWB a success story?

It really looks that way at this point! Until 2019, only several tens of thousands of UWB chips and devices were sold per year. Demand has grown tremendously. In 2020, the iPhone 11 sold 64 Million units by itself. Adding the 12, 13 and the Samsung 21+ it is measured in hundreds of millions.