Ultra Wide-Band Indoor Positioning Explained – Everything You Need to Know Before Implementing

Ultra Wide-Band indoor positioning is one of the most recent emerging technologies in the localization space. It supersedes baseband, impulse and carrier-free technology. The United States Department of Defence was the first to use the term “ultra-wideband” before the technology became commercially available in the late 1990s. Today, UWB radio is a spectrum access method that provides high-speed data rate communication over the personal area network space.

According to the Federal Communications Commission, UWB positioning is defined as an RF signal that occupies a portion of the frequency spectrum greater than 20% of the center carrier frequency or has a bandwidth greater than 500 MHz.

UWB is a communication channel that spreads information over a wide portion of the frequency spectrum. This allows transmitters to send large amounts of data while consuming very little energy. Location tracking uses the time difference of arrival (TDOA) of RF signals to obtain the exact distance between the reference point and the target.

Modern indoor positioning systems rely on transmitting extremely short pulses and use techniques that cause a spreading of the radio energy (over a wide frequency band) with a very low power spectral density. This high bandwidth offers high data throughput for communication. The low frequency of UWB pulses enables the signal to effectively pass through common obstacles such as walls, furniture and other objects.

How Does Ultra Wide-Band (UWB) Indoor Positioning Work?

UWB gives a sixth sense to your devices. These signals work on a spatial scale ranging from NANO to Personal Area Networks (PAN). By design, UWB operates nearby and over a wide bandwidth due to its low-pass spectral density. It adheres to the 802.16.5 standard and communicates easily with peer devices.

The technology employs pulse radio to transmit a large bandwidth in short cycles while minimizing power consumption. It uses high pulse repetition rates to increase localization accuracy and data rates by transmitting more pulses per second. Conversely, reducing pulse repetition rates improves ranging performance, making the technology highly suitable for radars and imaging.

Localization with UWB

Rather than relying on a received signal strength indicator (RSSI), UWB measurements are based on Time of Flight (ToF) and Angle of Arrival (AoA). To improve trilateration accuracy, three or more receivers are necessary, but maintaining a line of sight is even more vital. UWB tags emit pulses containing ID, ToF and timestamp data. Nearby nodes detect and forward this signal data to the tracking source for processing. ToF measurements help determine the distance and orientation of tags within a few centimetres.

There are three main areas of use for localization:

• Communication and sensors
• Positioning and asset tracking
• Radar

UWB positioning techniques can provide real-time precision tracking for many applications. Examples include mobile inventory management, locator beacons for emergency services, an indoor navigation system for blind and visually impaired individuals, instrument tracking and military reconnaissance. These indoor position tracking signals provide highly accurate location estimations for complex environments.

Because UWB provides an accuracy rate that can reduce errors to sub-centimetres, it is easily one of the most suitable choices for critical applications requiring pristine precision. is easily one of the most suitable choices for critical positioning applications that require highly accurate results.

Technical Features of Ultra Wide-Band

The above example shows how the spectral density of UWB fares compared to other short-range communication protocols. UWB stands out due to its high bandwidth of 500Mhz. It operates efficiently in a signal-dense environment with almost no interference. It performs at frequencies ranging from 3.1 to 10.6 GHz and requires transmission power ranging from 0.5mW to 41.3 dBm/MHz. Within a 10-meter radius, UWB signals have an effective line of sight range of 10-150m and a high data rate of 1Gbit/s.

Ultra Wide Band consumes low power in comparison with other positioning systems that enable power efficiency for better battery life of devices. UWB localization uses pulses that allow transmitters to send only during the pulse transmission which in turn produces a strict duty cycle on the radio to minimize the baseline power consumption.

Why has Ultra Wide-Band Indoor Positioning Gained Attention Recently? 

In general, the high data rate of UWB indoor positioning systems can reach 100 Megabits per second (Mbps), making it a remarkable solution for near-field data transmission.

The high bandwidth and extremely short pulse waveforms help reduce the effects of multipath interference. They also facilitate the determination of TOA for burst transmissions between the transmitter and the corresponding receiver, which makes these setups far more reliable than older technologies. The length of a single pulse determines the minimum differential path delay, while the period pulse determines the maximum observable multipath delay to unambiguously perform multipath resolution.

In addition, the low frequency of UWB pulses enables the signal to pass effectively through physical barriers, drastically improving accuracy. UWB provides a high accuracy rate that minimizes errors down to sub-centimetres. Due to the rapid increase in market demand, technology companies are heavily exploring new opportunities to leverage the advantages of ultra wide-band technology to create highly innovative indoor positioning solutions.

UWB vs Other Positioning Technologies

Unlike infrared and ultrasound sensors, UWB does not strictly require a line of sight and remains unhindered by external noise or other communication devices due to its signal modulation. Furthermore, the equipment is relatively affordable and consumes less power than comparable alternatives like Bluetooth beacons.

Breakthroughs in indoor positioning systems explain why we now see so many commercial implementations of ultra-wideband technology. One well-known example is the Ubisense system. In this setup, a user carries tags that transmit UWB signals to fixed sensors, which then determine the user’s position using the TOA method.

According to a report published by the TechNavio market research company, the market for indoor positioning services grew at a compound annual growth rate of 29.7% between 2014 and 2019.

Today, modern indoor positioning systems are powering dynamic experiences in hospitals, shopping malls, airports, museums and athletic training centres. To meet surging market demand, industry leaders such as Mapsted are capitalizing on this momentum to deliver cutting-edge indoor positioning solutions.

Legal Concerns with UWB Indoor Localization 

While UWB indoor localization offers incredible advantages, applications must limit their operation to short ranges within a wide frequency spectrum to reduce the probability of interference. To regulate this, there are both license-exempt (unlicensed) and individually licensed frameworks. Many jurisdictions have adopted license-exempt frameworks, including the United States, the European Union and many Asia-Pacific countries. These frameworks require the application of special masks and operational conditions. Globally, regulatory bodies are generally aligned in reserving parts or the entirety of the 3100 to 10,600 MHz band for these extensive applications.

In the United States, there are strict bandwidth and power spectral density requirements. The National Telecommunications and Information Administration (NTIA) regulates the transmission frequencies. One of the main challenges of implementation is avoiding the transmission of signals outside the approved spectrum. Many countries will not provide frequency allocation for a new device unless it strictly adheres to NTIA guidelines or equivalent local compliance laws.

Strengths of Ultra Wideband Indoor Positioning 

License-free

One primary advantage of using an indoor navigation system powered by UWB is that it is often license-free due to its low power footprint. UWB is not officially classified as radio equipment because its low-power signal does not interfere with most existing radio systems.

Low Power Consumption

UWB consumes exceptionally low power compared to other frameworks, ensuring better battery life for connected devices. It uses pulses that allow transmitters to activate only during transmission, producing a strict duty cycle that minimizes baseline power usage. Furthermore, the communication complexity is shifted away from the transmitter and onto the receiver, saving energy at the source.

Large bandwidth

A massive bandwidth provides frequency diversity that makes time-modulated UWB (TM-UWB) signals resistant to multipath problems and interference. Because TM-UWB has a low probability of interception and detection, its use is incredibly prominent in military and defence applications.

Unhindered by obstacles

UWB signals penetrate better through obstacles (such as walls, furniture and people) than conventional signals while achieving the exact same data rate. However, due to strict power restrictions, some common setups may occasionally face difficulty penetrating thicker concrete walls.

The reflections from objects and surfaces near the path between the transmitter and receiver tend not to overlap in time because of the very short pulses. This gives UWB a highly desirable direct resolvability of multipath components.

Ultra Wide-Band Indoor Positioning Weaknesses

Although ultra-wideband indoor positioning has undeniable strengths, it does carry a few weaknesses. Misconfigurations can sometimes cause interference with nearby systems operating in the ultra-wide spectrum. In the US, the frequency range of 3.1 to 10.6 GHz overlaps with popular communication products like WiMAX and digital TV. In some regions, it may also interfere with legacy 3G wireless systems.

There are also minor concerns that certain devices may cause harmful interference to GPS and aircraft navigation equipment. To overcome this, engineers utilize techniques like Detection and Avoidance to eliminate conflicts with sensitive services.

Interference can also travel in the opposite direction. A UWB system’s signals may spread over bandwidths that contain the frequency of an existing narrowband system. This interference can be minimized by using minimum mean-square error (MMSE) multiuser detection schemes to reject strong narrowband disruption. Additionally, simultaneous ranging among too many UWB tags may cause channel access control problems, which can weaken overall accuracy.

Finally, while using very short pulses has distinct advantages, the receiver requires signal acquisition, synchronization and tracking to be performed with incredibly high precision relative to the pulse rate. These computational steps can be time-consuming.

What’s Better than UWB?

While UWB positioning provides high accuracy positioning in addition to many other features (E.g., license-free, low power consumption does not interfere with most of the existing radio systems, large bandwidth and high data rate communication), UWB positioning technology may affect GPS and aircraft navigation radio equipment and can also cause interference to the existing systems that operate in the ultra-wide spectrum. In comparison to other technologies Mapsted has analyzed, UWB tracking systems have emerged as one of the leading technologies for indoor positioning and have been used in a plethora of applications. Mapsted uses a revolutionary algorithm to leverage a variety of positioning systems and provide the world with the only indoor positioning system that doesn’t rely on the use of Bluetooth beacons, WiFI or UWB signals.

Real-World Applications

Beyond theoretical use cases, modern indoor positioning solutions utilizing UWB are actively transforming various industries. In the healthcare sector, hospitals heavily rely on indoor position tracking to locate critical medical equipment and monitor patient behaviour in real-time. Similarly, retail environments use these advanced tracking systems to analyze foot traffic and optimize store layouts for better customer experiences.

The Future of UWB Localization

As smart buildings rapidly become the global standard, the demand for highly accurate indoor positioning solutions will only continue to grow. Future advancements will likely focus on minimizing hardware footprints and seamlessly integrating UWB capabilities directly into everyday IoT devices. This natural evolution will firmly cement UWB as a cornerstone technology for any sophisticated spatial awareness platform.

How is UWB Different From Other Positioning Technologies?

To understand how UWB positioning works, it helps to contrast it with GPS. While GPS is synonymous with outdoor navigation, indoor environments present unique challenges that older technologies fail to address. That is precisely why the industry emphasis has shifted. Whereas traditional short-range communication protocols have flatlined in capability, UWB remains consistent and highly adaptive. While immovable obstacles, people and signal interference drastically reduce Bluetooth and Wi-Fi data rates, they do not severely impact UWB devices or their ability to perform trilateration.

Concluding Thoughts

UWB transmissions involve very short pulses, offering a massive advantage in resolving multipath components. The technology is incredibly appealing due to its distinct advantages over Bluetooth Low Energy and Wi-Fi. However, despite its ability to deliver an accurate location, it cannot function without dedicated hardware. Deploying at least three receivers is critical for high precision. Because it still largely relies on line-of-sight signals for optimal performance, it can sometimes lag behind an even more advanced, hardware-free Mapsted’s Indoor Navigation. We believe our technology outperforms UWB to provide the best location experience possible, but don’t just take our word for it; listen to our clients. Get a free demo today for an exclusive look at our technology. If you found this blog helpful, please read our blog on “Indoor Positioning Technology: Everything You Should Know About It” or watch our video on “How Does a Wi-Fi Positioning System Work?”