Ultra-Wideband (UWB)
Here's everything you need to know.

Ultra Wideband is a fast, secure and low power radio protocol used to determine location with accuracy unmatched by any other wireless technology. How is it going to change your business? What is so attractive about UWB that Apple decided to add it to iPhones? Here’s everything you need to know about Ultra-wideband technology that is going to revolutionise our world.

Apple marketing chief Phil Schiller presenting the U1 chip for UWB in the iPhone 11

Apple marketing chief Phil Schiller presenting the U1 chip for UWB in the iPhone 11.

  • What is Ultra-wideband (UWB)?
  • How does UWB work?
  • How accurate is Ultra-wideband?
  • What is UWB range?
  • What’s the difference between UWB, Bluetooth, Wi-Fi, and RFID?
  • Is Ultra-wideband safe?
  • Ultra-wideband usecases
  • How much does UWB cost?
  • Ultra-wideband benefits
  • Ultra-wideband disadvantages
  • What’s next for UWB
  • How can you get started with Ultra-wideband?

What is Ultra-wideband (UWB)?

Ultra-wideband (also known as UWB, ultra-wide band and ultraband) is a short-range wireless communication protocol. It uses radio waves to enable devices to talk to each other. Sounds familiar? Yes, it is similar to Bluetooth but more precise, reliable and effective.

Although you may have heard about Ultra-wideband only in 2019 when Apple added UWB to iPhone but the technology has actually been around for decades. As early as 2002 U.S. Federal Communications Commission (FCC) authorized the unlicensed use of UWB. UWB saw limited use in military radars and was even briefly used as a remote heart monitoring system. Back then the cost of implementation and lower than initially expected performance limited the use of UWB in consumer products. Today ultra-wideband chips are cheap and small enough to put them inside other devices like smartphones. Nowadays it is so precise that iPhone owner can now point his or her phone at a friends phone to transfer a file or photo.

What makes UWB so unique? It transmits data across short distances and precisely determines location by measuring how long it takes for a radio pulse to travel between devices. As the name suggests, it also uses a wider frequency. The frequency range of Ultra-wideband is between 3.1 and 10.6 GHz. There is one drawback which is its short range, but that doesn’t matter much when you have two devices that are in a room together.

UWB Chip

Thanks to its characteristics, UWB applications enable a lot of new services for consumers and enterprises like accurate indoor location & positioning, providing context aware information and precise analytics in real time (see UWB usecases).

How does UWB work?

Like Bluetooth and Wi-Fi, ultra-wideband is a wireless communication protocol that uses radio waves. A UWB transmitter sends billions of radio pulses across the wide spectrum frequency and a UWB receiver then translates the pulses into data. The same way bats use echolocation to sense their environment, UWB pulses can be used to sense distances between two transmitters. The shorter the duration of the impulse, the more precise the distance measurement will be. UWB achieves real-time accuracy because as it sends up to 1 billion pulses per second (about 1 per nanosecond).

UWB Spectrum

UWB uses very low power and the high bandwidth (500MHz) is ideal for delivering a lot data from a transmitter to other devices. By sending pulses in patterns, UWB encodes information. It takes between 32 and 128 pulses to encode a single bit of data, but given how fast the bits arrive, that enables data rates of 7 to 27 megabits per second.

To increase UWB’s range and reception reliability, a MIMO (multiple-input and multiple-output), distributed antenna system has been added to the standard that enables short-range networks. The antennas can be embedded into a smartphone or other devices such as a wristband or smart key.

When a smartphone with UWB (like the latest iPhone) comes close to another UWB device, the two start ranging, or measuring, their exact distance. The ranging is accomplished through Time of Flight (ToF) the time it takes for a pulse to get from point A to point B.

Depending on the type of use, such as asset tracking or device localization, one of the UWB devices calculates the precise location of another UWB-enabled object – such as those car keys or television remote control that fell between the couch cushions. (If the device is running an indoor navigation service, the UWB-enabled device must know its relative location to the fixed UWB “anchors” and calculate its position on an area map).

How accurate is UWB?

UWB's low-power signals cause little interference with other radio transmissions and can effectively measure distance with an accuracy up to 10 cm (3.9 inches). Decawave’s UWB chip promises accuracy even up to 2 cm (0.78 inches) in indoor environments. To compare Wi-Fi and Bluetooth accuracy is only up to 1 meter (39 inches) provided there are no obstructions.

UWB precision animation

What is UWB range?

UWB can determine the relative position of other devices in the line of sight even up to 200 meters (656 feet) based on the IEEE 802.15.4a standard.

UWB indoor location

What’s the difference between UWB, Bluetooth, Wi-Fi, and RFID?

It is easy to get overwhelmed when choosing your own solution when there are so many different technologies to choose from. You may be asking yourself if UWB technology is actually better for your particular use case. Here is a summary of the main difference between UWB, Bluetooth, Wi-Fi, and RFID.

UWB vs. Bluetooth

At first UWB and Bluetooth may sound very much the same. Bluetooth LE (BLE) is a low power radio system that has been used in beacons for ranging and measuring location, or at least that was the promise many beacon producers were trying to sell. BLE technology is relatively not expensive and easy to implement. The problem is that with Bluetooth you can’t really measure location or distance. What you can do is to detect if a device like a smartphone is within a range of another device (for example beacon). Why is that? With Bluetooth you can only distinguish whether a signal is weak or strong and translate it to being close or far from a device.

It’s really not the same as measuring precise distance or tracking location. Some solutions promise to convert that signal strength to a distance estimate but the problem with this approach is that signal strength is a poor indicator of distance. If signal strength is low, that doesn’t have to mean the phone is far from the beacon but there is an obstacle between the beacon and the phone. Bluetooth and Wifi operate on the same frequency of 2.4GHz therefore their signals are highly prone to noise interference, they can easily be reflected or absorbed resulting in inaccurate data and low responsiveness. You may try to create a walkaround and use a mesh of beacons in fixed locations to take signal measurements every few meters to mitigate the problem of interference and increase precision. But those measurements are costly, time consuming to implement and not precise.

Ultra-Wideband, in comparison, provides a much higher accuracy (up to a few centimeters). In contrast to Bluetooth Low Energy, the distance it measures is not based on the signal strength, but the time it takes the signal to travel from point A (smartphone) to point B (UWB tag). UWB range is shorter compared to Bluetooth. Because Ultra wideband frequency is 3.1–10.6GHz there is limited probability of any signal interference which is often a case with BLE.

However, there are certain things where BLE beacons are still the preferred solution. They have been on the market since 2013 and easily available. BLE based solutions are also cheap and easy to integrate with any existing systems. All smartphones do have bluetooth technology integrated in them which is not yet a case for UWB.

# UWB Bluetooth (BLE Beacons)
Battery Low consumption Low consumption
Range up to 200 meters (656 feet) up to 70 meters (230 feet)
Accuracy 10 centimeters (3.9 inches) up to a meter
Cost Low Low
Best For Proximity Marketing, Customer Analytics, Indoor Navigation, Smart Homes, Factory Automation, Asset-Tracking, Logistics Proximity Marketing, Customer Analytics, Loyalty, Indoor Location

UWB vs. Geofence

Geofencing uses GPS signals from satellites and cell phone towers to establish your proper location. GPS accuracy is limited to 5 meters at the best possible scenario. This accuracy is even worse if you are inside a building as GPS signals are weaker inside a closed building. Using GPS has a big impact on the battery life of your mobile device. Geofencing does not work indoors and that is where Ultra wideband comes into place. UWB is currently the most precise way to establish location indoors. UWB is not only more precise than GPS but also much faster.

# UWB Geofence (GPS)
Battery Low consumption Moderate consumption
Range up to 200 meters (656 feet) no limit (outdoors)
Accuracy 10 centimeters (3.9 inches) 5 meters (16 feet)
Cost Low Low (no infrastructure)
Best For Proximity Marketing, Customer Analytics, Indoor Navigation, Smart Homes, Factory Automation, Asset-Tracking, Logistics Outdoor Campaigns, Outdoor Location, Customer Analytics


NFC is a relatively inexpensive RFID technology that operates in the 13.56MHz band and is becoming much more popular due to its low cost and size. NFC has a range of just 4 centimeters (less than 2 inches) therefore it can only be used in certain scenarios and establishing a precise location is not of them.

RFID is not able to estimate the distance which is one of the most important advantages of UWB over other technologies. What it can do is to tell you that two objects are within 4 cm of each other and that’s all. Passive NFC tags do not require any battery and are often incorporated into key fobs, payment cards or devices. One of the most popular use cases for NFC is to use it for contactless payments with a smartphone. An NFC tag that is created in a smartphone is then read by NFC reader in POS to establish a secure connection and pay for a product.

It is likely that UWB will win over NFC in many use cases as it has all pros of NFC. The only disadvantage is that you must broadcast a UWB signal, so UWB tags are more expensive than passive RFID tags.

Battery Low consumption No battery
Range up to 200 meters (656 feet) few centimeters
Accuracy 10 centimeters (3.9 inches) few centimeters
Cost Low Low
Best For Proximity Marketing, Customer Analytics, Indoor Navigation, Smart Homes, Factory Automation, Asset-Tracking, Logistics Loyalty, Delivering information at a tap, Security Checkpoints

UWB vs. Wifi

Wifi was the most common indoor-location technology before Apple announced iBeacon protocol in 2013. Wifi’s main advantage over UWB technology is its availability in public as well as private places all over the world. All smartphones are Wifi enabled as well which makes it a fairly easy choice for many companies.

The main Wifi disadvantage compared to UWB is the common approach to estimate distance or location by measuring only the signal strength. As described above for Bluetooth, signal strength is a poor indicator of distance. The accuracy of Wifi is limited to a few meters, which makes it unusable in many use cases. You can determine a room in which a worker is located in a factory building but you won’t be able to pinpoint his exact location.

WiFi requires much more power than UWB that is why all routers need to be plugged in to the power outlet at all times. Wifi routers are also much more expensive than cheap UWB tags nowadays.

While Wi-Fi has come a long way to allow greater accuracy in locating other devices and reducing the costs, UWB is more precise, uses less power and is much cheaper.

# UWB WiFi
Battery Low consumption AC (does not work on battery)
Range up to 200 meters (656 feet) up to 100 meters (330 feet)
Accuracy 10 centimeters (3.9 inches) few meters
Cost Low High
Best For Proximity Marketing, Customer Analytics, Indoor Navigation, Smart Homes, Factory Automation, Asset-Tracking, Logistics Proximity Marketing, Loyalty, Basic Customer Analytics

Is Ultra-wideband safe?

There are multiple aspects to discuss when analysing the safety of UWB technology. First of all the power of UWB pulses are 1/10000-1/100000 then those of signals emitted by mobile phones so it’s safe to be used by all people.

UWB has the ability to measure relative location of devices to levels of accuracy unmatched by any other wireless technology. When combined with highly secure, unique identifiers, it can protect vehicles from unauthorized access via two-factor authentication. A UWB enabled car can detect the presence of its owner, verify his identity and ensure that the communication between two objects, such as a car and its keys, is denied if the distance between them goes beyond a pre-defined threshold. This makes any fraud access really hard to perform if not impossible.

UWB Real Time Location Tracking RTLS

People also become more concerned about UWB used for background location tracking on their iPhones. The management of ultra-wideband use of location data is done entirely on the device. The location of the device is not collected by Apple, but locally by the iPhone itself.

Ultra-wideband usecases

With precise ranging UWB has an advantage in both precision and security over Bluetooth and WiFi and that advantage can be used in many different usecases. Based on FiRa Consortium initial focus is on three primary categories of use cases: hands-free access control; location-based services; and device-to-device (peer-to-peer) applications: UWB FiRa Consortium Usecases

  • Smart Car Access - unlock a car with a smartphone as soon as you approach it for keyless entry and remote start.
  • Secure Wireless Payments - it’s more secure than NFC and you can leave your smartphone in a pocket.
  • Secure Building Access - Automatically open doors to a secure area within a building once you approach them.
  • Smart Retail - provide useful information about a product you just picked up or special offer for buying one.
  • Asset Tracking - Boeing uses UWB tags to track more than 10,000 tools, carts and other items on its vast factory floors.
  • Sports & Fitness Tracking - NFL is already tracking players on a field for instant replay animations with UWB transmitters in each shoulder pad. A football's location is updated 2,000 times per second.
  • Wearable Health Sensors - Biometric UWB bracelet that monitors body temperature, oxygen saturation levels, body movement, heart-rate 24 hours a day.
  • Medical Radars - UWB pulses can be used to monitor respiration and heart beat of the person from a distance by reading reflected UWB signals.
  • Indoor Navigation - Get precise navigation indoor to your gate in the airport or a product on a shelf.
  • Smart Home - Lights, audio speakers, and any other connected device with UWB sensing capability will be able to follow users from one room to another, for example adjust the volume of a speaker based on where you’re standing or switch Netflix profile to yours.
  • Warehouse Positioning - Actively track people, machines and equipment indoors, accurate positioning in emergency situations - finding unconscious person.

How much does UWB cost?

Prices for Ultra-wideband kits have started to decline rapidly in recent years. They have reached acceptable level for testing not only in enterprise environments (factory automation, asset-tracking) but also in a much wider consumer environment (retail, office).

Ultra-Wideband two-way ranging evaluation kit from Decawave (MDEK1001) with 12 units costs $299. This kit allows you to deploy a Real Time Location System and evaluate the location performance of UWB technology. Decawave has also launched a BLE/UWB combo module with a built in accelerometer. The price is $25 a unit or less than $12 if you order more 10K quantities.

Estimote UWB Beacon

A complete UWB Beacon Kit from Estimote that consists of two units costs $149 but it is packed with state of the art IoT technologies. It has all the key wireless chips and sensors you need to build the next generation apps for the physical world.

Even smaller and more robust solutions are going to be revealed later this year.

Ultra-wideband benefits

UWB Benefits

  • Low Power Consumption - UWB is low power system, which is a key factor for mobile devices in terms of battery life and practical usability. A sensor that sends a pulse once every second is expected to work for seven years off a single coin battery.
  • High Precision - rather than depending on signal strength, UWB uses ToF (Time of Flight), TWR (Two Way Ranging), TDoA (Time Difference of Arrival), AoA (Angle of Arrival) techniques etc. to determine the distance from another device. With multiple antennas, UWB can also measure the angle the signal is arriving from. A precise angle combined with a precise distance means that your phone can pinpoint an object to a location in space.
  • No Signal Interference - UWB uses 3.1–10.6GHz frequency so there is limited probability of any signal interference which is often a case with Bluetooth and Wifi.

    UWB signal with noise
  • Ultra Fast - Bluetooth-based location sensing takes at least two seconds to get a fix on your location, UWB is thousand times faster which means that there is no lag and user experience is seamless.

Ultra-wideband disadvantages

The biggest disadvantage against UWB is that other technologies like Wifi or Bluetooth are able to interact with all today’s smartphones and tablets. But since Apple introduced UWB chip in its iPhone11 in 2019, UWB is expected to get into the mainstream really fast. Other smartphone makers are copying Apple and including UWB in their devices, and more importantly will include integration of UWB in location-aware electronics, wearable devices, and more.

What’s next for UWB

Currently only the iPhone has a built-in UWB chip but it is just the beginning of an ultra wideband revolution as other smartphone manufacturers are soon going to follow. The first Android smartphones with Ultra Wideband technology will be released later in 2020, according to Barclays analysts. Consumer electronics giants like Samsung and Sony, chipmakers Decawave and NXP, carmakers Volkswagen, Hyundai, and Jaguar Land Rover, and car electronics powerhouse Bosch have all announced their work on new devices that support UWB. Apple has also patented the use of UWB, or ultra wideband, to recognize when you're approaching your car to unlock its doors. Apple UWB car patent

It is also working on its own hardware called AirTags (iTag) that you will be able to attach to an object (like your keychain, wallet, or bag) and with your phone track the object’s location, perhaps even show you the location on-screen using Augmented Reality.

Although Apple supports UWB it has not yet opened the technology for other developers - this means that only apps that Apple created can take advantage of UWB. Enabling open access to UWB chip for all developers is something expected to happen later this year which will create a market of amazing apps powered with UWB location detection. According to Apple, “it’s like adding another sense to iPhone, and it’s going to lead to amazing new capabilities.”

UWB can potentially be used in everything from wireless printers to contactless payments. All this depends on finding that ‘killer app’ or function that makes it worth it. UWB doesn’t necessarily have to replace wifi, NFC, or Bluetooth—it can work with them.

How can you get started with Ultra-wideband?

If you are a developer and have some spare time, just buy one of the UWB Dev Kits and write an app to give it a go. If you prefer to save your time and test a ready to use UWB solution contact us now and we will help you get started. Bleesk is a global market leader in providing end-to-end proximity solutions.