UWB versus other location technologies

Choosing the right location technology for your business is fundamental to successful results. Each location technology has its own pros and cons. This blog compares Pozyx’s ultra-wideband (UWB) technology to other location technologies, so you can make the right choice for your business. Ultra-wideband is an ultra-accurate and cost-effective location solution for indoor positioning.

• UWB versus GPS
• UWB versus RFID
• UWB versus BLE
• UWB versus camera-based positioning
• UWB versus Wi-Fi Positioning Systems (WPS)
• UWB versus LIDAR
• Conclusion

UWB versus GPS

GPS is a well-known location technology and is used daily by millions of people. Its most significant disadvantage is that it does not work indoors, and GPS repeaters often result in significant errors. Ultra-wideband technology on the other hand is made for indoor positioning and does not encounter the same challenges as GPS indoors.

UWB location data can also be combined with GPS location data in the new Pozyx Platform. The platform is compatible with GPS conform the omlox standard, and thus able to combine the Pozyx ultra-wideband signals with GPS signals. This way, tracking assets from indoor to outdoor and the other way around with a seamless transition has never been easier.

UWB versus RFID

RFID, or Radio Frequency Identification, uses radio waves to wirelessly send or receive information. The system uses labels with unique information that are attached to a person or object. With RFID it is important to distinguish active from passive RFID, as the two work differently.

UWB versus Passive RFID

With passive RFID, the tag has to pass a gateway before it gets positioned. There is no real-time positioning. These tags are cheap, as they don’t have their own energy source and only activate when they receive a radio signal from the antenna.

A well-known everyday application of RFID is NFC, a subset of RFID that works at a higher frequency. It is used for example in the access doors on metro stations, where you have to scan your card with an NFC chip on the NFC reader to make the doors open.

When it comes to finding assets, passive RFID is ill-suited. Not only does passive RFID have a 3% error margin, but also if an asset is lost, it mostly would not have passed the gateway, meaning it did not activate and also did not send out any location information. With ultra-wideband, the tags are transmitting information at a higher frequency and are being positioned in real-time, making your assets visible all the time, in the entire building.

In our Bonduelle case study, it becomes clear that ultra-wideband and passive RFID can work together seamlessly. While Bonduelle already used RFID to keep track of their pallets, they still misplaced and lost countless pallets per year. By installing the Pozyx system and attaching the industrial tags to their forklifts, they knew which assets were picked up and dropped off at what points, resulting in a 3% efficiency gain.

UWB versus Active RFID

In active RFID systems, the labels have their own power source which permits the label to transmit data continuously, making real-time positioning possible. It gets up to 3 meters (or 10 feet) precise, whereas ultra-wideband technology has an accuracy of 10-30 cm (4-12 inches). An enormous difference. Furthermore, active RFID has a failure rate between 5% and 20%. Considering these challenges, and the higher cost of active RFID, ultra-wideband is the better option here, both performance and cost-effective wise.

UWB versus BLE

Bluetooth is a highly adopted communication technology and is used in everyday life for numerous wireless devices. Headphones, wireless mouses, keyboards, and speakers all use Bluetooth to connect to our smartphones and laptops.

Bluetooth Low Energy, or BLE, was introduced in 2010. It uses the same technology as regular Bluetooth but, as the name suggests, uses significantly less energy to communicate with other devices. Its most common uses reside in smart devices, asset tracking, and indoor positioning.

BLE was not initially designed for indoor positioning and is more of a by-product of the technology. It works by calculating the position of the BLE tag through the signal strength received by multiple beacons. This is called RSSI (receive signal strength indicator) and is not the most efficient measurement tool. It has an accuracy of 2-5 meters and is only 90% of the time effective, whereas ultra-wideband technology can reach a positioning of 10 to 30 cm accuracy. This is because the ultra-wideband system does not measure the position through signal strength but through Time of Flight (ToF). It calculates the time it takes for the radio wave to travel between the tag and the anchor. The Pozyx system calculates this for at least three anchors and positions the tag at the intersection of the three distances, this is called trilateration.

UWB is thus better suited than BLE for industrial environments, where small mistakes can cost lots of money.

UWB versus camera-based positioning

Camera-based positioning is highly accurate, but also very expensive. There are different types of camera-based position, visual light positioning (VLP) and optical motion capture. Both systems are mostly used academically and do not have a lot of industrial use cases.

UWB versus Visual Light Positioning

Visual light positioning can work with any camera, such as the one on your smartphone. The camera is generally aimed at the ceiling, where a system is installed that emits light with different codes depending on the location. This system is very accurate, but not scalable. Ultra-wideband technology on the other hand may be a little less accurate than VLP, but is more scalable and suited for large industrial sites because it positions using radio waves. Except for the anchors which are attached to the ceilings or walls, there is no need to change the infrastructure of the indoor space that needs to be monitored, and there are almost no limits on how large the monitored space can be.

UWB versus Optical Motion Capture

Optical Motion Capture detects the slightest movement with millimeter accuracy and is thus very precise at positioning. It is mainly used in sports and in the entertainment industry, less for locating objects, but for detecting movements of performers. This technique requires a lot of calibration, is expensive, and is, like VLP, not scalable to large spaces.

UWB versus Wi-Fi Positioning Systems (WPS)

Wi-Fi has, since its first release, become one of the most important communication technologies in the world. A few years after its first release, it became one of the first technologies used for indoor positioning. Wi-Fi is still an effective technology for indoor positioning today, but its suboptimal accuracy makes UWB more suited for precise localization.

Wi-Fi indoor positioning either uses the existing infrastructure or custom-installed sensors. Both have a typical accuracy of 5-15 meters, as opposed to the 10-30 cm that can be achieved with ultra-wideband technology.

Types of Wi-Fi positioning

There are several techniques used for Wi-Fi positioning. Multilateration and fingerprinting use a measure called the received signal strength indicator, similar to BLE positioning. This is easy to implement but does not convey stable and accurate positioning, as RSSI is vulnerable to objects or people moving around.

The other WPS technique uses Time of Flight (ToF) and Angle of Arrival (AoA), the same technique as is used with ultra-wideband technology. Using Time of Flight with Wi-Fi positioning may result in higher accuracy than the RSSI method, but since Wi-Fi was not made for this, it is often not cost-effective. The Pozyx UWB positioning system was made and programmed for accurate real-time positioning with the Time of Flight and Angle of Arrival method, and will lead to a more cost-effective and accurate solution.

UWB versus LIDAR

LIDAR, or Light Detection And Ranging, works with a rotating laser to measure the range and angle to obstacles. Its most used application is on self-driving cars. The way LIDAR works, makes it more ideal for mapping than for locating the absolute position of an object. Certainly in industrial environments, UWB is more fit for positioning.

Conclusion

While there are many location technologies, ultra-wideband technology is in most cases the go-to method for accurate real-time positioning in industry 4.0. In this table, the previously discussed points are summarized.

Interested in learning what accurate positioning can mean for your business? Schedule a call with one of our RTLS experts, they are ready to advise and inspire you with our use cases.

State of UWB - 7 Trends that are the key drivers for the UWB success

This Pozyx ebook describes the State of UWB in 2022 and the 7 Trends that shape the RTLS landscape. It explains the benefits of the UWB technology, the key players, standardization bodies and alliances, semiconductor companies and academic UWB research projects. In short, find out why UWB is as successful as it is today.

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