Frequently Asked Questions
What is UWB technology？
Ultra-wideband (also known as UWB, ultra-wide band or ultraband) is a short-range radio technology that operates at low power over a large portion of the radio spectrum at once. UWB has traditional applications in non-cooperative radar imaging. Most recent applications focus on sensor data collection and high precision locating and tracking.
What are the differences between UWB positioning and GPS/BDS positioning？
The current GPS and BDS positioning systems rely on satellites, with positioning accuracy generally ranging from 3 to 10 meters. This approach only works when you have line-of-sight with the satellites and so doesn’t work indoors.
Why is UWB more accurate than RFID, bluetooth, ZigBee, WIFI and other indoor positioning technologies?
RFID, Bluetooth, ZigBee, Wi-Fi and other positioning technologies usually use signal strength to calculate and estimate the distance between the tag and the anchor. Signal strength is affected by various factors, such as power inconsistency during signal transmission, shape deviation of transmitting antenna, and shape deviation of receiving antenna, etc. as well as any sources of interference. These can all lead to unpredictable changes in the signal, resulting a large error in the ranging results. Therefore, the positioning accuracy of such systems is generally around 3 meters (or over 5 meters for RFID).
UWB uses the "Time of flight" (TOF) of radio waves to calculate the distance between the tag and each positioning anchor, which has nothing to do with signal strength and antenna. The positioning accuracy can reach 10cm, making it is the best choice for indoor precise positioning.
What is TWR？
TWR (Two Way Ranging) is an algorithm for two-way ranging. First, the tag transmits a signal to the anchor. The anchor receives the signal and then returns it to the tag. Finally, the tag sends a receipt of the data to the anchor. The anchor calculates the distance between the anchor and the tag by averaging the time the radio waves took to travel three times between the anchor and the tag (tag à anchor à tag à anchor).
What is TDOA？
TDOA (Time Difference of Arrival), is a time-difference based positioning algorithm. Each time the positioning tag sends a positioning broadcast signal, the system calculates its position based on the time difference between when the signal was seen by each anchor. This is also known as multilateration.
What is the difference between TDOA and TWR modes？
Power Use: In the TDOA system, the positioning tag can be dormant for most of the time. The tag only needs to wake up periodicall to send a positioning signal, which is received by all the anchors for positioning. The rest of the time the tag is asleep, saving power. In the TWR system, the tag is required to interact with each anchor 3 times. If there are 4 positioning anchors, the tag needs to transmit 12 signals for each positioning.
Spectrum Use: In TDOA, the tag is always active, which consumes relatively more power. Frequent signaling takes up the communication spectrum, reducing the number of positioning tags the system can support.
Accuracy: TDOA positioning accuracy is slightly lower than TWR due to some errors caused by clock synchronization and running.
Installation: TDOA requires clock calibration and synchronization between anchors, and the deployment and construction of the system is more complicated than the TWR approach.
How many anchors and tags does the positioning system require?
TWR mode theoretically requires at least 3 anchors. TDOA mode requires at least 4 anchors. Each set of anchors can support up to 1,000 tags, and the coverage should be determined according to the field environment. Generally, a set of anchors can cover an area of about 800 square meters. The more anchors, the higher the positioning accuracy and the larger the coverage area.
What is the positioning accuracy？
Theoretically, the whole positioning system can achieve 10cm precision. Considering power consumption, interference, network signal and other factors, it can typically achieve about 30cm in most scenarios.
What factors will affect the positioning accuracy of UWB？
Factors influencing UWB positioning can include metal shielding, wall shielding, refraction of glass and other items, temperature and humidity in the environment and other factors. Therefore, it is very important to accurately measure the positioning environment. In addition, by increasing the number of positioning anchors, the impact of shielding on the positioning accuracy can be largely avoided.
Why doesn't your UWB have a dedicated clock source？
TDOA requires time synchronization for each anchor. We use wireless time synchronization, which does not use a dedicated clock source system. Wireless time synchronization uses one anchor as the clock source and sends a clock synchronization signal to all other anchors. This avoids the need for a dedicated clock source.
Does the positioning system support 3D positioning？
Three-dimensional positioning requires the addition of one anchor in each group that is not in the same horizontal place as other anchors for height calculation. We can provide 3D positioning coordinate values where the customer requires this.
What is needed to set up the position anchors？
The anchors support both Ethernet and Wi-Fi for the transmission of positioning data. They can be powered from a DC power supply or using PoE (power-over-Ethernet).
What types of positioning tags do you offer？
Currently, we offer positioning badges, positioning wristbands, and goods positioning tags. Other customized forms can also be designed according to the requirements of the customer.
How do I charge the tags？
Currently, all positioning tags use a Micro USB charging port. Of course, this can be customized according to user needs, including other USB modes and wireless charging.
What are the requirements for the tag working environment？
Due to the influence of metal or other shielding, the positioning requires a relatively open and safe environment to avoid affecting the positioning accuracy. Please keep the temperature (0-60℃) and humidity in the working environment relatively stable.
How are the positioning results presented？
Positioning details can be viewed through the UbiTrack platform software. We also offer multiple interfaces to output positioning results, such as WebSocket, Restful API, PHP SDK and other forms. We can also integrate the working environment scenarios (2D or 3D graphics) provided by customers into the existing system for viewing. In addition, we can provide source code to facilitate users to integrate positioning map and display into their own GIS system.
What hardware customization options are available？
The hardware of the positioning system includes positioning tags and positioning anchors. We will customize the hardware according to the functional requirements of customers and the site topography, so as to ensure accurate positioning. Hardware customization includes functions, such as heart-rate tracking, environment monitoring, etc. The PCB design can be customized to offer alternative charging methods, etc. In addition, we can customize the housing of the badge and the anchors.
Is it possible to customize the software？
We can modify the software to meet the requirements of customers as long as this doesn’t compromise the core positioning ability.
Do you support commissioned OEM, R&D and production？
Yes, we can provide OEM, R&D and production offers.
Do you provide technical support services？
We always aim to satisfy customer demands to the greatest extent. From product design and research & development, to production and after-sales service, we assist customers with technical support and software services. We can also offer customized support services to match the customer’s requirements.
What is the price of the positioning system？
Every positioning system is customized according to customer needs. This means we will quote on a project-by-project basis. Variables include the number of anchors and tags, customization requirements, etc.
What are the advantages compared with other UWB positioning systems？
Low power: our company has many years of experience in the development and production of IoT products and has a number of patents in the field of embedded low-power consumption.
Multiple positioning algorithms: we support TWR and TDOA algorithms, giving you the flexibility to balance power use against required number of positioning tags.
Ease of deployment: we use wireless clock synchronization, making the system easier and cheaper to deploy. We also offer flexible install options for the positioning anchors.
Strong anti-interference: our positioning products adapt the positioning algorithm based on fitting, with stronger anti-interference ability.
Flexible use cases: the system offers many options for anchor management, tag management, area management, electronic fence setting and alert setting, real-time performance monitoring and other functions.
High-performance distributed architecture: the core positioning data is stored in a distributed MongoDB non-relational database, with strong scalability, and supports real-time query and summary of high-performance positioning data.
Highly-performant software: the positioning engine uses NodeJS with high throughput and asynchronous I/O, which supports real-time positioning at extremely high scale. The positioning system is based on a browser/server structure, and the frontend uses HTML5 for maximum flexibility.
Comprehensive API interface: all functions and data are accessible through our open API. This makes it easy for you to build your own applications on top of the positioning system.
Established company: we have been operating in the IoT space for many years. We sell a wide variety of products on the international and domestic markets, and our technology is leading the world.
What are the typical use cases for positioning products?
Warehouse logistics: track the location of stock in real-time. Monitor statistics and scheduling of warehouse equipment and materials.
Personnel management: Enable personnel positioning and physiological status monitoring for high-risk environments.
Patient monitoring: monitor the location and well-being of patients in hospitals and nursing homes.
Sports competition and training: precisely track players on the pitch to assist with training and analysis of play. Monitor the physiological status of users and improve safety for environments such as gyms.
Judicial supervision: real-time positioning tracking and physiological status monitoring of prisoners and police officers. The system can also enable virtual electronic fences that send an alert when a user enters an area that is out of bounds.