| Written by Mark Buzinkay
(3) What technology can be used for RTLS?
RTLS technology is a system that can be used to identify and locate objects in real time, mostly through the use of sensors, tags, and wireless networks. The RTLS system typically includes both active and passive elements, such as wireless radios, infrared cameras, ultrasound, and magnetic fields.
Active RTLS technology uses sensors to detect and track objects in real time. For example, ultra-wideband (UWB) radio signals and infrared sensors both use energy to track objects. UWB radio signals can be used to track both stationary and moving objects, while infrared sensors are used mostly for stationary objects. Other active technologies, like magnets, use magnetic fields to track objects.
Passive RTLS technology, on the other hand, involves tags to track objects. These tags can be placed on the object or a nearby surface. These tags rely on RFID, barcodes, or other methods to uniquely identify objects and transmit their location information to a central database.
Finally, both active and passive RTLS systems also use wireless networks to transmit data from the sensors and tags to a central database. The most common wireless networks for RTLS systems are WiFi and cellular networks.
Overall, RTLS technology is an incredibly powerful tool for tracking and locating objects in real time. By combining active and passive sensors, RTLS tags, and wireless networks, RTLS systems can create a highly accurate map of the environment. Let's examine the technologies that provide RTLS functionality.
(3.1) Bluetooth Low Energy
Real-time location systems (RTLS) are a type of asset location technology that uses Bluetooth Low Energy (BLE) to track the position of assets and people in real time (1). RTLS is becoming increasingly popular for a variety of applications, from retail to healthcare, and its wide range of capabilities makes it versatile and powerful.
With BLE technology, a BLE tag sends a radio signal to a BLE receiver, which then communicates with the tag's unique identifier to determine the asset's precise location. These tags are perfect for tracking smaller assets like inventory, medical devices, and personnel due to their small and lightweight design.
The versatility of BLE tags is unparalleled, with a range of shapes and sizes to cater to various needs. There's a BLE tag for every situation, from wearable tags for personnel tracking to stationary tags for walls, doors, and shelves. Moreover, these tags can transmit real-time location data to a network of receivers, ensuring pinpoint accuracy and asset tracking.
BLE tags communicate with receivers using a beacon protocol, which allows for precise asset tracking within a pre-defined radius. Additionally, these tags can be customized to transmit supplementary data like temperature, humidity, and vibration readings, providing valuable insights into an asset's condition and location. By leveraging this technology, RTLS systems can offer businesses and organizations an unparalleled view of their assets, leading to enhanced tracking and visibility.
With BLE technology at its core, RTLS systems offer businesses and organizations a comprehensive view of their assets, enhancing tracking and visibility. Moreover, these systems are relatively easy to install and maintain, making them an alluring option for organizations of any size.
(3.2) GNSS/GPS
GNSS/GPS (Global Navigation Satellite System/Global Positioning System) is a satellite-based navigation system designed to provide accurate, real-time location information. It is composed of a network of 24 satellites that broadcast signals that receivers on Earth can receive. The signals can be used to identify the position and velocity of an object or individual (3).
For RTLS (Real Time Location System), GNSS/GPS signals are combined with additional data sources such as Wi-Fi, Bluetooth, and RFID to provide more precise and accurate location information. This enables RTLS systems to determine the exact location of an object or person in real time, allowing for greater operational efficiency and improved safety. In addition, some RTLS systems combine GNSS/GPS with other technologies, such as dead reckoning and inertial navigation systems (INS), for even greater accuracy.
Such RTLS systems can be used in many different applications, such as fleet management, asset tracking, and retail and security applications. They are often used in conjunction with other GPS-based systems, such as GIS (Geographic Information Systems), to provide more accurate and comprehensive tracking.
The accuracy of RTLS systems depends on the quality of the satellite signals and the specific applications they are used for, but in general they are far more accurate than traditional methods of tracking people, vehicles, and objects. This makes them an invaluable tool for businesses across a range of industries. Whether it’s managing a fleet or tracking the movements of shoppers in a store, RTLS systems are a cost-effective and reliable solution.
(3.3) Infrared Radiation
One of the most important components of RTLS is infrared radiation, which can be used to identify objects and perform precise tracking. Infrared radiation is a type of electromagnetic radiation emitted by the sun, other stars, and warm objects on Earth. Infrared radiation has wavelengths that range from 7,000 to 12,000 nanometers (nm), which makes it invisible to the human eye but can be detected by certain instruments. This type of radiation lies in the range of the electromagnetic spectrum between visible light and microwaves. It can be used to provide precise position information since walls or other obstacles cannot obstruct it.
Infrared radiation is important to real-time locating systems (RTLS) because it can’t penetrate walls, furniture, and obstacles, making it ideal for tracking objects in closed areas without external visibility. RTLS systems use infrared signal transmitters to send out energy pulses that reflect off the environment and back to receivers placed in strategic locations. The reflected signals are then interpreted by the RTLS software and used to accurately track the location of objects or people.
By using infrared radiation, RTLS systems can provide precise tracking with minimal interference from other sources or devices. This is why infrared technology is often used in environments like factories and warehouses where traditional vision-based tracking technologies may be too difficult or impractical to install and maintain.
(3.4) Passive RFID
Passive RFID is a type of radio frequency identification (RFID) technology which is powered by the energy of a sensor’s signal, rather than a battery or other external power source. Passive RFID solutions are popular in RTLS because they are cost-effective and reliable. They are favoured in environments where subsequent readers can be used to pick up their signal.
The most common type of passive RFID technology is called backscatter. This technology works by reflecting the energy from an incoming signal from an active reader back to the reader. When the reader receives the signal, it can be used to identify the passive RFID tag and provide the reader with data about it.
Passive RFID tags are generally composed of a small antenna and a microchip. The antenna is used to pick up the signal from the reader, and the microchip stores information about the asset in the tag attached. Passive RFID tags can be used to track and identify a wide range of objects, including people, vehicles, and animals.
When used in an RTLS system, passive RFID tags are used to locate assets in real time. They are particularly useful in industrial settings, such as in warehouses, manufacturing plants, and hospitals, where they can be used to monitor inventory, quickly locate items and track personnel.
In addition to providing a reliable way to track and manage assets, passive RFID tags are also environmentally friendly and cost-efficient. They require no batteries, making them cost-effective to use in large-scale applications, and they don’t generate radio frequency radiation.
(3.5) Active RFID
Active RFID is a powerful technology that enables asset tracking and monitoring of people, animals, and things in real time. As part of Real-Time Location Systems (RTLS), active RFID uses a network of tags, readers, and other devices to instantly identify and locate items (2).
Active RFID tags are placed on various items and contain a battery-powered radio transmitter. These tags are configured to transmit signals carrying specific information through radio waves to readers, which are connected to a computer system. The readers communicate with the tags and back to the computer system to detect the signal of the tag in the vicinity, thus forming a basis for asset tracking.
The systems work on the basis of triangulation, known as trilateration. As such, active RTLS RFID systems require multiple readers placed around the area being monitored. Whenever a tag is detected by one of the readers, its signal is calculated through triangulation, and its exact location is determined. Moreover, active RFID readers can be installed in a variety of ways, including indoor or outdoor, and fixed or mobile.
Active RFID systems provide higher accuracy than passive RFID systems. They are typically used in healthcare asset tracking, facility access control, and asset management applications. Some of the benefits of active RFID include faster asset tracking, improved accuracy and scalability, reduced costs, and improved safety.
Active RFID is a reliable and cost-effective solution for real-time asset tracking and monitoring applications. With a variety of readers and tags available, active RFID provides a versatile and flexible system for asset management, security, and other purposes.
Learn more about Asset tracking RFID software!
(3.6) Ultrasound radiation
Real-time locating systems (RTLS) rely on ultrasound radiation technology to accurately track the position and movement of objects and people. By emitting high-frequency sound waves from a transducer, the system detects the object and picks up reflections through a receiver. This provides real-time information on the exact location of the object or person being tracked.
Ultrasound radiation is one of the most efficient and reliable methods available for tracking people and objects in RTLS applications. It is non-invasive, safe, easy to use, and cost-effective. With ultrasound radiation, it is possible to detect objects with pinpoint accuracy regardless of environmental conditions such as poor lighting, cluttered environments, or inclement weather. Ultrasound radiation can also detect multiple objects simultaneously, making it an ideal solution for applications with many tracked items.
Although ultrasound radiation has many benefits when used in RTLS applications, there are some drawbacks as well. For example, it can only be used to track objects within line-of-sight, which means that obstacles such as walls can block its effectiveness. Additionally, sound waves travel through air at relatively slow speeds, so in larger areas, it can take several seconds for the data to be transmitted from transmitter to receiver, which can cause delays in real-time tracking applications.
(3.7) Ultra-Wideband
Ultra-wideband (UWB) is a form of wireless communication technology that has gained popularity in recent years (4). Unlike other forms of traditional narrowband communications, UWB utilizes extremely low-power, high-frequency radio waves to send large amounts of data over short distances. This has made it an ideal solution for Real-Time Location System (RTLS) applications, where precise geolocation accuracy is a must.
To understand how UWB works, let’s first examine the frequency spectrum used. The spectrum ranges from 3.1 to 10.6 GHz, which is much higher than the 2.4 GHz widely used for Wi-Fi and Bluetooth devices. The wider range allows for a larger transmission range and faster speeds compared to its narrowband counterparts, making it ideal for RTLS applications such as tracking assets or personnel in real-time scenarios.
Another key benefit of UWB is its ability to accurately detect fine movements, such as footsteps and hand motions, due to its extremely high-resolution capabilities. Additionally, thanks to the very low power requirements of UWB technology, it can be used without interfering with other wireless networks in the same area – a critical advantage when implementing RTLS solutions indoors.
Finally, thanks to its robustness and immunity to external interference such as walls or metal equipment, UWB has been found to be particularly reliable when integrating into existing networks or systems that may be using existing wide area solutions and traditional RF technologies. This makes it an invaluable tool for enterprises looking to upgrade their RTLS solutions without introducing too many disruptions or changing their existing infrastructure.
(3.8) Wi-Fi
Wi-Fi is a type of radio technology used to transmit data between devices such as computers, smartphones, tablets, and other enabled electronic devices. It is often used as a way for people to access the internet when away from their home or office. RTLS (real-time locating systems) are a type of system that utilizes Wi-Fi in order to track the location and movements of objects or people within a certain space.
Wi-Fi RTLS solutions use a network of wireless access points or “nodes” throughout an area where the object or person needs to be tracked. These nodes create wireless coverage areas and can detect wireless signals that are emitted by the tracked objects, such as smartphones, smartwatches, or any other device with an active Wi-Fi connection. The nodes then record the signal strength and other related data in order to determine the position of the tracked object relative to the node locations. This data is then sent back to a central controller which can be used to analyze the collected information.
Wi-Fi RTLS solutions offer many benefits over traditional GPS tracking, such as faster response times, better accuracy at close range, and cost savings due to not needing dedicated GPS receivers. Additionally, they require minimal infrastructure setup and greater scalability than GPS systems because more nodes can be added easily (5).
(3.9) Chirp
Chirp is a powerful wireless communication technology that employs Chirp Spread Spectrum (CSS) to locate and track people, assets, and devices across large-scale facilities, both indoors and outdoors. With its long-range performance, high reliability, low power consumption, and resistance to radio interference, Chirp is ideally suited for use in large, noisy environments like industrial facilities.
Similar to other communication protocols such as UWB and Bluetooth, chirp employs a wideband modulation technique to transmit data between devices using radio waves, generating linear frequency-modulated signals known as chirps.
Chirp operates in the 2.45 GHz ISM band and boasts the same category as other Spread Spectrum technologies. Initially designed for military applications, it ensures secure and reliable communication, making it more difficult to detect, jam or interfere with signals. Spread Spectrum methods spread radio signals across a wider range of frequencies, producing signals with wider bandwidths while still preserving the initial signal power.
Chirp pulses are an innovative solution for wireless communication, allowing seamless transmission and reception between transceivers and multiple devices. By analyzing incoming pulse patterns, receiving devices can translate them into valuable data, facilitating reliable communication over long distances.
But the benefits don’t stop there - chirp pulses can also be utilized for precise location sensing, enabling chirp-enabled devices like RTLS anchors to pinpoint the exact location of transmitting devices such as asset tracking tags. This technology opens up a world of possibilities for location-aware communication and services, making it a game-changer for industries like logistics and transportation.
Chirp technology is a versatile tool that goes beyond real-time device positioning. It can also facilitate two-way ranging, distance monitoring, and wireless communication applications. These features enable location-aware solutions for various industries, including asset tracking, collision avoidance, vehicle tracking, industrial automation, and worker search and rescue. Chirp technology is applicable in different types of facilities and industrial environments, such as factories, underground mines, warehouses, and more.
KEY TAKEAWAYS FROM THIS CHAPTER
- BLE technology works by transmitting an ultra-low power radio signal from a BLE tag to a BLE receiver.
- For RTLS (Real Time Location System), GNSS/GPS signals are combined with additional data sources such as Wi-Fi, Bluetooth and RFID to provide more precise and accurate location information.
- Infrared radiation can penetrate walls, furniture, and obstacles, making it ideal for tracking objects in closed areas without external visibility.
- Passive RFID is a type of radio frequency identification (RFID) technology which is powered by the energy of a sensor’s signal.
- Active RFID is a type of radio frequency identification (RFID) technology which is powered by the tag itself (see also: RFID for asset tracking).
- Ultrasound radiation uses high frequency sound waves that are emitted from a transducer to detect objects and track their movement.
- UWB utilizes extremely low power, high-frequency radio waves to send large amounts of data over short distances.
- Wi-Fi RTLS solutions use a network of wireless access points or “nodes” throughout an area where the object or person needs to be tracked.
(4) RTLS: How does positioning works?
When using RTLS solutions, it is important to understand the process of received data and granulation. Received data refers to the data gleaned from sensors placed around a given environment. Sometimes, these sensors are called satellites. This data can come from various sources, such as radio-frequency identification (RFID) tags, Wi-Fi access points, or Ultra-wideband (UWB) technology. The data is then passed to a base station, which is responsible for collecting, processing, and transmitting it to the RTLS software.
The data is then analysed and broken down into smaller, more manageable chunks of information called "granules". Granules are used to provide concrete, detailed data about objects in the environment, such as their exact location, speed, direction, and other relevant information. Granules are typically stored in databases and can then be used to generate reports or other forms of analytics.
(4.1) Trilateration
RTLS use various methods, including trilateration, to allow users to track the location of objects and people accurately. Trilateration is one of the most widely used RTLS technologies.
Trilateration is a powerful technique that utilizes multiple reference points to precisely determine the location of an object or person. By measuring the distances between three distinct reference points, a trilateration algorithm is able to accurately calculate the exact position of the target based on the known locations and distances.
Trilateration is based on a simple but powerful concept. In three-dimensional space, the distances between three known points (the reference points) uniquely determine the position of a fourth point (the object or person). If the object’s position can be calculated from a distance between each reference point, it can be accurately located in real time.
Trilateration stands out as one of the most potent tools in the arsenal of RTLS technologies. It is a dependable, precise, and effortless way of locating objects or people in a three-dimensional space. Trilateration technology is widely applicable across diverse fields ranging from inventory tracking, asset management, and asset protection to personnel tracking. Moreover, it can be combined with other RTLS technologies like RFID or Wi-Fi to provide a comprehensive tracking system.
(4.2) How accurate is an RTLS system?
When it comes to accuracy, RTLS is second to none. RTLS systems leverage a series of sensors and protocols to pinpoint a device's exact location in real time. This enables the system to identify a device's exact location within a few centimetres, making it one of the most accurate location tracking systems available.
The accuracy of an RTLS system is determined by a variety of factors and depend on the type of sensor network used, the number of devices in the system, and the environment in which the system is deployed.
It is important to note that RTLS systems are not infallible, and can be affected by environmental interference like an RF jammer or a dense metallic environment. However, these systems are designed to be robust and can quickly detect interference and reconfigure to maintain accuracy.
Overall, RTLS systems are incredibly accurate, making them an ideal solution for businesses looking to provide precise and reliable location tracking. By leveraging this technology, businesses can save time and money while also ensuring that their assets are always accounted for.
(4.3) Case Study 2: TTI Algeciras
In just ten years, TTI Algeciras managed to become one of the Top10 performing container terminals worldwide. Their relentless focus on process optimization, a committed workforce and top-notch technologies like the Terminal Tracker solution helped them to become a very successful player in the international shipping industry.
Do you want to continue reading about TTI Algeciras and the successful deployment of RTLS principles in a port? Then click on the image ...
KEY TAKEAWAYS FROM THIS CHAPTER
- Trilateration works by using three or more points of reference and measures the distances between them.
- Location indicators are often referred to as locators, trackers, transponders, or simply “tags”.
- The accuracy of an RTLS system is determined by a variety of factors and depend on the type of sensor network used, the number of devices in the system, and the environment in which the system is deployed.
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Sources:
(1) Lorenc A, Szarata J, Czuba M. Real-Time Location System (RTLS) Based on the Bluetooth Technology for Internal Logistics. Sustainability. 2023; 15(6):4976. https://doi.org/10.3390/su15064976
(2) B. Ding, L. Chen, D. Chen and H. Yuan, "Application of RTLS in Warehouse Management Based on RFID and Wi-Fi," 2008 4th International Conference on Wireless Communications, Networking and Mobile Computing, Dalian, China, 2008, pp. 1-5, doi: 10.1109/WiCom.2008.1249.
(3) Kumar, S., Moore, K.B. The Evolution of Global Positioning System (GPS) Technology. Journal of Science Education and Technology 11, 59–80 (2002). https://doi.org/10.1023/A:1013999415003
(4) Šinko S, Marinič E, Poljanec B, Obrecht M, Gajšek B. Performance-Oriented UWB RTLS Decision-Making Approach. Sustainability. 2022; 14(18):11456. https://doi.org/10.3390/su141811456
(5) X. Ma and T. Liu, "The application of Wi-Fi RTLS in automatic warehouse management system," 2011 IEEE International Conference on Automation and Logistics (ICAL), Chongqing, China, 2011, pp. 64-69, doi: 10.1109/ICAL.2011.6024685.
Note: This article was updated on the 29th of May 2024
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