How RTLS Works

Real-Time Location Systems (RTLS) are advanced technologies that track and identify the real-time location of objects, assets, or individuals within a specified area. For a more detailed introduction to RTLS, you can refer to our previous article What is RTLS. Here, we’ll focus on how RTLS works, breaking down the core components and the technology behind these systems.

The Core Components of an RTLS System

Understanding how RTLS functions requires knowledge of its main components:

• Tags: These are small devices attached to the items or people being tracked. They contain a transceiver that communicates with the anchors. Tags can be active, semi-passive, or passive, depending on their power source and the technology used. Active tags have their own power source, enabling continuous or periodic signal transmission while passive tags rely on external sources for power.
• Anchors/Readers: Fixed in strategic locations throughout the area, these devices capture signals emitted by the tags. These signals are used to calculate the position of the tags. Anchors are crucial for receiving the necessary data to determine the location of the tags.
• Location Engine: The location engine is the software component that processes data from the tags and anchors. It uses algorithms to calculate and determine the exact position of the tracked items.

To dive deeper into the specific elements that make up an RTLS, read the article on RTLS Components.

The Location Calculation Process

• Signal Transmission: Anchors emit radio signals at regular intervals.
• Signal Reception: Tags receive these signals, measuring their strength and timing.
• Data Transmission: The tags send data, including signal strength and time stamps, to the location engine.
• Location Calculation: Using methods like triangulation or multilateration, the location engine calculates the position of each tag based on the received signals.
• Data Processing: The calculated locations are processed and displayed on a map or dashboard, providing a real-time overview of all tracked items.

Types of RTLS Technologies

To enable indoor positioning, Real-Time Location Systems (RTLS) primarily utilize radio frequency (RF) technologies such as Ultra-Wideband (UWB), Bluetooth, Wi-Fi, and RFID. These technologies facilitate wireless communication between a network of transmitting, receiving, or dual-purpose transceiving devices, which are crucial for determining the location of tracked objects.

The effectiveness of an RTLS system largely depends on the technology it uses, including:

• Ultra-Wideband (UWB): Known for high precision and reliability, UWB is ideal for applications requiring accurate location data.
• Bluetooth Low Energy (BLE): Offers a good balance between accuracy and power efficiency, making it suitable for various applications.
• Wi-Fi: Commonly used for data communication, Wi-Fi can also support RTLS, particularly in areas with established Wi-Fi infrastructure.
• Radio Frequency Identification (RFID): Often used for item-level tracking, RFID can be integrated into RTLS systems for comprehensive asset management.

Want to know more about these technologies, check out our article on RTLS technologies.

RTLS System Operations

RTLS systems operate using a combination of hardware and software:

• Tags and Transmitters: These devices emit signals detected by anchors or readers. Some systems use fixed transmitting devices, like Bluetooth beacons, to broadcast signals.
• Anchors and Readers: Placed throughout the area, these devices capture the transmitted signals and may also collect additional data such as temperature or battery status.
• Location Engine: The data collected is sent to a central processing unit or server, where the location engine processes it using algorithms to determine the position of each tag.

How It Works

1. Transmitting Devices: The process begins with RF tracking tags or smartphones, which serve as transmitting devices. These devices emit data-encoded RF signals, often referred to as location “blinks,” at regular intervals.
2. Receiving Devices (Anchors/Readers): Anchors or readers, which are strategically placed in fixed positions within the coverage area, receive these signals. These devices are typically mounted on walls or other structures to maintain optimal communication range. They not only capture the location data but, in certain applications, can also collect additional IoT data such as temperature or battery status.
3. Data Processing: The received data is forwarded to location engine software, which processes the information to calculate the precise position of the transmitting devices. Different RTLS technologies may use various techniques for this purpose. For example, some systems use distance-based calculations like Time Difference of Arrival (TDoA), which often provides more accurate results than methods like Received Signal Strength Indicator (RSSI).
4. Visualization and Integration: The calculated location data can then be visualized on digital maps or integrated into various enterprise applications, enabling a wide range of location-aware use cases. This includes real-time tracking of assets, personnel, and equipment.

In some RTLS implementations, fixed transmitting devices like Bluetooth beacons are used. These beacons broadcast signals at consistent intervals, which can be detected by BLE-enabled devices such as smartphones. The collected location data is then transmitted to an indoor positioning application to determine the device’s position and potentially trigger specific actions.

Beyond tracking, RTLS components can also support ranging applications. This involves measuring the relative distance between two devices, such as transceiver tags, facilitating proximity-based applications and enhancing safety and operational efficiency.