Real-Time Location System (RTLS) tags are fundamental components of modern tracking solutions, enabling the precise location of assets and personnel in real-time. These tags serve as the backbone of RTLS, playing a critical role in streamlining operations, improving efficiency, and ensuring safety across industries.
What are RTLS Tags ?
RTLS (Real-Time Locating System) tags are pieces of hardware that send location signals or pings to nearby RTLS anchors to calculate their position. These tags vary in complexity, shape and size depending on the use case, industry, and supplier.
Most RTLS tags usually have 4 basic components:
- Power Source: Such as a battery, offering extended lifespans.
- Processing unit: A chip that processes data.
- Tiny Radio Antenna: Facilitates communication with the RTLS system.
- Sensors: like a barometer, carbon dioxide, or thermometer.
Types of RTLS Tags
Active RTLS Tags
Continuously transmit signals, powered by an internal battery.
- Accuracy: Medium to high, depending on the underlying technology (e.g., UWB, BLE).
- Applications/Use Cases: Ideal for environments requiring constant updates, such as tracking high-value assets or personnel in motion.
- Range: Typically ranges from 30 meters (BLE) to 100+ meters (Wi-Fi-based tags).
Passive RTLS Tags
Powered by external sources (e.g., an RFID reader’s signal), these tags do not have an internal power source, making them cost-effective and lightweight.
- Accuracy: Low to medium; varies depending on factors like the reader’s power, placement and environmental factors like interference.
- Applications/Use Cases: Commonly used for cost-sensitive tasks such as inventory management in logistics, retail, food and beverage, and healthcare industries. Their affordability makes them ideal for tracking high volumes of items.
- Range: Typically limited to a few meters; can extend up to 10 meters with high-power RFID readers. UHF passive tags often provide the longest range within this category.
Technologies Behind RTLS Tags
Chirp Spread Spectrum (CSS):
Chirp Spread Spectrum (CSS) is a wireless communication technology that uses frequency-modulated chirp signals to transmit data. It operates by spreading the signal across a wide frequency range, making it robust against interference and capable of maintaining reliable performance over long distances.
- Performance & Accuracy:Provides moderate accuracy, suitable for scenarios where sub-meter precision is acceptable.
- Cost: Cost-effective for large-scale applications, though it may require specialized infrastructure.
- Applications/Use Cases: Ideal for campus-wide tracking, agriculture, and large industrial sites where a longer range is critical.
- Range: Long-range; can exceed several hundred meters depending on the setup and environmental factors.
RFID (Radio-Frequency Identification):
Uses electromagnetic fields to identify and track tags.
- Performance: They are highly reliable in controlled environments and excel in inventory tracking tasks.
- Cost: Passive RFID tags are inexpensive, making them ideal for large-scale deployments. Active RFID tags, which provide extended functionality, are more costly.
- Suitability: Common in warehouses and retail for inventory management, asset tracking, and access control. It is well-suited for environments where low-cost, low-maintenance solutions are required.
- Range: Low-frequency (LF) RFID: Up to 1 meter. High-frequency (HF) RFID: Up to 1 meter. Ultra High-frequency (UHF) RFID: 1 meter to 12 meters, and some systems can extend beyond 30 meters in optimal conditions.
Bluetooth Low Energy (BLE):
- Performance: They are suitable for tracking personnel and assets where high accuracy is not a critical requirement.
- Cost: BLE tags are cost-effective, with an excellent balance between functionality and affordability. They are relatively cheap to deploy due to the widespread availability of Bluetooth-enabled devices.
- Suitability: Ideal for moderate accuracy use cases such as employee tracking, asset management, and indoor navigation in healthcare, office spaces, and retail environments.
- Range: BLE typically offers a range of 10 meters to 100 meters in open spaces. However, performance can degrade in obstructed or interference-heavy environments.
Ultra-Wideband (UWB):
- Performance: UWB offers unparalleled accuracy, capable of centimeter-level precision. Its performance excels in real-time tracking applications requiring high precision in challenging environments.
- Cost: UWB tags and infrastructure are more expensive compared to RFID and BLE but provide superior value for industries needing high accuracy.
- Suitability: Best for demanding environments like heavy manufacturing (automotive, metals), medical device manufacturing, and discrete manufacturing, where precision and reliability are critical.
Range: Short-range but highly precise, typically up to 40-50 meters.
Wi-Fi-Based Tags:
- Performance: Wi-Fi tags leverage existing Wi-Fi networks, making them a cost-effective solution. However, they offer lower accuracy compared to BLE and UWB.
- Cost: Utilizing existing infrastructure reduces deployment costs, making Wi-Fi tags a budget-friendly option.
- Suitability: Widely used in retail, entertainment, and healthcare for applications where moderate accuracy is acceptable and leveraging existing infrastructure is a priority.
- Range: Wi-Fi tags usually have a range of 30 meters to 100 meters in open spaces.
Key Features of RTLS Tags
Battery Life:
Varies widely, with some active tags lasting up to seven years depending on usage and refresh rate.
Some tags are being developed to have multiple AAA or AA batteries to achieve even longer lifespans.
Batteries are always something to take into consideration, and most platforms have an adequate battery monitoring and management platform.
It is important to note that additional sensors such as thermometer, carbon dioxide, and barometric can dramatically impact the battery.
Signal Range:
Dependent on technology; UWB offers short but precise ranges up to 40-50 meters, while Wi-Fi can cover large areas up to hundreds of meters.
These differences in distances however usually translate to a difference in accuracy. For instance, UWB can achieve more than 40-50 meters in highly metallic environments and, but the accuracy will likely drop.
BLE and Wi-Fi at these ranges will be much less accurate than UWB but will have certain cost and potential existing infrastructure benefits. However, it is important to note that BLE and Wi-Fi often struggle in demanding industrial environments and should be used if cost and accuracy requirements are low.
Sensor Portfolio:
More and more RTLS tags are being integrated with a variety of sensors, such has temperature, pressure, and air composition.
Although there are a large variety of sensors that can be integrated into your RTLS tag, please keep in mind its implications on battery life.
The most common sensors into RTLS tags tend to be shock sensors for forklifts. Additionally, temperature sensors have been increasingly adopted in the food and beverage, and logistics industry.
Durability:
Designed to withstand harsh conditions such as extreme temperatures or exposure to chemicals. Many RTLS providers are flexible on the type of form factors they can supply.
It is true that it is the most affordable to simply order the OEM types, but for certain application and use cases, like in the medical and metals manufacturing industries, custom tags with ugged casings to protect against extreme temperatures, moisture, and chemicals.
Data Transmission Rates:
Configurable “blink” rates, or location pings, allow tags to send updates at specified intervals, balancing power consumption and real-time needs.
Some RTLS providers only manufacturer one time of anchor which is often powered by POE and some manufacture anchors that are battery powered.
Battery powered anchors, although eliminate cabling and installation costs dramatically, are generally confined to data transmission rate within 0.3 to 1 HZ, or 3 to 10 second blink rates.
Applications of RTLS Tags
Healthcare:
- Monitor medical equipment like beds and wheelchairs. Typically used for tracking patient flow in and out of rooms and faciltiies.
- Enhance hospital asset utilization like infusion pumps and gain insights to the usage of expensive assets across the facility.
- Monitor patient-clinician interaction time for counseling or care giving sessions.
- Duress signals are given to patients or clinicians when there is situation that needs attention by other staff members.
Manufacturing:
- Real-Time monitoring of logistic vehicles like forklifts or tuggers. Understanding loaded vs unloaded time (Value Added Miles or Nonvalue Added Miles) , whereabouts, and fuel consumption of intralogistics fleets can deliver immense cost savings and operational efficiency.
- Continuous monitoring of raw materials, and WIP from receiving to production and measuring the time it takes to complete production or manufacturing processes give leaders further insight how to improve their operations.
- Real-time monitoring of production systems, equipment and tools to understand availability based on the location of certain assets at certain times, and predefined thresholds to improve material flow and planning.
- Inventory tracking and monitoring is also a common use case of RTLS. In some cases, it helps eliminate plant shutdowns for audits, and helps automate inventory reporting benefiting teams from warehousing, finance, and logistics.
Warehousing and Logistics:
- Enable precise inventory tracking, improve inventory accuracy, and reduce search time in logistics operations.
- Integrated pick lists between a company’s ERP or WMS to improve picking productivity and inventory management
- Fleet OEE, value added miles vs nonvalue added miles, fuel consumption, along with heatmaps and spaghetti diagrams for space and warehouse optimization and utilization.
- Route Optimization is increasingly being placed on companies’ digitization strategies. Route optimization for forklifts or pickers can vary, but it generally involves integrating WMS or ERP data with RTLS and machine learning to guide the nearest worker or vehicle to the pickup or drop-off spot.
Employee Safety:
- Ensure personnel safety in hazardous environments through location-based alerts and monitoring.
- Lone worker safety alerting when workers go to hazardous areas of the plant, often alone such as furnace rooms or freezers. Thresholds can be set to give alerts after a specific time if an employee has overstayed the maximum time spent in a particular zone
- Vehicle-Employee alerts, slowdowns or even stops when proximity thresholds are surpassed.
Forklift Safety:
- More forklifts are being integrated with RTLS tags to ensure safety and compliance protocols in demanding and sometimes hazardous environments such as manufacturing.
- Forklift-Forklift alerting and safety lights or buzzers are being implementing using RTLS data.
- Forklift slowdowns can be achieved by using relays and canBUS integration. Typically, these are used for warehouse aisles and tight corners with low visibility to other vehicle or pedestrian traffic.
Benefits of Implementing RTLS Tags
- Operational Efficiency:
Real-time data enables optimized workflows and asset management. Augmenting location with other metrics on machine, tools, or intralogistic vehicles can give you an additional layer of insight into how efficient your operations are.
- Asset Utilization:
Reduced losses and improved deployment of resources. By minimizing asset loss and downtime, organizations can improve operational efficiency, reduce overhead costs, and maximize the ROI of their equipment. This capability is particularly valuable in environments like heavy and discrete manufacturing, logistics, and healthcare, where efficient resource allocation directly impacts productivity and service delivery.
- Safety and Compliance:
Enhanced visibility of personnel and equipment contributes to a safer work environment. RTLS supports a wide array compliance standards and industry regulations by documenting asset usage, tracking access to restricted areas, and ensuring adherence to safety protocols. In industries such as mining, oil and gas, or construction, RTLS contributes to a safer, more transparent work environment. Additionally, using the traceability that RTLS provides gives leaders an additional trove of data to use when compliance is critical.
- Data-driven decision-making capabilities: By integrating RTLS data with analytics platforms, businesses can use raw location data to gain real-time visibility into asset utilization, workflow bottlenecks, and operational inefficiencies. This level of insight empowers predictive maintenance, resource optimization, and process improvements, ensuring informed decisions that enhance productivity and reduce costs.
Challenges and Considerations
- Setup Costs:
Initial investments in hardware, software, and integration can be significant. Depending on the environment and use case, it is important to consider the cost of implementing the hardware itself, such as cabling, and in some cases, calibration. Before implementation, expect a site survey for proper anchor placement.
- Signal Interference:
Environmental factors, such as metal surfaces or thick walls, may disrupt signals.
- Data Privacy:
Protecting sensitive data and ensuring compliance with privacy regulations is critical.
Future Trends in RTLS Tag Technology
- Battery Advancements:
Innovations are extending the lifespan of active tags, reducing maintenance needs. There are some tags on the market that can achieve up to 7 years of battery life.
- IoT Integration:
Combining RTLS tags with IoT devices enhances data analytics and predictive maintenance. From MES, WMS, or ERP integrations, the possibilities of integration for further intelligence and applications expand.
- Miniaturization and Cost Reduction:
Smaller, more affordable tags make RTLS accessible to more businesses and industries.
Selecting the Right RTLS Tag for Your Needs
- Application Requirements:
Define the specific use case and tracking objectives. The use case often determines the viability of the project itself. Consider the ROI and business case that can support such an investment.
- Environmental Factors:
Consider the operating environment and potential obstacles to signal transmission.
- Expert Consultation:
Engage RTLS solution providers to identify tailored recommendations.
Conclusion
RTLS tags are transforming industries by enabling real-time visibility, improving operational efficiency, productivity, and ensuring safety. As technology evolves, RTLS tags will continue to offer unprecedented opportunities for businesses to innovate and optimize their existing operations.
