RTLS technology comparison
Comparison of RTLS technology and its pros and cons: There are three main affordable RTLS asset tracking (Real Time Location System) technologies: WiFi, Bluetooth Mesh Low Energy (BLE), Bluetooth AoA and Ultra-Wideband (UWB).
WiFi:
Pros:
- Wide range: WiFi signals can travel through walls, making them suitable for large indoor and outdoor spaces.
- Existing infrastructure: Many buildings already have WiFi, so deploying WiFi RTLS can be relatively easy
- Mature technology: WiFi is a well-established technology with a wide range of available tags.
Cons:
- Lower accuracy: WiFi RTLS has an accuracy of 1-5 meters, which may not be sufficient for some applications.
- Multipath interference: WiFi signals can bounce off walls and other objects, which can lead to inaccurate location readings, especially when there are partitions in the warehouse.
- Higher power consumption: WiFi tags can drain batteries more quickly than BLE or UWB tags; hence, there is a cost associated with maintaining them.
Bluetooth Low Energy (BLE) – Bluetooth Mesh
Pros:
- Lower power consumption: BLE tags can last for months or even years on a single battery.
- Good for indoors: BLE signals have a shorter range than WiFi, but they penetrate walls and obstacles better, making them a good choice for indoor applications.
- Lower cost: BLE tags and readers are typically less expensive than WiFi or UWB compared to RTLS technology
Cons:
- Shorter range: BLE typically has a range of 10-30 meters, which may not be sufficient for some applications; however, mesh networks such as Bluetooth Mesh enable long-range tracking
- Limited scalability: BLE can struggle to track a large number of tags in a dense environment. A mesh network helps in scalability to support a large number of tags.
- Lower accuracy: The BLE RTLS asset tracking system has an accuracy of 3-5 meters, which may not be sufficient for some applications.
Ultra-Wideband (UWB)
Pros:
- High accuracy: UWB can achieve accuracy down to centimetres, making it ideal for applications that require precise location tracking.
- Good for multipath environments: UWB is less susceptible to multipath interference than WiFi or BLE.
- Secure: UWB signals are difficult to jam or spoof, making them a good choice for security applications.
Cons:
- Higher cost: UWB tags and readers are the most expensive of the three technologies.
- Shorter range: UWB typically has a range of 10-50 meters, which may not be sufficient for some applications.
- Limited availability: UWB is a relatively new technology, and there are fewer tags and readers available than WiFi or BLE.
Bluetooth AoA – Angle of Arrival
Bluetooth Angle of Arrival (AoA) is a modern technology for pinpointing indoor locations with remarkable accuracy. Rather than simply measuring signal strength, it operates by calculating the precise direction from which a Bluetooth signal originates. This capability enables AoA to achieve centimetre-level accuracy, a significant improvement over traditional methods like Bluetooth RSSI (Received Signal Strength Indicator), which are only suitable for detecting proximity. This high degree of precision makes AoA a powerful tool for applications such as asset tracking, indoor navigation, and various other location-based services.
How Bluetooth AoA Functions
The Bluetooth AoA system operates using two primary components: a transmitting device (the tag) and a receiving device (the locator).
The Transmitting Device (Tag): This is typically a straightforward Bluetooth unit that sends out special data packets from a single antenna.
The Receiving Device (Locator): A more advanced piece of equipment, the locator features a specialised antenna array, which is a collection of several antennas arranged in a particular pattern. The locator continuously analyses the subtle phase difference of the incoming signal as it reaches each of its antennas. This phase variation is directly linked to the angle of the signal’s arrival. By combining the data from multiple locators, a central system can then use triangulation to determine the tag’s exact position.
Wirepas mesh – pros and cons
Wirepas mesh is possibly the most reliable and resilient among low-powered IoT networks suited for indoor positioning in low-latency and low accuracy (5-meter) applications. The easy-to-deploy network, however, has yearly licensing costs for the anchors and needs dedicated cloud hosting for the positioning engine. The device ecosystem is yet to be fully developed, unlike in the case of Bluetooth Mesh.
Ultimately, RTLS technology comparison will depend on your specific needs and budget. If you need high accuracy and security, UWB is the best option. If you need a low-cost solution for indoor tracking, Bluetooth Mesh RTLS infrastructure is a good choice. And if you need to track assets in a large outdoor space, WiFi may be the best option for indoor positioning systems that are easy to deploy, low on maintenance, portable for demolition sites and remote worker monitoring. Read about Digital Twin