- Lower Power and Greater Location Accuracy
- Smaller Antenna Array for Gateways
- Healthcare Solutions Track Assets, Patient Safety
Jul 22, 2022Silicon Labs has released the 5.3 version of its Bluetooth Location Services solution, which employs transmission angle of arrival (AoA) and angle of departure (AoD) to pinpoint the location and direction of a Bluetooth Low Energy (BLE) device. This is the latest version of the company's family of solutions designed to identify where assets, individuals or high-value goods are located using BLE tags and fixed gateways. The company's BG22 Bluetooth system-on-chip (SoC) is now being commercially released with twice the location accuracy of its earlier version, plus a smaller antenna array for more compact gateway devices and tags.
Borda Technology, one of the initial solution providers to adopt this technology into its own platform, is the first to announce a partnership with Silicon Labs. This will enable hospitals around the world to track the locations of healthcare assets and patients in real time, according to Mikko Savolainen, Silicon Labs' marketing director for Bluetooth. Borda focuses on wireless Internet of Things (IoT) products for the healthcare market. Its technology enables hospitals to achieve greater efficiency and improve health outcomes for patients, by managing the location and status of facilities' equipment and assets, as well as offering patient-management and patient-flow solutions.
The BG22 5.3 SoC comes with Silicon Labs software designed for tracking assets, as well as indoor navigation solutions to provide sub-meter accuracy. According to the company, the solution is aimed at making development faster, with more accurate BLE location accuracy, for businesses that build IoT solutions. The integrated circuits company is located in Austin, Texas. Since its launch in 1996, it has offered RF synthesizers for cell phones, FM radio tuner products for handsets, and micro-controller units. In recent years, the firm has been providing BLE solutions, and it also produces software stacks, including firmware libraries and its free software-development platform known as Simplicity Studio.
Lower Power and Greater Location Accuracy
The BG22 BLE chips can be built into both gateways (locators) and tags. They transmit at low power—3.4mA TX at 0dBm—and leverage a 76.8 MHz Arm Cortex-M33 core. The SoCs' power efficiency, Savolainen says, means devices built using the system could run on a coin-cell battery for up to ten years. Companies in the industrial and commercial sectors have been seeking a real-time location solution that can provide location data with a low-cost infrastructure, he adds, whether within a room or to centimeter accuracy.
Mikko Savolainen
When it comes to hospitals, Savolainen says, solution providers have indicated that, on average, nurses can spend seven to 20 percent of each shift looking for equipment, ranging from hospital beds to respirators that patients require for treatment and recovery. A variety of automatic identification solutions are available. One example is ultra-wideband (UWB) technology, which is highly precise but consumes more power than BLE-based technology. Some hospitals use their existing Wi-Fi networks for asset tracking, though there are limits to this technology as well, both in terms of power consumption and location accuracy.
"It might be hard to reach room-level accuracy with Wi-Fi," Savolainen notes, so a Wi-Fi tag on a piece of medical equipment might not be located specific to a room. The power consumption could be as much as 10 times that of a BLE tag, he adds, so larger batteries would be required, or there would need to be more frequent battery replacements. Coin-cell batteries would be insufficient in most cases.
The benefit of passive UHF RFID, the company explains, is the significantly lower cost of the battery-free tags, which are typically priced at less than 10 cents apiece, whereas BLE tags would cost more than a dollar. However, RFID would not provide real-time location. "To do real-time inventory with RFID, [hospitals] need to send an employee with an RFID scanner to scan everything," Savolainen states. "That can be a time-consuming and labor-intensive operation."
Silicon labs' solution is aimed at low-cost, real-time location. While healthcare is proving to be one of the early adoption markets for this technology to generate indoor positioning and indoor asset-tracking solutions, Savolainen says, the system could also be used in retail, logistics and other markets.
Smaller Antenna Array for Gateways
The solution offers a new antenna array designed for use in gateways that can make the entire device smaller and thus lower in cost than predecessor technologies, Savolainen reports, while providing approximately twice the accuracy of previous versions. "We have provided performance improvements and optimizations in size and cost," he states.
The latest antenna array measures 150 millimeters by 150 millimeters (5.9 inches by 5.9 inches), which is 15 percent smaller than the previous version. With this reduced size, Savolainen explains, the technology could be small enough to be discretely mounted or installed around a facility. The chip can also be embedded in the Bluetooth chips that transmit data to the gateways.
According to Silicon Labs, the technology comes with tools to help developers more quickly build an effective solution according to the application. Its Real Time Location (RTL) Library computes the positions of tags by capturing input from all gateways within a deployment, then calculating the position of each tag transmitting to those gateways. The RTL Library can operate in the access point or gateway if the solution includes a high-performance processor, or it can operate in the cloud. "We support both options," Savolainen says.
Simplicity Studio is an integrated set of direction-finding tools to speed up development and provide debugging, the company reports. Location accuracy or direction detection (understanding the direction in which a tagged item is moving, such as into or out of a room) will vary depending on the needs of a particular application and user. Some businesses may only require the locations of items within a room, the company's partners have indicated. In such a case, a single gateway could provide data indicating in which room an item is located, as well as potentially what part of that room, within a handful of meters, based on AoA.
If, however, a user needed to know very specifically where an item was located, such as on a given shelf or at a particular bed in a specific hospital room, then multiple gateways would be required to provide a trilateration solution. The device comes with an optional accelerometer to detect movement, as well as a barometer to detect air pressure, enabling users to determine height. The accelerometer can prompt a tag to only transmit when it senses movement, thereby reducing power consumption.
Healthcare Solutions Track Assets, Patient Safety
Borda is offering solutions that leverage the technology for asset tracking, as well as for managing asset maintenance, by identifying where a piece of equipment is and has been (such as in a cleaning room for disinfection) before being used on a patient. The technology can also capture patient-flow data by tracking where patients wearing wristband are located, and it can monitor infant safety by tracking when babies leave a nursery and with whom.
Beyond healthcare, Silicon Labs notes, numerous other applications are being considered as well. Shared and rented bicycles offer another use case, for instance. Such bikes, including those that help city inhabitants commute around their neighborhoods, can be tracked via BLE tags. Cities or agencies must often track thousands of shared cycles to ensure every battery is recharged. With the BLE technology, gateways around a city could identify the specific points at which bikes have been left after use.
What's more, the system is designed to prevent interference and ensure accurate reads in crowded environments. For instance, the SoC employs asynchronous continued tone extension (CTE) broadcasts to transmit a signal from the tag to the locator or gateway. Asynchronous broadcast eliminates the need for synchronized transmission timings between a device and a locator, the company explains, thereby enabling the locators to track a large number of assets simultaneously. Additionally, its broad-spectrum CTE broadcast across all 37 channels helps the solution to reduce interference by moving the CTE transmissions from advertisement to data channels.
"These new features enhance Silicon Labs' Bluetooth software portfolio, one of the most comprehensive set of solutions available for accelerating development of direction-finding applications," Savolainen states. He predicts that developers and designers will build a wide range of IoT location service applications.
Key Takeaways:
- The 5.3 version of Silicon Labs' SoC and related technology is designed to make very granular location data possible, with a 6-inch gateway antenna dimension.
- Borda is among the first solution providers to build solutions with the technology, enabling hospitals to track the locations of their assets within rooms, or even within less than a meter-wide area, depending on the deployment.
