Comparison of Bluetooth LE Locating Methods

There’s research just published on A Comparison Analysis of BLE-Based Algorithms for Localization in Industrial Environments. The research compares trilateration, fingerprinting and a machine-learning based k-nearest neighbors regressor for determining the location from signals from multiple beacons.

Multi-layer perceptron (MLP) schematic model
Error box plots for the three fingerprinting algorithms with different beacon densities. Results for a fingerprint grid with one measurement every 0.5 m.

The results show fingerprinting is better than distance-based schemes in industrial environments due to the presence of large moving metal objects that shadow and reflect wireless signals. The three methods were found to provide similar localisation accuracy. The authors say the machine learning method is best due to less complexity and better adaptability. The machine learning method does not need regular calibration as is the case with fingerprinting.

Read about Determining Location Using Bluetooth Beacons

Low Power Bluetooth Advertising Chip Without SoC

Asahi Kasei Microdevices Corporation has announced the AK1595. As with the previously mentioned AK1594, it works without a System on a Chip and provides Bluetooth transmission using very low power.

Instead of setting the advertising via EEPROM programming like the AK1594, the AK1595 is controlled via UART or I2C making it suitable for variable data transmission scenarios.

We expect the AK1595 will be particularly useful for energy harvested applications.

Sensor Triggered Advertising

Most of our sensor beacons with accelerometers offer motion triggered broadcast. That is, they can be set up to advertise when the beacon is moving. This can be used for motion detection or, in some scenarios, as a mechanism to significantly conserve battery life.

Some beacons such as the Minew range with buttons can be set to only advertise when there’s a double press of the button. This can be used for SOS type scenarios.

The S1 temperature humidity beacons can also be set to advertise when the temperature or humidity goes above or below a value. This is useful for alarm type situations.

S1 Beacon

While triggered broadcast provides for these usecases and extends battery life, it should be remembered that because the beacons are not advertising all the time, there’s no way of knowing their location (in RTLS situations) or indeed if the beacon is working (e.g. the battery might be flat). Beacons such as the INGICS range advertise all the time and send different advertising when a button is pressed or the temperature/humidity changes. This allows for ‘I am still here’ functionality at the expense of shorter battery life.

Bluetooth in Aviation

Bluetooth beacons are increasingly being used in the aviation industry to track pallets, unit load devices (ULDs) and audit temperature, humidity and shock levels.

Cargo Airports & Airline Service magazine has an article on the Bluetooth Revolution where it mentions ULD provider Unilode’s use of Bluetooth tags. Unilode is equipping its 125,000 ULDs with Bluetooth readers. This will take over two years but 80% should be fitted out within 18 months.

The most significant development recently in ULDs is the development of Bluetooth Low Energy tracking devices.

The article mentions how Unilode has been exploring the use of RFID over last 25-30 years. It says Bluetooth provides the solution to RFIDs limits of range, infrastructure cost and interference with aircraft systems. Bluetooth additionally allows monitoring of ambient shipment conditions, temperature sensitive cargo and shock sensitive cargo.

The key benefit of Bluetooth is knowing where units are, all the time, rather than relying on scanned updates. It provides for better utilisation of assets. This makes transport of freight easier, smoother and more efficient.

Real-time monitoring of assets allows the client to immediately know when assets are behind schedule, being routed inappropriately, or in poor conditions.

Bluetooth not only provides a scaleable and affordable way of tracking pallets and unit load devices but can also provide for tracking the status of smaller critical packages such as pharma and and cosmetics goods.

Here at BeaconZone, we have seen beacons used more for airline temperature sensing rather than tracking. For example, iB003N-SHT beacons are used by Qatar Airways to monitor the temperature of pre-flight cargo holding areas.

New Bluetooth Range Extender

Nordic Semiconductor, the manufacturer of the System on a Chip (SoC) inside most beacons, has announced a new Bluetooth Range Extender the nRF21540.

It’s an electronic component to be used at the SoC output to amplify the signal prior to being sent to the antenna. We expect this to be included in some future long range beacon designs. However, note that it uses more current (115 mA at +20 dBm) so is less suitable for use in coin-cell based battery powered designs.

Our ultra long range beacons already use RF amplifiers but from different component manufacturers. For example the iB003N-PA uses a RFAXIS X2401C chip to achieve up to 300m range. The FSC-BP109 also uses an output amplifier to reach up to 1000m on Android and 4000m on iOS but this beacon requires USB power.

How to Open Minew S1 Case

We have recently started stocking the Minew S1. Minew have a video showing how to change the battery:

If you are changing the batteries we recommend you use Lithium batteries, such as Energizer Lithium, rather than alkaline batteries. This gives a longer battery life, flatter decrease in voltage over time and better resilience under lower temperatures.

RTLS in Healthcare

There’s a new Mr Beacon video interview with HT Snowday, VP of Innovation and Technology Development at Midmark RTLS. Midmark and HT are formerly of Versus Technology who were acquired by Midmark in Aug 2018.

Midmark RTLS uses a combination of infra-red, 433Mhhz RF, WiFi and Bluetooth to provide tracking of healthcare assets, care givers and patients. It allows medical equipment to be located quickly, key things such as IV pumps to be effectively distributed (par levelling) and the location of care staff and patients to be controlled and monitored. The Bluetooth part of Midmark RTLS is used more for wayfinding using powered, static beacons to mark locations. Systems also allow for health workflow processes including self-rooming to reduce waiting and queuing for care.

Healthcare is increasingly being provided at outpatient rather than inpatient treatment. This is leading to more clinics and treatments centres and the need for technical sophistication to efficiently process patients.

No mention was given to other crucial healthcare usecases we have come across at BeaconZone such as tracking (and temperature) of valuable medicines, tracking porters, wheelchairs and wayfinding from the hospital limits to reception areas.

Read about Beacons For Life Sciences

Physical Web App for Android

There’s a new Physical Web app for Android by the Physical Web Association. The app detects beacons advertising Eddystone URL.

The new app and the Physical Web Association take up the space left by Google abandoning the Physical Web. The association’s apps are unbranded so can be used by anyone to provide for information triggered by beacons.

The Physical Web Association aims to provide the universal apps, metadata services and support. Mr Beacon has a new interview with Agustin Musi and James Grant, founders of the Physical Web Association. It explains how the Association hopes to work with manufacturers to simplify the beacon setup experience. It also mentions opportunities to use Eddystone URLs to lead to progressive web apps to provide device control using web Bluetooth APIs. This was one of the original premises of Google’s ambitions for the physical web.

Unlike Google’s implementation, the Physical Web Association hopes to create a publisher-driven categorisation/ranking system and end user app settings to limit and filter when notifications are shown when beacons are detected in background.

View Eddystone beacons