iBeacon, Eddystone, Bluetooth, IoT sensor beacons, apps, platforms
One mistake some projects make is to choose physically attractive beacons. Some manufacturers make their beacons look attractive to try to secure more sales. However, in use in some scenarios, the beacons can become attractive to thieves or children and become lost.
We once had a train transport customer ask “What’s your most unattractive beacon ?”
Brightly coloured beacons can invite thieves
Small black boxes remain anonymous
There’s new research by ITMO University, Russia on the Implementation of Indoor Positioning Methods: Virtual Hospital Case. The paper describes how positioning can be used to discover typical pathways, queues and bottlenecks in healthcare scenarios. The researchers implemented and compared two ways to mitigate noise in Bluetooth beacon RSSI data.
The probabilistic and neural network methods both use past recorded data to compare with new data. This is known as fingerprinting. The neural network method is less complex when there’s need to scale to locating many objects. The researchers tested the methods at the outpatient department of the cardio medical unit of Almazov National Medical Research Centre.
Comparison of the methods showed they give approximately the same error of between 0.96m and 2.11m. However, the neural network-based approach significantly increased performance.
There are many scenarios that require accurate tracking of assets and people. Logistics can ensure efficient use of equipment and improve workflows. Manufacturing can locate valuable plant tools, parts and sub-assemblies, improve safety and enable efficient asset allocation. Healthcare can track high value equipment, monitor the location of medicines, save time searching for equipment and monitor vulnerable patients. Facilities can track valuable assets, monitor lone workers, check occupancy levels and automatically locate people or students for safety and evacuation.
New AoA direction finding brings sub-metre tracking to Bluetooth where the main alternative was previously expensive, proprietary ultra-wide band (UWB). AoA direction finding uses receivers, called locators, that have multiple antenna. The differences in phase of the signal arriving from a beacon to each antenna are used to determine the direction.
One locator can be used to determine the location or multiple locators can be used to triangulate a more accurate beacon position.
You can’t use just any beacon. It needs to send a Constant Tone Extension (CTE) for a long enough time to enable the receiver to switch between all the antennas.
Martin Woolley’s excellent Bluetooth Direction Finding Technical Overview provides a deeper explanation of the theory.
The calculation of data from the antennas to angles is called radiogoniometry. This can be performed by the the same microcontroller hardware that’s receiving the radio data, by a gateway or by a separate location engine on a local server or in the cloud. The problem with using the same microcontroller is that it is slow and doesn’t scale well to larger numbers of beacons. Also, it doesn’t know about other locators and so can’t do triangulation when multiple locators see a beacon.
There are many ways to implement the location engine using different radiogoniometry algorithms of different accuracy and computational complexity. The location engine should also filter the incoming data to mitigate the affects of multi-path reception, polarization, signal spread delays, jitter, and noise. It also needs to be performant, ideally using compiled rather than interpreted code, to support the maximum throughput and hence the maximum number of beacons. It should also also provide a streaming rather than polling API to pass data onto system and applications such as real time locating systems (RTLS).
Read about PrecisionRTLS™
The new wearable, rechargeable Minew B10 beacon is now available.
This beacon works like a standard Minew beacon advertising up to 6 channels that can be iBeacon, Eddystone UID, Eddystone URL, Eddystone TLM, acceleration and device info. The button can be set to specific advertising for one, two of three presses. There’s a flashing led and vibration when pressed. There’s also a 6-axis accelerometer that can be used to analyse movement or for motion triggered broadcast.
A full charge lasts up 60 days per charge depending on settings.
We have the new Minew P1 Plus in stock. It’s a sensor beacon designed for rough environments and is IP68 waterproof, IK09 shockproof and has a wider than normal temperature rating due to use of the included industrial ER14250H lithium battery.
This beacon has temperature and accelerometer sensors. It’s turned on and off via a magnetic switch. As with other Minew beacons it advertises up to 6 channels that can be iBeacon, Eddystone UID, Eddystone URL, Eddystone TLM and device info.
Small beacons are sometimes needed so that they remain unobtrusive or need to be embedded into larger devices. The smallest, cased, beacons we supply are:
The compromise with small beacons is that they have CR2032 batteries that don’t last as long as larger battery beacons. If the beacons won’t be moving and you have access to USB power, consider using USB beacons that are also small.
Almost all beacons are slight derivations of a few standard circuit designs and firmware provided by Texas Instruments, Dialog and Nordic who produce the System On a Chip (SoC) inside beacons. The SoCs are general purpose devices that can do a lot more than just advertise as beacons but the beacon manufacturers only provide fixed firmware that performs just this one function, occasionally with additional sensing.
The use of firmware-based SoCs for beacons means there’s a lot of hardware and software (SDKs) that goes into creating a beacon. Much of this isn’t needed if the chip is designed for the single purpose of being a beacon. We previously mentioned the AK1594 but have yet to see any designs making use of this device.
The InPlay NanoBeacon IN100 is a newer device that has recently received Bluetooth 5.3 certification. It’s small (DFN8 is 2.5 x 2.5mm), inexpensive (designs using it are expected to be <$1) and no firmware or SDK is required.
The IN100 uses only 650nA when used with 1 minute advertising intervals that means it will last a very long time under battery power. The range can be up to several hundred meters. It’s configured using a programmer board connected by USB. A smartphone app is used for configuration. InPlay have a video demonstrating configuration:
We expect this SoC will end up being embedded in products rather than being used stand-alone in beacons because beacon manufacturers are already heavily invested into firmware-based beacons.
We often get asked if it’s possible to track smartphones using Bluetooth. For example, a retailer might want to know how long someone stays in their store and whether they visit again.
While iOS devices advertise Bluetooth continuity messages it’s not possible to track iOS devices using their Bluetooth MAC address because the address changes over time in order to defeat such tracking. However, as previously mentioned, Bluetooth MAC randomisation can be defeated. Android devices don’t usually advertise but some do if Covid tracking is on.
There’s a new paper by researchers at UC San Diego on Evaluating Physical-Layer BLE Location Tracking Attacks on Mobile Devices (PDF). It looks into Bluetooth physical-layer patterns to track a variety of device types.
A tool has been created to automate discovery of imperfections in signal modulation.
These imperfections are caused by manufacturing variations in the transmitter hardware.
Some, but not all, devices have unique fingerprints and can be tracked.
The MDPI has a special issue of Sensors Journal with a collection of papers related to Bluetooth LE.
BLE applications can be found in a wide range of domains, e.g., smart home, smart cities, smart health, smart agriculture, or Industry 4.0. BLE is enabling the interaction between humans and smart objects, as well as between smart objects themselves. BLE has also been leveraged for innovative location-based applications, opportunistic data collection and crowd-sensing.
All the papers are available free of charge under open access:
Detecting Proximity with Bluetooth Low Energy Beacons for Cultural Heritage
Optimizing the Bluetooth Low Energy Service Discovery Process
Empirical Study of a Room-Level Localization System Based on Bluetooth Low Energy Beacons
Obstruction-Aware Signal-Loss-Tolerant Indoor Positioning Using Bluetooth Low Energy
Efficient Communication Scheme for Bluetooth Low Energy in Large Scale Applications
Experimental Evaluation of 6BLEMesh: IPv6-Based BLE Mesh Networks
Energy Modeling of Neighbor Discovery in Bluetooth Low Energy Networks
Bluetooth 5.1: An Analysis of Direction Finding Capability for High-Precision Location Services
Nordic Semiconductor, the manufacturer of the System on a Chip (SoC) in many beacons, has published the latest online issue of Wireless Quarter Magazine. It showcases the many uses of Nordic SoCs.
The latest issue of the magazine highlights the use of the SoC in the following Bluetooth solutions:
It’s mentioned that hospitals are struggling to manage IoT:
13 percent of hospitals have no inventory of their Internet-connected devices or any way of knowing how many connected medical devices are deployed in their facility… costing their facilities between $21.5k and $45.7k an hour
There’s also an article ‘Dog Gone’ showing wearables are rapidly being worn by animals as owners want to ensure their pets fitness, health and security.
The global pet technology market, which accounted for over $5.5 billion in 2020, is set to grow at 22 percent CAGR from 2021 to 2027 when it will be worth over $20 billion
