We have the new Minew i6 ultra thin beacon in stock.
This beacon is very small and measures 3.5mm x 36.5mm x 23.5mm. It advertises up to 6 channels that can be iBeacon, Eddystone UID, Eddystone URL, Eddystone TLM and device info.
Industry 4.0, or the Fourth Industrial Revolution, is the integration of digital technologies into the manufacturing process to create smart factories. These technologies include sensing, artificial intelligence, machine learning, the Internet of Things (IoT), big data, cloud computing to create more efficient, flexible and customisable manufacturing processes.
A new study by Institute of Technology and Business in České Budějovice, Czech Republic on Possibilities of Using Bluetooth Low Energy Beacon Technology to Locate Objects Internally: A Case Study describes and tests a system capable of locating objects inside buildings using Bluetooth Low Energy (BLE) beacons. The authors conducted a survey of available devices and proposed a low-cost combination of system elements, configured the system, programmed reading gates and web applications for data flow monitoring and finally tested the system in an industrial setting at a manufacturing company in Czechia.
The testing included scenarios with beacon-equipped metal crates being moved around in three different sections of the industrial hall. The study evaluated the system’s ability to detect the beacons and determine their location.
System architecture
The results showed that in the case of direct visibility, the system was able to determine the distance with an accuracy of 94%. However, the measurements also showed that the signal strength was affected by shielding, resulting in worse measurement results in this case and only able to determine the exact distance only 22% of the time.
Crate with a beacon
During a load test, the system and all its sub-components were subjected to several hours of operation, during which the gateways sent requests and collected data about available beacons, processed the requests and stored them in the database. The web application allowed for real-time monitoring of data flow from the individual gateways and the number of beacons in the individual sections. No problems occurred during testing that would cause the measurements to be interrupted, demonstrating the functionality of all system components. The system was considered adequate for most use cases.
Bluetooth Angle of Arrival (AoA) direction finding, part of the Bluetooth 5.1 specification, improves the accuracy of locating using Bluetooth signals. AoA uses the phase difference of the received signal at multiple antennas in a Bluetooth-enabled device to calculate the angle of the incoming radio signal, which can then be used to pinpoint the direction from which the signal was sent.
IQ data comes into play as part of the signal processing. In radio systems, IQ data represents the peaks and troughs of a waveform. I is for ‘In-phase’ part which can be thought of as a signal’s cos component, while Q is for ‘Quadrature’ which is the sin component. This data is derived from the Radio Frequency (RF) front end of the receiver hardware.
The IQ data is translated into direction for further processing, such as determining signal direction in three-dimensional space. Algorithms such as MUSIC (Multiple Signal Classification), ESPRIT (Estimation of Signal Parameters via Rotational Invariance Techniques) and PDDA (Phase Difference Direction Algorithm) turn the IQ data into a pseudo-spectrum the peaks of which provide the direction.
Radiogoniometry has many complexities such as multipath propagation where a radio signal reaches the receiver by two or more paths due to reflection or diffraction from structures or objects in the environment. This causes multiple peaks in the plot. This is where anti-interference algorithms come into play that can mitigate the effects of signal interference, such as multipath propagation and environmental noise. These algorithms rely on statistical signal processing techniques and adaptive filtering methods to distinguish between the desired signal and interference, thereby enhancing the accuracy of direction finding.
Bluetooth beacons are tiny devices that transmit small amounts of data over short distances using Bluetooth Low Energy (BLE) technology. They can operate with different protocols, like iBeacon (developed by Apple), Eddystone (developed by Google), and various sensor beacon protocols.
Despite the fact that it might seem these beacons can advertising multiple protocols simultaneously, it’s not quite the case. What they actually do is advertise these protocols one after the other in a very rapid sequence. This is due to the way Bluetooth works; it’s not technically possible to transmit multiple signals at the exact same moment. Instead, the beacon switches between the different protocols very quickly, which to a casual observer, or a smartphone, might seem simultaneous.
This rapid succession is made possible by BLE’s advertising mechanism. Beacons, in their idle state, continuously broadcast their identity, and potentially other information, in what’s called ‘advertising packets’. When they’re configured to use multiple protocols, they broadcast an iBeacon packet, then an Eddystone packet, then a sensor beacon packet, and so on in a cycle. This is repeated at a very high frequency, many times per second.
However, while this flexibility is advantageous in certain scenarios where various beacon protocols are required, it’s not always necessary and drains the beacon’s battery more quickly. This is because each advertising event consumes energy, and broadcasting in multiple protocols effectively multiplies the number of these events.
Many beacons are set up to advertise multiple protocols by default. If you don’t need this functionality, you can optimise battery life by disabling unnecessary protocols. This is done using a manufacturer-provided app. The exact process can vary between manufacturers and beacon models, but it generally involves connecting to the beacon, accessing its settings and then deselecting the protocols you don’t need.
While multiple-protocol advertising can be useful in certain situations, it’s often more battery efficient to only use the specific protocols you actually need for your application.
iBeacon, Eddystone and AltBeacon are the three main beacon technologies. All of them use the standard Bluetooth Low Energy (LE) advertising format. Bluetooth LE is designed for short bursts of radio that uses little power and is therefore suitable for battery operation. Each of the advertising variants uses a unique advertising packet format that defines what kind of data the beacon transmits.
iBeacon, launched by Apple in 2013, was the first to adopt this technology and created a new wave in proximity services. It uses a simple advertising format, which consists of a UUID (universally unique identifier), Major, and Minor identifiers.
Eddystone, introduced by Google in 2015, offers a more complex advertising packet format with four different frame types: Eddystone-UID (similar to iBeacon’s UUID), Eddystone-URL (broadcasting web address), Eddystone-TLM (telemetry information about the beacon itself), and Eddystone-EID (an encrypted version of Eddystone-UID for secure applications).
Altbeacon, an open-source specification introduced by Radius Networks, provides a simpler format similar to iBeacon.
The functionality of beacon technologies are different on iOS and Android due to differences in the operating systems themselves. Apple’s strict app guidelines and strong emphasis on user privacy limit the ability of apps to perform tasks in the background. For instance, iOS only allows apps to scan for iBeacon formatted advertisements in the background using the CoreLocation library, not CoreLocation. Eddystone or AltBeacon can only be read in background using CoreLocation. Android offers more flexibility for background tasks and can work with iBeacon, Eddystone and Altbeacon.
Although Eddystone and Altbeacon have their merits, iBeacon is the advertising of choice for most scenarios involving smartphone apps due to the integration with iOS.
While the Covid pandemic is over and we are getting on with our lives, there are still outbreaks that can be particularly disruptive on ships. The cruise market was adversely affected by pandemic and continues to need to be vigilant. Operations on navy and commercial shipping also continue to be affected by on-board outbreaks.
The researchers have devised a system that uses beacons rather than having smartphones detect each another. Mutual smartphone detection is difficult, if not impossible, without using the smartphone contact APIs that are only available to government organisations.
The system identifies risky areas in ships based on the location point encounters. It tracks close contacts using Bluetooth and without WiFi or Internet. A smartphone app provides transmission risk indicators.
A critical aspect of beacon setup is the transmission power (Tx power) setting, which determines the range of communication and the beacon battery consumption. The Tx power is measured in dBm (Decibel-milliwatt) and indicates the strength of the radio signal. The standard range of TX power settings typically falls within -30 dBm to +4 dBm, the ‘standard’ level being 0dBm.
Lower TX power settings, between less than 0 dBm, are used for short-range. Low power settings conserve battery life by minimizing energy consumption, making them ideal for battery-powered beacons. Higher power settings, above 0 dBm are used for long-range communications. However, it is important to note that higher power settings significantly impact battery life.
A change in ± 3dBm is a halving or doubling of power. An approximate rule of thumb is that this halving/doubling affects the battery in opposite way way. For example, going from 0dBm to -3dBm will approximately double the battery life. This is a very rough approximation because the beacon also uses a small amount of power when not transmitting, which is most of the time because the beacon only transmits for a few milliseconds (ms) every configurable 100ms to 10 sec.
A change in ± 3dBm doesn’t halve or double the range. Instead, the range approximately follows inverse square law with distance. Again this is approximate due to antenna characteristics, obstructions and interference. Signal processing at the receiver can also optimise performance and improve on the usable range.
Our recommendation is to start off with the ‘standard’ level of 0dBm. This will provide the battery life quoted by the manufacturer. If you really need more range then increase the power. If the range is further than you require then reduce the power to obtain a better battery life. You can test the range and received radio level using nRF Connect app on a smartphone.
Mohammad Afaneh has unearthed (LinkedIn) a paper by researchers at Centre for Wireless Communications, University of Oulu Finland and Centre for Wireless Communications, University of Oulu, Finland on Experimental Performance Evaluation of BLE 4 vs BLE 5 in Indoors and Outdoors Scenarios.
Bluetooth 5 promises x4 improvement in range over Bluetooth 4. The researchers set up indoor and outdoor experiments to determine the real-life performance. Tests used the Nordic Semiconductor nRF52840 SoC.
The results showed a x2 improvement in line-of-sight range outdoors and up to 20% improvement in non line-of-sight indoors. For example, for Bluetooth 4, with 0 dBm transmit power, the maximum range was 220m. For Bluetooth 5, with 0 dBm transmit power, the communications range was found to be 490m. A x4 range improvement was not achieved in most scenarios and the only situation where this was achieved was when using Bluetooth 5 coded mode with increased (9dBm) transmit power.
It’s still the case that very few beacons support the Bluetooth 5 features. This is mainly because there are very few smartphones with which they can be used. Another observation is that the +9dBm used in the above tests isn’t practical for most battery-based solutions and instead it’s more normal to run at 0dBm or less power. The range also depends on the sending and receiving hardware and antennas. In the extreme case, we have seen a non-battery powered Bluetooth 4 device achieve 4Km line-of-sight range.
The paper also tests the throughput which we haven’t mentioned in this post. Throughput implies GATT connection which isn’t relevant in the context of using beacons.
Nordic Semiconductor, the manufacturer of the System on a Chip (SoC) in the majority of beacons, has published the latest online issue of Wireless Quarter Magazine. It showcases the many uses of Nordic SoCs.
This issue of the magazine highlights the use of Nordic SoCs in the following Bluetooth solutions:
Wearables providing seniors’ healthcare metrics
The Galaxy SmartTag
TraceTag and YardTag smart tags for livestock tracking
Connected rowing machines
A GPS bike computer
The magazine leads with a description of a new SoC the nRF7002 for Wi-Fi 6 IoT applications. There’s also a useful article on Amazon Sidewalk that allows devices to work better indoors and extend reach beyond the home. An in-depth article, ‘How the IoT Can Help Save the World’, explains how IoT is helping countries, communities and companies meet their green responsibilities. There are also two further articles on IoT in warehousing and the use of devices for health and assigned for seniors.
There’s new research by Institute of Electronics and Computer Science, Universite Grenoble Alpes, France on Bluetooth Low Energy Throughput in Densely Deployed Radio Environment (PDF). It looks into coexistence issues when Bluetooth is used in a crowded 2.4GHz frequency band where other devices such as Classic Bluetooth, WiFi, Zigbee and microwave ovens might also be operating.
The paper starts with a theoretical discussion of the throughput of Bluetooth LE.
Experiments used ten Bluetooth nodes to measure Bluetooth application throughput using various connection parameters and different interference sources. Two WiFi routers were used to evaluate the impact of WiFi on the BLE throughput.
The researchers found:
The more Bluetooth devices are working simultaneously, the more drastically Bluetooth throughput is decreasing… The Bluetooth co-interference causes throughput decrease for longer connection intervals. This behaviour could be explained by collisions in data transfer channel.
Also:
The effect of WiFi interference does not depend on the BLE connection interval. In this study, WiFi activity reduced BLE throughput approximately by 30% regardless of the connection interval.
These tests used Bluetooth GATT to form connection between devices. Some applications of Bluetooth LE, such as the use of beacons and AoA direction finding, don’t use GATT other than for initial setup. GATT implies connection between devices while beacons and the sole use of advertising and listening, rather than connection, is a different form of communication not covered by this paper. We have a post on Managing Bluetooth LE Advertising Congestion and Fixing Poor Bluetooth Beacon Radio Signals if you wish to explore this topic in more detail.
