Category: Bluetooth LE

Do Bluetooth Beacons Need a Licence to Use?

Bluetooth Low Energy (BLE) technology does not require a licence for use, making it a popular choice for various devices including smartwatches, fitness trackers, laptops, PCs, smartphones and industrial equipment.

BLE operates in the 2.4 GHz ISM (Industrial Scientific Medical) band, which is licence-free in most countries. This means that anyone can use this frequency range without obtaining a specific permit which has contributed to the widespread adoption of BLE technology. BLE is an open standard managed by the Bluetooth Special Interest Group (SIG), which allows for broad implementation across various devices.

Bluetooth vs WiFi Range

When it comes to wireless connectivity, Bluetooth and WiFi are two of the most widely used technologies. While they serve different purposes, they share some similarities in terms of range and frequency usage. Typically, Bluetooth has similar range as WiFi. Standard Bluetooth connections and WiFi can reach up to 50 meters depending on reflection and blocking.

While standard Bluetooth and WiFi devices have limited ranges, there are special Bluetooth beacons designed for extended range capabilities. These beacons can achieve ranges that surpass typical WiFi connections, sometimes reaching up to 4Km. This extended range is achieved through the use of higher power outputs and additional signal amplifiers. However, it’s important to note that the more extreme long-range beacons are specialised devices requiring power via USB rather than battery and are not representative of typical Bluetooth functionality.

Bluetooth 5 brought significant improvements to the technology, including the potential for extended range. Theoretically, Bluetooth 5 can achieve ranges up to four times that of previous versions in ideal conditions. However, it’s important to understand that most Bluetooth beacons, even those supporting Bluetooth 5, don’t usually utilise these extended range capabilities. This limitation is primarily due to compatibility issues with smartphones.

Most smartphones on the market today don’t support the long-range features of Bluetooth 5. As a result, beacon manufacturers often choose not to implement these extended range capabilities to ensure their devices remain compatible with the widest range of smartphones possible. This decision prioritises broad compatibility over the potential for increased range.

Bluetooth Backward Compatibility

Bluetooth technology is designed to be backward compatible across different versions. Here are the key points about Bluetooth backward compatibility:

General compatibility: Newer Bluetooth versions are typically backward compatible with older versions. This means that devices with newer Bluetooth versions can usually connect to and communicate with devices using older Bluetooth versions.

Classic and Low Energy: There are two main types of Bluetooth: Classic (BR/EDR) and Low Energy (LE). Classic Bluetooth radios are backward compatible with other Classic radios, while LE radios are backward compatible with other LE radios. However, Classic and LE are not directly compatible with each other.

Version-specific compatibility: Bluetooth 5.0 devices can connect to devices using Bluetooth 3.0 and later versions.

Feature limitations: When a newer Bluetooth device connects to an older one, it typically operates at the capabilities of the older device. This means that advanced features of newer versions may not be available when connecting to older devices.

Performance considerations: While backward compatibility ensures basic connectivity, there may be differences in performance, such as audio sync issues or reduced transmission rates when connecting devices with significantly different Bluetooth versions.

Future developments: As Bluetooth technology continues to evolve, backward compatibility remains a priority. For example, the upcoming Bluetooth 6.0 is expected to maintain backward compatibility with previous versions.

It’s important to note that while backward compatibility is a core principle of Bluetooth design, specific device implementations may vary, and some features may require both devices to support the same version and have implemented the relevant part(s) of the specification, for optimal performance.

What is the Beacon With the Shortest Range?

A short-range beacon is useful in scenarios where precise proximity detection is crucial. For instance, in retail environments, it can trigger notifications when a customer is near a till or near a specific product. In museums, it can provide detailed information about an exhibit when a visitor is directly in front of it. Short-range beacons are also valuable for security purposes, ensuring access control in restricted areas by detecting when someone is within a specific, confined space.

The range of a beacon can be adjusted by altering its transmission power, known as Tx Power. Tx Power determines the strength of the signal the beacon emits. By reducing the Tx Power, any beacon’s signal strength can be decreased, effectively shortening its range.

Lowering the Tx Power to reduce the beacon’s range significantly improves battery life. Since the beacon is emitting a weaker signal, it consumes less power. This efficiency is beneficial for maintaining the beacon’s operation over longer periods without frequent battery replacements or recharges.

Beacons can generally achieve a minimum range of 2 to 3 metres. However, it’s important to note that the range can fluctuate over time due to the nature of radio signals, which can be affected by environmental factors such as walls, interference from other electronic devices and physical obstructions.

In addition to adjusting the Tx Power, the range can be fine-tuned by using the Received Signal Strength Indicator (RSSI) at the receiving end. RSSI measures the power level of the received signal, allowing devices such as smartphones (iOS and Android) or computers (like Raspberry Pi) to determine how close they are to the beacon. By setting thresholds for RSSI values in the receiving program code, you can define more precise proximity zones, ensuring that actions are triggered only when the device is within the desired range.

Balancing Bluetooth Throughput and Reliability in Interference-Rich Environments

There’s an interesting new paper titled Modeling the Trade-off between Throughput and Reliability in a Bluetooth Low Energy Connection that provides a comprehensive analysis of the performance of Bluetooth Low Energy (BLE) communication in terms of throughput and reliability under various interference conditions.

The primary objective of the study was to develop and validate mathematical models that predict the throughput and reliability of BLE connections under interference.

Two models were developed, a Throughput Model using a Markov chain approach to predict the throughput of BLE connections under interference, and a Reliability Model that quantified the reliability of BLE connections by considering various transmission parameters and interference levels.

The throughput model was validated through extensive practical experiments under different interference scenarios. The experiments involved varying parameters such as packet length, number of packets, and connection intervals. The results showed a close match between the theoretical predictions and the experimental data, highlighting the accuracy of the models.

As might be expected, the study found that the interference level in the environment significantly affects both throughput and reliability. Higher interference levels (higher BER) reduce both metrics.

There is a non-linear relationship between payload size and throughput. While larger payload sizes can increase throughput in low-interference environments, they significantly reduce reliability and throughput in high-interference conditions.

Increasing the connection interval improves energy efficiency but reduces throughput without affecting reliability. This suggests that connection interval adjustments can optimise energy usage without compromising communication reliability.

Bluetooth devices should be configured based on the specific interference environment they will operate in. For instance, smaller payload sizes are preferable in high-interference environments to maintain reliability.

Bluetooth Beacon Advertising Protocols

We recently came a cross a very useful diagram, from a research paper, that clearly shows the main Bluetooth LE advertising formats for Bluetooth 4.2, used by beacons:


This clearly shows how the formats, iBeacon, AltBeacon and Eddystone, all sit within a Bluetooth LE advertising protocol data unit (PDU). i.e. They are all use standard Bluetooth LE. Notice also that the advertising data is always short which is partly why it doesn’t use much transmit power and battery. Advertising is sent periodically, every 100ms to 10 seconds, depending on the beacon settings. It only takes of the order of 1ms or 2ms to send the advertising which means the beacon can sleep most of the time, another reason for the low power use.

View All Beacons

Anchor-based Bluetooth Low Energy (BLE) 5.0 Positioning

A recent new paper, BLE-Based Indoor Localization: Analysis of Some Solutions for Performance Improvement, focuses on improving the performance of indoor localisation using an anchor-based system based on Bluetooth Low Energy (BLE) 5.0 technology, specifically employing the Received Signal Strength Indicator (RSSI) for distance estimation. Different solutions to enhance this localisation technology’s performance are explored, with an emphasis on combining various approaches to identify the most effective one. These solutions include different RSSI signal conditioning, anchor–tag distance estimation techniques and methods for estimating the unknown tag position.

An experimental analysis was conducted in a complex indoor environment, marked by the continuous movement of working staff and numerous obstacles. The results showed that the exploitation of multichannel transmission, using RSSI signal aggregation techniques, significantly improved the localisation system’s performance, reducing the positioning error from 1.5 meters to about 1 meter.

Other solutions, such as RSSI signal filtering, distance estimation with an empirical propagation model or Machine Learning (ML), numerical optimisation and ML models for estimating the tag’s unknown position, also impacted performance but to a lesser extent. These solutions resulted in either a decrease or an increase in positioning errors, depending on the specific combination of solutions adopted.

The study’s findings suggest that the use of multichannel transmission and the combination of RSSI signals from different transmission channels are crucial for achieving optimal performance. This approach leverages the full potential of BLE 5.0 technology and is the most significant factor in reducing positioning errors. The paper concludes that the results can guide designers in choosing appropriate solutions based on the desired accuracy of the localisation system. However, it’s noted that the results are specific to the tested conditions and may vary under different operating scenarios.

Bluetooth 4 is Still Dominant

For technology, newer versions typically overshadow their predecessors, but the Bluetooth beacon market has been different. Despite the introduction of Bluetooth 5, the significant majority of beacon applications continue to rely on Bluetooth 4. This is not a mere reluctance to adopt newer technology but a practical decision rooted in compatibility concerns, especially with existing smartphones.

Bluetooth 5 arrived with much fanfare, offering significant improvements over Bluetooth 4. It promised doubled speed, quadrupled range and an eightfold increase in data broadcasting capacity. These advancements opened new possibilities for IoT applications, making it an attractive prospect for beacon technology. However, this leap forward did not translate into immediate widespread adoption in the beacon ecosystem.

The core issue hindering the widespread adoption of Bluetooth 5 beacons lies in device compatibility. The majority of smartphones in circulation still operate on older Bluetooth versions. While Bluetooth 5 is backward compatible, meaning it can work with devices supporting older versions, the reverse is not true. A beacon using Bluetooth 5’s advanced features cannot be fully used by a device that only supports Bluetooth 4.

Bluetooth 4, particularly 4.2, introduced Low Energy (LE) technology, which was a game-changer for battery-powered devices like beacons. It provided an efficient way to transmit small amounts of data over a reasonable range without draining the battery. This efficiency made Bluetooth 4 beacons incredibly popular for a wide range of applications, from retail marketing to indoor navigation and asset tracking.

In real-world scenarios, the extended range and speed of Bluetooth 5 are often unnecessary for typical beacon applications. Most beacon use-cases, like sending notifications or tracking assets, require neither long-range transmission nor high-speed data transfer both of which usually cause more Bluetooth battery use. Bluetooth 4’s capabilities sufficiently meet these requirements, making it a practical choice.

The transition to Bluetooth 5 beacons will likely charge a little as the market penetration of Bluetooth 5-enabled smartphones increases. However, only applications demanding higher data throughput and longer ranges will gravitate towards Bluetooth 5. However, until there is a significant shift in the smartphones, Bluetooth 4 will continue to be the backbone of beacon technology.

In conclusion, while Bluetooth 5 offers technological enhancements, the beacon market’s reliance on Bluetooth 4 is underpinned by practical considerations. Compatibility with the existing smartphone ecosystem and the adequacy of Bluetooth 4 for current applications justify its continued dominance.

Which Beacons Transmit a MAC Address?

A MAC (Media Access Control) address is a hardware identification number that uniquely identifies each device. In the context of Bluetooth, a MAC address is used to identify a specific Bluetooth device, such as a smartphone, headset or a Bluetooth beacon. All beacons transmit a Bluetooth MAC Address which is a 48-bit address usually represented in hexadecimal format like this: 0123456789AB.

All devices such as smartphones can see the incoming MAC addresses that are sent as part of the device discovery stage rather than the main Bluetooth LE advertising payload. iOS is a bit strange and non-standard because it hides detected Bluetooth MAC address from apps, and hence from users, when detecting beacons and other Bluetooth devices.

No such restriction happens on Android or any other device. The rationale is probably that Apple wants you to use their ids, the iBeacon UUID, major and minor or the Peripheral Id rather than the MAC address. Apple also probably think they are protecting privacy in some way. A few beacons and other devices such as sensors and fitness trackers additionally put the MAC address into the advertising payload which circumvents Apple’s restrictions and allows reading of the MAC address by apps.

Does Bluetooth Signal Go Through Walls?

One question that often comes up is whether Bluetooth signals can go through walls. The answer is a bit more nuanced than a simple yes or no.

Bluetooth operates on a 2.4 GHz ISM (Industrial, Scientific, and Medical) radio frequency band. This frequency is also shared by other wireless technologies like Wi-Fi. Bluetooth signals are designed to be robust but are generally short-range, typically extending up to 50 metres. As it uses the same frequency as Wi-Fi which most people have a knowledge of range of, a very rough approximation is to think of Bluetooth as being similar to Wi-Fi.

The material of the wall plays a significant role in how well a Bluetooth signal can pass through it. Materials like drywall, glass and wood are generally more permeable to Bluetooth signals. In contrast, concrete, brick and metal can severely limit or block the signal altogether.

The strength of the Bluetooth signal also matters. Higher-powered Bluetooth devices can transmit signals that are more likely to pass through walls. However, even with a strong signal, the quality may degrade as it passes through obstacles.

The distance between the transmitting and receiving devices will also impact the signal’s ability to pass through walls. The closer the devices are to each other, the more likely it is that the signal will successfully penetrate the wall.

In practical terms, while it’s possible for Bluetooth signals to go through walls, the quality and reliability of the connection can be compromised.

So, does Bluetooth signal go through walls? The answer is yes, but with caveats. The type of wall, the strength of the signal, interference from other devices, and the distance between the connected devices all play a role in determining how well a Bluetooth signal can penetrate walls.