What are Bluetooth Tunnel Beacons?

This is a feature in Google Maps on Android that improves navigation through tunnels, addressing the long-standing challenge of maintaining accurate location tracking when GPS signals falter.

Historically, tunnels have posed a significant challenge for digital navigation tools, primarily due to the inability of GPS signals to penetrate the thick layers of earth and concrete. This often results in a loss of real-time location tracking. However, Google Maps has improved the situation through the introduction of Bluetooth tunnel beacons, a feature that uses the power of Bluetooth technology to offer an unprecedented level of location accuracy in subterranean environments.

Bluetooth tunnel beacons operate by emitting signals that are received by a user’s smartphone, providing precise location data to the device. This feature, using technology already implemented by Google-owned Waze utilises these signals in conjunction with the device’s mobile connectivity. Together, they deliver navigation assistance, mirroring the capabilities of a traditional GPS connection.

The feature appears under Settings > Navigation Settings and under the ‘Driving Options’ section near the bottom. The feature is disabled by default, and is described as: ‘Scan for Bluetooth tunnel beacons to improve location accuracy in tunnels’.

The effectiveness of Bluetooth tunnel beacons, however, depends on the presence of these beacons within tunnels. Waze has already installed these beacons in several major cities around the world, such as New York City, Chicago, Boston, Paris, Rio de Janeiro and Brussels.

Why is There a Bluetooth Beacon in My Hotel Room?

The presence of a Bluetooth beacon in your hotel room is likely part of the hotel’s efforts to enhance guest experience and operational efficiency. These beacons are used for various purposes.

These beacons can help in providing location-based services. For example, if the hotel has a mobile app, it might send you notifications about special offers or events based on your location within the hotel.

In larger hotels, these beacons can assist guests in navigating to facilities like the gym, restaurant, or conference rooms. They can help the hotel staff in monitoring and managing room status, like whether the room is occupied or needs cleaning, thus improving efficiency.

In the context of health and safety, especially post-COVID-19, such technology can facilitate contactless check-ins and check-outs, or even contactless room service. Hotels may use these beacons to collect data on guest movements and preferences to improve their services and tailor their offerings.

How Much is iBeacon?

There are different beacon models that contain different battery sizes that mainly determine the beacon cost. Beacons with small coin cell batteries cost of the order of €10, $10, or £10. Larger battery beacons with sensors cost up to €30, $30, or £30 or more.

It’s possible to get lower cost beacons direct from China but hidden shipping, money transfer, import duty, import tax and carrier import disbursements inflate the cost. Most brands work ‘just in time’, only manufacturing once they have received payment thus delaying order by weeks or months during holiday periods. Furthermore, they all use freight forwarders, through Hong Kong, that take up to an extra 10 days.

Why is There Variation of RSSI?

We sometimes get asked whether a beacon is faulty because a customer is seeing a lot of fluctuation in the Received Signal Strength Indicator (RSSI) values, even in a seemingly stable environment and with no change in distance. The short answer is: this is normal. The reason for this lies in the complex nature of radio signals and how they interact with the environment.

Radio signals are susceptible to a variety of factors that can affect their received strength. When a beacon sends out a signal, it doesn’t just travel in a straight line to the receiver. Instead, it disperses in multiple directions and can bounce off walls, floors and other objects.

Reflections can cause the signal to take different paths before reaching the receiver. Each path can have a different length and, therefore, a different time delay. This results in a phenomenon known as multipath fading, where multiple copies of the signal arrive at the receiver at slightly different times. This can cause fluctuations in the RSSI values you observe.

While reflections are a primary cause of RSSI fluctuation, they are not the only one. Other physical changes in the environment can also contribute to this variability. For example, the presence of people moving around can affect the signal, as the human body is mostly water and can absorb radio frequencies. Similarly, other electronic devices emitting radio frequencies can interfere with the signal, causing further fluctuations.

To get a more accurate understanding of the signal strength, it’s advisable not to rely on a single RSSI value. Instead, you should look at many RSSI values over a period of time and calculate the average. This approach helps to mitigate the effects of temporary fluctuations and provides a more stable and reliable measure of signal strength.

Many people, particularly researchers, have looked into the intricacies of RSSI and its variability. Various algorithms and methods have been developed to improve the accuracy of RSSI-based distance estimation and location tracking. For those interested in a deeper understanding or potential solutions to this issue, we recommend looking at the articles tagged RSSI and RSSIStability on our blog.

What is the Difference Between Beacon and iBeacon?

iBeacon is a protocol designed by Apple that sits on top of, or uses, the Bluetooth LE protocol. Think of Bluetooth LE as a standard mechanism for sending a short amount of information that can be anything. In the case of iBeacon this ‘anything’ is the UUID, major, minor and a power calibration value called the measured power. We have a post explaining these iBeacon values.

Can I Use My Phone as Bluetooth Beacon?

A question that often arises is, “Can I use my phone as a Bluetooth beacon?” The answer is ‘yes’.

Before we get into the details, it’s essential to understand what a Bluetooth beacon is. In simple terms, a Bluetooth beacon is a small wireless device that transmits a periodic signal to other Bluetooth-enabled devices within its range. This technology is often used for indoor positioning, sensing and other location-based services.

Technically, yes, a smartphone can function as a Bluetooth beacon. Both Android and iOS platforms offer apps to turn your phone into a beacon transmitter. However, there are some caveats.

Using your phone as a Bluetooth beacon can be a significant drain on your battery. Beacons are designed to be low-energy devices that can run for years on a single battery. Your phone, on the other hand, has many other functions that consume power, so using it as a beacon will lead to the need for frequent charging.

The range of a dedicated Bluetooth beacon can be up to 100 metres, depending on the model and settings. A smartphone’s Bluetooth range is generally much shorter, limiting its effectiveness as a beacon.

While there are apps such as Locate Beacon, Beacon Simulator (for iOS), Beacon Simulator, nRFConnect (for Android) that can turn your phone into a beacon, these are often not as reliable or feature-rich as dedicated beacon hardware. You won’t be able to change all the settings such as power, advertising period and advertising type as you would with a dedicated hardware beacon. Additionally, running such an app in the background may interfere with other phone functions and some phones eventually close long running services.

Despite these limitations, there are scenarios where using your phone as a Bluetooth beacon could be useful. If you’re a developer or a business looking to experiment with beacon technology, using a phone can be a cost-effective way to test your ideas before investing in dedicated devices.

While it’s possible to use your phone as a Bluetooth beacon, it’s generally not the most efficient or reliable method for most applications. However, for personal use or small-scale use, it can serve as a convenient alternative. If you’re considering implementing beacon technology on a larger scale, investing in inexpensive dedicated hardware is usually the better option.

View Bluetooth beacons

How Far Can a Bluetooth Beacon Measure Distance?

A common misconception is that beacons can measure distance. In reality, beacons, with the exception of some specialist social distancing beacons and sensor beacons with an additional distance sensor, are designed to send signals rather than receive them.

Instead, measuring distance happens on the receiving end. Devices such as smartphones are equipped to detect these beacon signals. When a beacon sends out its Bluetooth radio signal, the receiving device knows the received signal strength (RSSI). This RSSI can be used to infer the distance between the beacon and the device.

In the proximity of a few metres, the variation in RSSI is significant enough to deduce the distance with a reasonable degree of accuracy. However, as the distance increases, the variation in RSSI becomes less pronounced. This means that while you can determine if a beacon is close or far away, pinpointing an exact distance becomes challenging.

For example, the iOS programming API, CoreBluetooth, provides classifications for the detected beacon signals. These classifications are ‘immediate’, ‘near’, and ‘far’. They don’t give a precise measurement in metres or feet but rather a general idea of the beacon’s proximity.

In terms of maximum range, depending on the specific beacon, it can be detected from distances up to 50m or even 100m. However, as mentioned earlier, at these longer ranges, the RSSI doesn’t provide a clear indication of exact distance. Instead, it offers a more general sense of whether the beacon is nearer or farther away.

What is the Difference Between iBeacon and Eddystone?

iBeacon, a standard developed by Apple, was introduced in 2013 as part of the iOS 7. It’s based on Bluetooth Low Energy (BLE), a power-efficient variant of Bluetooth technology. The strength of iBeacon lies in its background support on iOS devices, which allows for easier detection of beacons.

Google introduced Eddystone in 2015. This protocol for beacons was developed to embrace a broader range of uses. Eddystone offers multiple frame types to cater to various data needs like URLs, unique identifiers and sensor data. One most distinctive feature of Eddystone was the Eddystone-URL, where the beacons could send out a web address. However, this has been limited by the discontinuation of Google Nearby in Android.

Despite the differences in their design and features, both iBeacon and Eddystone share common ground in their use of standard Bluetooth advertising. They send different data in the same standard Bluetooth advertising packets. This shared aspect of technology ensures that they can both communicate effectively to both iOS and Android.

While Eddystone’s versatile frame types and open protocol initially made it appealing, it has seen a decline since the discontinuation of Nearby in Android. Currently, most new systems requiring smartphone applications to detect a beacon opt for iBeacon.

However, when it comes to locating and detection using gateways rather than smartphones, iBeacon vs Eddystone becomes less relevant and the beacons’ Bluetooth MAC addresses are usually used. The advertising packets can instead be used for sensor data, for example, temperature and humidity.

View iBeacon Beacons
View Eddystone Beacons
View Sensor Beacons

Can I Set the Maximum Distance the Beacon Transmits?

Many people inquire about adjusting the transmission distance of a beacon. They often wish to either conserve battery or restrict the range at which a beacon is detectable.

While some third-party platforms and SDKs offer distance settings, it’s a misconception to think you can directly set the distance. What you’re actually adjusting is the transmission power, which in turn influences the transmission distance. But since this involves radio waves, which are prone to reflections and interference, it’s impossible to guarantee that a specific power will equate to a precise distance.

When using an app to detect beacons, you can employ the Received Signal Strength Indicator (RSSI) to focus on those within a desired range. However, it’s challenging to precisely correlate RSSI with the actual distance.

Some wonder if they can set the distance in terms of centimetres, similar to NFC. Typically, this isn’t feasible because even at their lowest power setting, most beacons transmit over a distance of about a metre.

Rather than asking if the transmitter’s distance can be minimised, it might be more practical to configure the receiver to disregard detections from further away. By using the RSSI value on the receiving app or another Bluetooth scanning device, you can filter out distant beacons. Specifically, you can dismiss detections with an RSSI below a certain threshold, allowing you to focus on detections within a centimetre range.

We have an article on Choosing the Transmitted Power.

Can Bluetooth Beacons Track Individual User Data?

Bluetooth beacons themselves are generally not designed to track individual user data. They are small devices that transmit a Bluetooth signal at regular intervals, which can be picked up by smartphones or other Bluetooth-enabled devices within a certain range. The primary function of a beacon is to broadcast its presence and certain identifying information such as a unique ID.

However, the apps on your smartphone that interact with these beacons could potentially collect and store data about your location or behaviour. For example, a retail store might use beacons to send promotional messages to your phone when you’re near a particular product. The app on your phone that interacts with the beacon could collect data on which promotions you’ve seen, how long you spent in a particular area of the store and other information.

While the beacon itself is not tracking you, the software that interacts with it could be. It’s essential to be aware of the permissions you’re granting to apps on your phone, particularly those that request access to your location services.