faq – BeaconZone Blog

What Can Block Beacon Signals?

We often get questions asking what kinds of things can block Bluetooth signals and enquiries about the relative blocking of different materials.

Metal obstructions or metal-based surfaces such as metal-reinforced concrete cause the most blocking followed by other dense building materials such as plaster and concrete. Next comes water that you might not think would be a problem but, as people are made up of 60% water, bodies blocking Bluetooth signals can be a significant factor. Least blocking are glass (but not bulletproof), wood and plastics.

Blocking can be caused by wireless noise as well and physical obstructions. This includes electrical noise from other electrical equipment as well as interference from devices using the same 2.4GHz frequency. WiFi on 2.4GHz causes negligible interference.

In extreme cases, a very large number of Bluetooth devices can cause interference with each other because only one can advertise at a time without there being collisions and hence lost data. The maximum number of Bluetooth devices depends on how long and how often the Bluetooth devices transmit. It also depends on whether devices are just advertising or additionally using GATT connections. Bluetooth also has adaptive frequency hopping that helps reduce packet interference.

We have a deeper analysis of interference in the post on Bluetooth LE on the Factory Floor.

Which Beacons are Compatible with iOS and Android?

We often get asked the question which beacons are compatible with iOS and Android. All beacons, whether iBeacon, Eddystone or sensor beacons can be used with iOS and Android. The compatibility is achieved through the implementation of common Bluetooth standards on these mobile platforms.

However, there are some caveats:

Android only supported Bluetooth LE as of Android 4.3. Older devices can’t see Bluetooth beacons. Over 99% of users are on Android 4.3 or later so most people can see beacons.
Apple iOS doesn’t have background OS support for Eddystone triggering. While iOS apps can scan for, see and act on Eddystone beacons, the iOS operating system won’t create a notification to start up your app when there’s an Eddystone beacon in the vicinity.
Apple can’t see beacon’s or other Bluetooth devices’ MAC address or iBeacon ids due to over zealous privacy concerns. It can see iBeacons but you have to pre-declare, already know, their ids.

Rather than beacons being compatible with iOS/Android, we find that there are more problems with particular Android devices not seeing beacons, when in background, due to some manufacturers killing background services.

Also see Which Beacon’s Are the Most Compatible?

View iBeacons

What is a Bluetooth WiFi Gateway?

A Bluetooth WiFi gateway is a device that connects Bluetooth devices to a WiFi network. It allows Bluetooth devices, such as sensors, beacons, or other IoT devices, to communicate with a WiFi network and exchange data with other devices on the network or remote servers or the cloud.

Bluetooth WiFi gateways have both Bluetooth and WiFi capabilities and are able to bridge the communication between these two technologies. They are often used in IoT (Internet of Things) applications, where they can be used to connect a variety of Bluetooth devices to a WiFi network, allowing them to communicate with each other and exchange data.

Gateways are configured through web pages hosted within the gateway itself. These configuration pages allow you to set up the WiFi access point that the gateway connects to, the destination server, typically using protocols such as HTTP or MQTT and determine which Bluetooth devices are allowed to be relayed. The gateway setup also includes filtering options to manage the data sources based on the Bluetooth advertising and/or Bluetooth MAC address. Power for the gateways is generally supplied through a USB connection, which is used solely for power delivery and not for data transfer.

There are also gateways that connect via Ethernet rather than via WiFi.

View Gateways

What is iBeacon Measured Power?

Most beacons’ configuration app have a setting for iBeacon ‘measured power’ or ‘RSSI at 1m’. This doesn’t change the power output by the beacon. Instead, it’s a value that’s put into the advertising data that declares to receiving devices what the power should be at a distance of 1 meter from the beacon. Receiving devices such as smartphones and gateways can use this to help calibrate a calculation to determine the rough distance from the beacon.

You don’t usually change this value and it’s actually rarely used. In most cases the value is irrelevant and can be ignored. However, if your app or receiving device does use this value, it’s best to first do some tests to see what the power level is at 1m in your particular situation. Things like the physical environment, blocking and beacon orientation can affect the actual power level at 1m. Set the value according to your particular scenario.

Read more about transmitted power (as opposed to measured power)

Do You Have an Estimote Alternative?

Several companies have informed us that Estimote is no longer responding to enquiries about purchasing their beacons. It appears they are now more focused on promoting and selling their UWB (Ultra Wideband) tags instead.

This shift is unfortunate for companies that have integrated their solutions with Estimote’s beacons, SDK, and platform. Estimote’s approach, which involves manufacturing their own custom hardware and restricting their platform to only work with their own beacons, means there is no direct replacement for their older products.

However, if your application doesn’t rely on the Estimote SDK and simply detects iBeacon advertisements using the standard Bluetooth libraries available in iOS and Android, then you are not tied to Estimote’s hardware. In such cases, you are free to use any iBeacon. For more details, please refer to our post regarding beacon compatibility.

Read about the advantages of generic beacons

Does Bluetooth LE Work the Same Way in all Countries?

Bluetooth technology operates on a global scale using the 2.4 GHz ISM band, allowing devices to be used internationally without specific adaptations for local radio spectrum regulations. The Bluetooth Special Interest Group (SIG) ensures that all devices meet international standards for compatibility and interoperability.

However, there are certain regulatory considerations that vary by country. Some nations require Bluetooth devices to undergo type approval, for example CE (for Europe) or FCC (for USA), to ensure they adhere to local standards. Additionally, power output limitations for Bluetooth devices can differ from one country to another. For example, Australia permits a maximum of 200 mW e.i.r.p. within a specific frequency range, while most European countries adhere to standard ISM band regulations.

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.

Can an iBeacon Send Users to a Website?

The short answer is no, iBeacons cannot directly send users to a website. iBeacons do not have the capability to push content or URLs to devices automatically. Instead, they rely on compatible apps to detect their presence and take appropriate actions which can include sending the user to a web site.

There used to be a mechanism in Android that used the Eddystone-URL advertising format but this has since been discontinued by Google.

How to Calibrate Temperature Sensor Beacons?

We have several clients using the temperature/humidity sensor beacons in industrial situations. A question we have had is how is the temperature/humidity calibrated? For scenarios that require monitored temperature/humidity, it’s often necessary to show the readings have been calibrated over time.

M52-SA Sensor beacon

Most sensor beacons don’t have a calibration certificate. The long term drift of the sensor is <0.04C/yr and <0.5 RH/yr so in most applications it doesn’t usually need calibration. If you need accuracy better than this you will usually need to calibrate in the software of the phone/device that receives the beacon signal. That is, you will need to periodically measure the real temperature/humidity using another calibrated instrument and apply any offset to the read values.

S5 Sensor beacon

Another option is to use the one beacon, the S5, that does have a temperature/humidity calibration certificate.

Beacons for Spying?

There’s lots of information on Bluetooth beacon security, Bluetooth attacks and using beacons to track individual user data but these are known, small risks we might expect. What about unknown things such as espionage?

Recently, a prospective customer posed a different question: How can we ensure that purchased beacons are not engaging in activities beyond their intended purpose, such as eavesdropping or transmitting sensitive information? This question becomes even more pertinent when considering beacons manufactured overseas that might be deployed in sensitive locations.

Typically, a single SoC chip on the beacon’s simple Printed Circuit Board (PCB) is responsible for all operations. Upon examination, if there are no additional, unexpected, chips on the PCB, it limits the beacon’s ability to perform unexpected tasks. If the hardware is not compromised, the only factor to consider is the standard, usually Nordic Semiconductor, System on Chip (SoC) used in the beacons. This means that any potential spying would likely be restricted to software in the SoC rather than hardware modifications.

Let’s assume beacons can only exploit the capabilities that the standard SoC chip provides. These usually include Bluetooth, ANT, 802.15.4 and other proprietary and non-proprietary 2.4GHz protocols. Crucially, beacons are designed primarily to send signals rather than receive them. They transmit signals every millisecond, typically every 200ms to 1000ms, to maintain low battery consumption. For a beacon to listen or scan for information, it would require significantly more power, thus drastically reducing battery life. Similarly, relaying, perhaps via covert channels, any gathered information would also deplete the battery swiftly. Therefore, any huge deviation from the expected battery life could be a tell-tale sign of unauthorised activities.

Given that beacons usually only send data, they cannot capture sound or video without additional, noticeable components. When they are listening using the protocols they are designed for, the information they could gather would be limited and lack context, such as identifying what they have seen or the specific location.

While the theoretical possibility of beacons being used for spying exists, it is easily detectable due to the easily examined, simple hardware, limited capabilities of the SoC and the significant power requirements for any additional activities. By understanding the simplicity, limitations and functionalities of these devices, businesses can better safeguard against potential espionage.

Read about our consultancy for more advice