iBeacon is a protocol developed by Apple that uses Bluetooth Low Energy (BLE) to transmit a signal that can be picked up by nearby devices, such as smartphones. The iBeacon protocol format is based on the standard BLE advertising packet, which is a small amount of data that is broadcast at regular intervals.
The iBeacon protocol format includes the following components:
Proximity UUID: This is a unique identifier that is used to identify a group of beacons. It is typically a 128-bit value.
Major and Minor: This is a 16-bit value that is used to identify a specific beacon within a group of beacons.
Measured Power: This is a value that is used to indicate the expected signal strength of the beacon at a distance of one meter. This value is used to estimate the distance between the device and the beacon.
Together, the Proximity UUID, Major, and Minor values make up a unique identifier for each beacon, which can be used to determine the beacon’s location or trigger an action on a nearby device.
It’s worth noting that the iBeacon protocol is one of the many implementations of BLE beacons, and other protocols and vendors have different formats.
RSSI stands for Received Signal Strength Indicator. It is a measure of the power level of a radio signal being received by a device, for example a smartphone, in dBm (decibel-milliwatts). The RSSI is accessible to receiving devices via APIs such as the standard iOS and Android Bluetooth libraries.
The RSSI value is typically used to get an indication of the distance between a device and a beacon. A higher RSSI value indicates a stronger signal and therefore a closer proximity to the beacon, while a lower RSSI value indicates a weaker signal and a farther proximity to the beacon. Note that RSSI is usually -ve so a larger negative more usually indicates the beacon is further away.
RSSI is not a perfect measure of distance, as it can be affected by factors such as the environment and the type of device that is receiving the signal. However, by comparing the RSSI value of a beacon’s signal with the known transmission power of the beacon, it is possible to estimate the distance between the device and the beacon.
RSSI is commonly used in wireless communications such as WiFi, Zigbee, Bluetooth and cellular networks to measure the signal strength of the received signal. It is also used to estimate the quality of the signal, and to determine if the signal is strong enough to maintain a reliable connection.
RSSI is not a standard or a regulated measure and varys depending on the technology and the manufacturer of the device.
The relationship between RSSI and distance is not linear, and can vary depending on the environment and the type of device that is receiving the signal. In general, as the distance between a device and a beacon increases, the RSSI value decreases. However, the rate at which the RSSI value decreases with distance can vary depending on factors such as the environment and the transmission power of the beacon.
In free space, the RSSI value decreases at a rate of approximately 6 dB per doubling of distance. This is known as the inverse square law, which states that the power of a signal decreases proportionally to the square of the distance from the source.
Inverse square law
However, in a real-world environment, the rate of decrease can be affected by factors such as walls, obstacles, and interference from other devices, which can cause the signal to weaken faster or slower than expected.
It’s also worth noting that the RSSI value can vary depending on the type of device that is receiving the signal, as well as the type of radio technology used. The sensitivity of the device’s radio receiver will also affect the received RSSI value, a more sensitive device will be able to detect weaker signals at farther distances than a less sensitive device.
While equations can be used to infer distance from RSSI, the above factors mean the most accurate way to determine distance is to compare with previously measured RSSI-distance values.
If accurate distance is essential, up to about 3m, consider using a beacon such as the iBS03R that uses a time of flight (ToF) sensor rather than using RSSI.
Eddystone-URL is a format for Bluetooth Low Energy (BLE) beacon advertisements. It is an open format developed by Google and designed to be transmitted by beacons to nearby devices, such as smartphones and tablets. The format allows beacons to broadcast a URL which can be used to direct users to a specific web page.
In other words, Eddystone-URL is a way for ‘things’ with attached beacons to communicate with nearby devices and provide them with a link to a webpage. This can be used for a variety of purposes, such as providing location-based information, coupons, or other types of content to users. It can be used in a wide range of applications, including retail, transportation and tourism.
Eddystone-URL works by broadcasting a URL in a Bluetooth advertisement packet. When a device with a compatible BLE receiver, such as a smartphone, comes within range of the beacon, it can receive the advertisement packet and decode the URL. The user can then open the URL in a browser on the device.
An app is needed on iOS and Android such as Beaconstac NearBee, the Physical Web Association app or your own custom app. If you create your own app, consider using iBeacon instead of Eddystone URL advertisements for easier processing on iOS (also works on Android). The iBeacon ids can be mapped to URLs in the app. This is often better because the mapping can be changed, for example on a server, rather than having to physically access the beacon to change the URL.
There can be several reasons why the specification for a beacon listed on our site doesn’t match that shown on a manufacturer’s web site or 3rd party sales platform.
Beacon descriptions on many sites are often written by non-technical staff and non-English speakers. This means that there can be misunderstandings and errors.
Some descriptions purposely over-fill descriptions with incorrect information or competitor’s product information so as to attract interest. The actual specification becomes clearer after you have asked the right questions or, in some cases, when you receive the beacons!
Some descriptions are of cloned products with dubious provenance rather than products from the original manufacturer.
It’s common for descriptions to mention optional features that are only available via manufacturing customisation. They are sort of saying the specification is possible, but you will find you have to pay a lot extra for a custom version.
We spend a long time assessing beacons and only list the features actually provided by the beacons we sell. We have a deep understanding of beacons that can be accessed via our support and consultancy services.
Bluetooth beacons are small, low-power devices that use Bluetooth technology to broadcast a signal to nearby devices. These signals can be used by nearby devices to determine the location of the beacon, or to trigger certain actions, such as sending a notification or displaying information on a mobile device.
There are several different types of Bluetooth beacons, which can be classified based on their shape, size, and power source. Some examples of different types of Bluetooth beacons include:
USB beacons: These are small, USB-powered beacons that can be plugged into a computer or other device to broadcast a Bluetooth signal. They are often used in retail or other public settings, where they can be plugged into a computer or display to broadcast information to nearby devices.
Coin-cell beacons: These are small, battery-powered beacons that are about the size of a coin. They are often used in portable or wearable applications, such as tracking the location of a child or pet, or triggering a notification in a mobile app.
Wall-mounted beacons: These are larger, wall-mounted beacons that can be installed in a fixed location, such as a retail store or office building. They typically have a larger battery, longer range and higher power output than other types of beacons, allowing them to broadcast a signal over a larger area.
Outdoor beacons: These are rugged, weather-resistant beacons that are designed to be used outdoors. They often have a longer range and higher power output than other types of beacons, and are designed to withstand exposure to rain, snow, and other harsh conditions.
Overall, there are several different types of Bluetooth beacons, which can be used in a variety of applications. The type of beacon that is best suited for a particular application will depend on factors such as the range and power requirements, as well as the environment in which it will be used.
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 Nordic SoCs in the following Bluetooth solutions:
Bluetooth LE wildlife tracking solution
Tracker notifications to parents if their child wanders off from a caregiver
Bluetooth 5 monitor for refrigeration equipment
Indoor asset tracking platform monitoring essential medical equipment in hospitals
It’s interesting that some of these companies have chosen to create their own hardware even though these scenarios are achievable using generic beacons. Sometimes, a custom hardware product has more credibility for investors and customers. However, similar levels of kudos can be achieved by branding and/or over-casing generic devices with much less cost and risk.
The magazine also has an interesting article on how smart toy manufacturers are engaging and educating children.
The MBM01 is special because it has a very long range of up to 600m. It also has a long battery life of up to 10 years provided by the included lithium battery. This beacon is also waterproof to IP67.
As Bluetooth and WiFi both use the 2.4GHz band, is it possible that they can interfere with one another? John-Paul Little has a old post on Can iBeacon deployments cause WI-FI interference. The conclusion is no, it won’t, as there’s negligible overlap between the WiFi and Beacon frequencies:
The 2.4GHz band is split into smaller frequencies, called channels, such that more than one technology can share the same band.
Also, at the practical level, we have used WiFi and (many) Beacons together on many projects and we have never experienced a problem. Although still rare, it’s more likely that multiple Bluetooth devices can interfere.
It’s often mentioned by the press and even some platform providers that beacons can transmit content, for example text, images or other multimedia content to smartphones. People contacting us expect this to happen (without an app) and we end up spending a lot of time explaining how it really works.
Beacons don’t send content to phones and instead they send an id (or URL) that an app uses to get content from a server. This doesn’t work without an app.
Bluetooth beacons can last a long time on battery power, up to 5 years in some cases. However, long battery lifetimes require larger batteries that are more bulky and result in devices that are less suitable to wear.
The smallest beacons, most suitable for wearing, have small CR2032 coin cell batteries that can only typically last of the order of a few months. The solution is to use rechargeable beacons. They all charge via some sort of USB, either plugin, via a clip or magnetic connector.
The iB001W, supporting iBeacon and Eddystone, comes with a small charging cradle that plugs into the beacon.
The H1 Wristband is waterproof and has an acceleration sensor that supports motion triggered broadcast to save battery life. It charges via a clip.
The F1 is waterproof and has an acceleration sensor for motion triggered broadcast and also has a SOS button. It charges via a magnetic connection cable.
The B10 has an acceleration sensor but additionally makes this information available via advertising. It also has an SOS button and charges via a magnetic connector.
The waterproof W2-P5202D3 is a fitness tracker style device that advertises iBeacon, Eddystone and acceleration.
