If you have been following our posts on Bluetooth 5, you might be wondering how one Bluetooth device can communicate to many devices, some of which might be legancy Bluetooth 4.
There’s a new video from Nordic Semiconductor (who produce the System on a Chip – SoC – inside most beacons) where the new long range mode is used while connecting to up to 20 devices. These can be different PHYs meaning that different capabilities, for example high speed vs long range vs legacy) can be connected at the same time.
We just received the 210L ultra-long 200m range beacon into stock.
Most beacons tend to have a range of 30m, 50m or 100m. The normal output is 0dBm but they can be boosted to +4dBm to achieve the maximum ranges. Read our article on Choosing the Transmitted Power for more information.
The 210L beacon transmits at +10dBM which is the maximum allowable for this class of Bluetooth 4 device. This is just over 3x the power of a beacon transmitting at 0dBm. Hence, there’s respective reduction in battery life.
This Bluetooth Class 1, CE RED certified beacon transmits, iBeacon and Eddystone, between 1000m and 4000m depending on the receiving device.
There are new iOS and Android apps that allow up to 10 channels that can transmit anything: Eddystone-UID, Eddystone-URL, iBeacon or AltBeacon. You can still set up by sending AT commands through the laptop/desktop USB com port opening up the possibility of the advertising changing programmatically over time, for scenarios such as changing media displays.
This beacon is especially suitable for large open areas such as stadiums where it can replace 10s or 100s of beacons with shorter range.
Beacons vary in their range. The smaller battery beacons tend to have smaller 30m to 50m ranges to make the most of battery life. Larger battery beacons tend to have ranges up to 100m. Then there’s longer range beacons with ranges over 150m.
One thing to understand is what can block signals. In our experience, when a signal gets blocked, there’s no point trying beacons with longer ranges in the hope they will push the signal through the physical obstructions. Longer range beacons only work long range when there is unobstructed line of sight.
Two interesting issues with the initial trial were:
Slow detection time meant users at bus stops were being notified too late
Placing beacons behind the windscreens of busses, the 80m range wasn’t sufficient
While the article doesn’t explain how the slow detection time was solved we suspect it had something to do with the app having to connect to get information. This information might have been bus information or something to do with the beacon platform. Caching information or turning off advanced functionality that required the app to connect will have solved the problem. Alternatively, it could have been that the time between beacon advertising was too long preventing it from being picked up quickly by the app.
The 80m range was solved by configuring the beacons to be more powerful and transmit to 160 meters. Unless the beacon was already transmitting at less than normal (0dBm) power it wouldn’t have been possible to double the range by re-configuring the power. Most beacons go up to +4dBm which, while providing over double the power, wouldn’t have doubled the range. It’s more likely they had to use a different beacon with integrated power amplifier such as those in our Ultra Long Range.
We now have the white version of the iB003N-PA in stock. The iB003-PA is our longest range beacon and can reach up to 300m in open space. Other features of this beacon include motion triggered broadcast, accelerometer sensor (in advertising data), the ability to send iBeacon & Eddystone simultaneously and waterproofing.
We check beacons as they come into stock because we invariably get a few that are dead on arrival. We had a faulty iB003N-PA this time so this gave us the opportunity to open one up. Here’s the pcb:
The largest chip is the N51822 SoC found in many beacons. At the very top is the PCB antenna. The thing on wires in the middle is the buzzer. The chip at the top is the RFAXIS X2401C 2.4GHz RF front end that gives this beacon its long range.
Most people imagine Bluetooth beacons transmit equally in all directions. However, this isn’t usually true. The 2.4 GHz frequency that beacons use is easily blocked or affected (through electronic resonance) by items such as the casing, the battery and even the printed circuit board itself. Also, the design of the antenna, that’s usually etched onto the printed circuit board, causes the transmission to vary depending on the direction.
Printed Circuit Board (PCB) Antenna
You can probably easily imagine how the above 2D design can lead to different radiation depending on whether you are viewing face on, sideways or end on.
In practice, it’s best to perform some tests to assess how the beacon radiation changes with beacon orientation. You can do this by measuring the change in RSSI (displayed in most apps) as you orientate the beacon.
For example, with the long 300m range iB003N-PA, we determined experimentally that the best range was when the non-battery face of the beacon was facing the observer.
iB003N-PA – Strongest signal for us was downwards in this photo
However, this was for our particular scenario. How and where the beacon is mounted can also affect transmission and hence range.
So, the next time you are testing the range or installing beacons, take some time to assess how the beacon orientation might be affecting the range.