Category: Power

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.

iBeacon Measured power setting

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 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)

USB Beacons for Fixed Installations

Beacons are often placed in shops, offices and other buildings for detection in smartphone apps. Battery powered beacons last from months to years depending on the size of the battery and the transmission power (adjustable). The compromise between battery life and physical range can be avoided if USB beacons are used instead.

USB beacons are powered from an available wallsocket, laptop, desktop or other standard USB socket. Alternatively, they can be powered using an inexpensive mains charger used to charge a smartphone or other device. Powering from the mains allows the beacon to be permanently set to full power with no worry about checking or changing the battery.

The use of mains power also allows for use of specialist beacons that output the maximium legally allowed (Class 1) power that wouldn’t be feasible using battery power.

The FSC-BP109 can be received up to 1000m on Android and 4000m on iOS.

View USB beacons

New Beacon Power Measurement Service

Since our original post on power measurement in 2016, we have been occasionally providing power measurement services as part of consultancy. Last week we started offering it as separate service orderable via our web store.

Our in-house designed power analyser

We take a beacon the same as yours, or one you send to us, and measure the actual power use with your specific settings.

Note, however, that if you will be using batteries that have been included with beacons, those batteries will have been used for an indeterminate time in the factory for soak testing the beacon. You will need to use new batteries to obtain the maximum battery life.

What’s the Affect of Changing the Power on the iB003N-PA?

The iB003N-PA has a range up to 300m because it uses the RFAXIS X2401C 2.4GHz amplifier to increase the range.

iB003N-PA

When you use the manufacturer app to change the power output by a beacon, you are changing the power output by the Nordic nRF51 System on a Chip (SoC) that is usually fed to the antenna. In the case of the iB003N-PA, the RFAXIS X2401C instead receives the signal, amplifies it and sends it to the antenna. The resultant change in output is:

SoC Setting X2401C Output
0dbm 20dBm
4dbm 20dBm
-5dbm 15dBm
-10dbm 10dBm

20dBm is the maximum allowable output for class 1 Bluetooth. There’s no difference whether you set to 0dBm or 4dBm, the output will be 20dBm. Even at a low power setting, -10dbm, the amplified output is 10dBm which is relatively high compared to the nominal 0dBm for most beacons. That’s just over 3x the power (3dBm change is a doubling of power) of a normal beacon. You can see that this beacon is primarily designed for long distance and there’s no need to change the SoC power from the default 0dBm = 20dBm.

View our ultra long range beacons

New Long Range 210L Beacon

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.

View our ultra-long range beacons