In this article, you'll learn about best practices when setting the Transmission Power for your beacons.
The basic configuration settings for beacons include:
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RF Transmission Power: TX Power Level for all packets
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Advertising Interval: how often beacons push out a signal
The settings you choose for Transmission Power and Interval have a great impact on how your beacon network operates. Therefore, choosing the most practical and efficient settings is greatly determined by your specific needs and use case.
We'll focus on Transmission Power only - there are a number of factors to consider when choosing the optimal TX Power setting for your application use.
The major things the above settings affect include:
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Signal range - greatly influenced by TX Power
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Signal stability - somewhat influenced by TX Power, but more so by Interval
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Battery life - somewhat influenced by TX Power, but more so by Interval
Now, it may be easy to say “I want the best of all three”, but this is not always possible or even really necessary. The keyword here is efficiency and practicality, using too much or too little power can greatly affect the effectiveness of your beacon deployment. Let’s go over the particulars.
The Transmission Power setting determines how powerful the signal will be transmitted by the beacon. This is measured in dBm (Decibel-milliwatts) and corresponds to a number rating from 0 to 7; 0 is least powerful and 7 is most powerful.
As you might expect, if you make the transmission more powerful, you'll increase the range of the signal. However, it's also true that the more powerful the transmission the bigger the energy drain and accordingly the shorter battery life.
The table below shows how the TX Power setting affects a beacon’s range and battery life.
|
TX Power (device configuration) |
Transmission Power |
Expected range |
Estimated Battery Life* |
|---|---|---|---|
|
1 |
-20 dBm |
13 ft (4 m) |
Up to 52 months |
|
3** |
-12 dBm |
65 ft (20 m) |
Up to 50 months |
|
7 |
4 dBm |
230 ft (70 m) |
Up to 35 months |
* Assuming an interval of 350ms and optimal environmental conditions.
** Kontakt.io default TX Power setting on some beacon models.
For additional details, see Beacon transmission power, range, and RSSI.
The best way to determine the best TX Power for your needs is to answer the following questions:
For example, you may want to use the max TX Power for beacons placed at a venue entrance to send a welcome message or other push notifications. This is because you likely want as many people connecting with this beacon as possible, therefore you are willing to sacrifice battery life to gain the widest range possible.
Then you may have beacons attached to a specific item, say an exhibit or shelf, where you only want to connect to people who are standing directly in front of said item. In this case, you certainly want to use a lower TX Power to conserve battery life and still achieve the same expected results (i.e. sending relevant information about that specific item).
This is a question of cost vs. convenience vs. efficiency. Maybe you are perfectly willing to change batteries every month or perhaps you vastly prefer getting a few years out of each battery.
Since you can configure beacons individually, it's also pretty simple to get the “best of both worlds”. For example, having a few entry/exit beacons with max TX Power and then having the rest of your fleet use a lower setting to extend their battery life.
Keep in mind however that to maximize the value you get out of beacons, you may end up having to replace beacon batteries more often than you may prefer. It’s just good business sense – a little bit of bother to gain a lot of profit.
This is a question of intended use. According to customer feedback, these are some of the common reasons our customers are using the maximum power setting:
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It's important that this beacon can be found by as many people as possible. For example, to identify a landmark or mark a meeting point.
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It's important that visitors that are more than 16 feet (5 meters) away don’t miss the message attached to this beacon. For example, marking an entry or exit from a zone or helping someone find their seat.
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There is a high level of potential interference in the immediate vicinity of this particular beacon, so you need a powerful signal to cut through the interference. For example, many solid dense objects surround the beacon, and yes, people count as “dense heavy objects”.
If the above situations do not apply to you, then you can likely get away with a lower TX Power level. This will help save battery and overall make your system operation more efficient.
To get the best performance with the lowest possible TX Power setting or widest possible signal coverage without unnecessarily wasting battery life.
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If you need the signal range to be as wide as possible in a high-traffic area, use the max TX Power setting and install the beacon roughly 9 feet (3 meters) up from the floor to reduce interference from people walking by.
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If you only need the beacon to be detected a few meters / several feet away. For example to identify a product sitting on a shelf, use a lower TX Power setting.
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Always be mindful of “line-of-sight" - there are no objects in between a beacon and the customer’s smart device.
If getting “line-of-sight” is impossible or impractical, try to make sure these objects are not too heavy or dense. For example, thick steel panels or brick walls between a beacon and a smart device.
Tip
Since beacons can have their TX Power configured individually, it is easy to mix and match beacons with different TX Power settings. This enables you to assign an optimal value to each beacon based on the intended use of that beacon, which allows you to maximize efficiency as appropriate.