Beacon Tx power and transmission range

[davidz]

I have set up a Beacon with nrf52840 and SDK 17. The Beacon signal is transmitted in 10s interval. The Beacon transmitter does not need to receive any response data. The default Tx power of the Beacon signal is 0dbm. When I increased the Tx power to 8dbm, I checked the Beacon signal strength with an Iphone and nrf Connect app. I found that increasing the Tx power to 8dbm has almost no effect on the receive signal strength measured by the nrf Connect App of the Iphone. 

So I am curious that:

1. If I increase the Beacon Tx power to 8dbm, will it increase the Beacon coverage distance? 

2. If I use another nrf52840 with a strong antenna as a receiver (the claimed range is more than 1km), will this long distance receiver increase the receive range? Or the Beacon signal coverage has nothing to do with the receiver?

Thank you in advance:)

[Jørgen Holmefjord]

Hi,

1. In general, increased TX output power will give better coverage if all other parameters are kept constant. If the transmitter and receiver are very close to each others, you may not see a large difference in the received signal strength. The range will depend on many factors, including output power, receiver sensitivity, environment, noise, etc. You can have a look at the range estimator from Bluetooth SIG, where you can input your parameters to get an estimate.
2. If the receiver has an antenna with better receive gain, it may increase its own ability to receive packets from the beacon at a larger area.

One of our FAEs posted some results from his own range testing with different output powers and radio modes in this blog post.

Best regards,
Jørgen

[davidz]

This is great information. Thanks so much for your help!