Testing the long range feature of nRF52833 chip

[Roland]

Dear Nordic，

We developed a product based on the nRF52833 chip, with an external antenna, 3dBi gain.  Use a smartphone to scan the product in the outdoor，the transmission distance I got for 8 dBm TX power and interval 100ms on 1M PHY was 185 meters. I want ask that How long the distance can nrf52833 transmit upto 8 dBm TX power and interval 100ms in an open and unobstructed and non interference environment?  We want to compare the transmission distance which is very helpful for us to improve the product.

It'd be really great to get some help with this, thanks

[Simonr]

Hi

You should be able to reach much longer distances if you use the Coded PHY (long range mode) instead of the 1M PHY, but please note that the data rate will be ~8 times lower, and that a lot of phones still don't support Coded PHY.

Please check out our test of the Coded PHY conducted by one of my colleagues here. Using a Development Kit you should be able to reach ~1300 meters in Coded PHY mode at 0dBm. We have not tested this at 8dBm ourselves, but it is described how to do so.

Best regards,

Simon

[Roland]

We tested with  nRF52840 Rev C(PCA10056 v0.12.0 PDK).The distance I got for 1M PHY 0 dBm TX was 724 meters，and 

the scanner logs show that we can get adv packets with a signal strength of around -93 dBm.

The distance I got for Coded PHY 0 dBm TX was 740 meters，and the scanner logs show that we can get adv packets with a signal strength of around -94 dBm. We didn't reach much longer distances (outdoors)  using the Coded PHY (long range mode) instead of the 1M PHY.

What factors cause our Coded PHY test results to differ greatly from yours?

[Simonr]

Hi Roland

Are you sure you have enabled Coded PHY on the scanner and advertising device? With this (almost insignificant) increase in range, it doesn't sound to me like Coded PHY is enabled, can you upload a code snippet of how you initialize advertising and scanning in your applications?

If you do in fact use Coded PHY but still only see this tiny increase in range, here are a few reasons for this:

• Your test environment is more noisy at >700m.
• The custom board is not able to transmit longer than this for some reason. Not optimal antenna tuning or the application is not transmitting messages on the Coded PHY optimally.
• Weather conditions during testing (rain/snow will decrease range considerably)

Best regards,

Simon