PHY coded and Coexistence

[damien5606]

Hello,

I'm testing PHY coding (for long range), I'm pretty surprise from what I get when I scan the RSSI of bluetooth channels (with Nordic app).

This is my set up:

M1 is the central, S1 is the peripheral sending 1ko/s. (with uart exemple) I use softdevice 140 V5 alpha.2

M3 is the RSSI scanner connected to "Nordic app RSSI Viewer" Here are the results I get for phy= 1mbps (Short Range) and for phy=125kbps (coded-Long Range):

1. Short Range
2. Long Range

Can you explain me why the long Range mode trash all Bluetooth channels ? this is one link (S1-M1) so my data received is what I expected (1ko/s) but when I use 10 links, the data rate drops dramatically.

Regards,

-Damien

[damien5606]

(1/2) Yes, I'm using the same CI on those tests. MSEC_TO_UNITS(10, UNIT_1_25_MS) for uart_app. (For all the tests I've done with those pictures) When PHY is coded (bottom picture), the data is staying 8x longer in the air that's might be why I see a RSSI stronger signal (than the short range, top picture).

But I've an other project, base on the nrf52832 chip with a 5kBytes/s data rate (at PHY 1Mbps) with the same CI, So I guess It should corresponds to 625Bytes/s in coded phy if you compare on-air time and It's not that far from the 1000Bytes/s data rate from the bottom picture. And I don't see any RSSI activities like the one I see here on long range.

I understand that my RSSI viewer set-up do kind of an averaging and maybe there's only one active channel at a the same time so the boards shouldn't disturb each others.