Long range coexistence

[damien5606]

Hello,

We'd like to connect 50 bluetooth 5 devices (nRF52840) to a Receiver (made of multiple centrals nRF52840) with a long range (PHY 250kbps, conn interval 50ms, no dle, ATT_MTU 23)

As I understood there're 37 bluetooth channels + 3 for advertising. If I assume that a nRF52840 central can be connected at 5 nRF52840 peripheral at the same time (I guess on the same bluetooth channel), I would need 10 nrf52840 centrals in my receiver to connect all my devices. So I'd use 10 channels.

Do you think they will interfere with eachother (knowing we'll work with long distance signal so very weak ones) or the space between the channel is big enough ?

Thank you a lot,

-Damien

[MartinBL]

The main files in your link seem to be compiled with S140 v5 alpha which has a known bug that possibly affects throughput on long range. You say that you can see the same on S140 v6 alpha though, so can you share the code you used for that too? As I mentioned in my edit above I'm not able to reproduce it with S140 v6 alpha, so maybe the issue is in your application.

[damien5606]

Martin,

When I tested with S140 v6, it was with the ble_app_att_mtu_throughput example. I'd like to test it with a uart_example (because I'm more familiar about how it works) provided with SDK v14 but unfortunately it seems they're only compatible with S140 v5.2 and I've trouble understanding the SDK migration guide S140 v5.2 to S140 v5.3, and it seems there's not migration guide from s140 v5.3 to v6.

I'll test again with the ble_app_att_mtu_throughput example S140v6, power 9dBm, and send you the results soon, in the meantime, do you have any idea when'd be the release date for a new SDK compatible s140v6 ?

Thank you for your time. -Damien

[MartinBL]

No, unfortunately there is no migration guide for S140 6 alpha (there are usually no migration guide or specification for alpha releases), but I suppose you have seen the readme.md file and sdk_patch.diff file that comes with the download? They help you migrate the throughput example, but migrating all the other BLE examples in the SDK is still a pain. Anyway, as far as I know SDK 15 will be released when the S140 is in production version, and the S140 production version will be released when the nRF52840 SoC goes to production version sometime in Q1 next year.