Low Wi-Fi download speed while Bluetooth streaming

[lpryszcz]

Hi, the Wi-Fi download speed drop to 1-2 MBps when Bluetooth is connected and streaming, while upload speeds are OK :

• https://www.speedtest.net/result/9248204484
• https://www.speedtest.net/result/9248260979

The download speeds are OK (~30-40 Mbps) when I disable or while I'm at least not streaming anything through Bluetooth adapter (the device can be paired):

• https://www.speedtest.net/result/9248254110
• https://www.speedtest.net/result/9245552014

Does anyone known why this issue exists?

I've tried both, official Ubuntu version of rtl8821ce module (5.5.2.1) and the latest version available from here (5.5.2.2). My kernel is 5.3.0-46-generic (x86_64).

It's cross post from https://unix.stackexchange.com/a/578422/32825

[tomaspinho]

Have you tried moving your access point to another channel? BlueTooth and Wi-Fi share the same frequency band (2.4GHz) and it's not rare to find them both causing interference on each other. May be unrelated to this driver.

[lpryszcz]

Good hint, nevertheless it was channel 6, I've changed it to 13 and the same problem persists.

Apparently it could be due to Bluetooth frequency hopping (dynamic allocation of frequency), so I've tried to disable it (sudo bccmd -d hci0 singlechan 2) but unfortunately my device is not supported. Interestingly, my phone doesn't cause the same interference even when placed on the laptop.

Because BT and WiFi frequencies are completely overlapping I'm afraid there is not much I can do.

[lr1729]

Also having this issue, wifi slows to < 1 Mb/s with a headset connected in the 5.4 kernel