Other Parts Discussed in Thread: WL1837
We are experiencing a WiFi co-existence issue between 5GHz and 2.4GHz usage of WL1837MOD. More specifically, simply making a 2.4GHz WiFi connection adversely affects the latency of a RTP stream being passed via the 5GHz WiFi. Making a 2.4GHz BT audio connection does NOT cause the issue.
Our system consist of two identical units with:
- Beaglebone Black + Element14 WL Gateway cape with WL1837
- TI SDK 05_01_00_11 with Enable-TI-WiFi-Bluetooth-am335x-boneblack-WL1837.patch ( link to patch obtained from TI E2E forum post )
- arago-base-tisdk-image with packagegroup-arago-tisdk-connectivity
One unit acts as a 5GHz AP, the other a 5GHz STN. We use the scripts in /usr/share/wl18xx to start the AP, the station, and make the connection. We modified hostapd.conf to use mode a and channel 40 so the connection is made over 5 GHz. This is all working fine, and we achieve good throughput, and the CPU idle % for both units is over 50%. We have a simulated application streaming data from the STN to the AP, and we are able to measure the latency of the stream. We get around 20 ms, with a little jitter, and this is acceptable to us.
When the AP is additionally used "multi-role" as a STN connecting to our office LAN (or other non-secure APs), the latency jitter increases, often jumping to over 100ms. When 2.4GHz traffic is added the frequency and intensity of the latency issues gets even worse. CPU idle time is barely affected by the increased activity, so we do not believe this to be a CPU loading issue. We are currently building an "RT" version of the kernel just to test if that helps. However, at this time we believe this to more likely be a WL1837 firmware issue.
Are there any wlconf parameters we can experiment with that might affect this issue? Any diagnostics for the WL1837 module we can use to troubleshoot this?
Thanks,
Mark Wattier
EQware Engineering, Inc.
