[Nexus 4 Q&A, Help & Troubleshooting] Vioner:
Hi,

I'm experiencing annoying WiFi/Blueooth problems and I need your input on this one.

This is a very common one that has been present since the beginning of N4's life, but isn't present in all Android builds. I haven't found any nice, neat thread with proper info and description of the problem, so I'm posting one myself.

Specifics of the WiFi + Bluetooth problem are:

1. Bluetooth is ON, mouse and keyboard connected.

2. Wifi is ON, connected to a 2.4GH AP and being used.

3. After a very short period of time (mostly from 20-60s, sometimes upto 3minutes) the WiFi is still connected, but internet connection drops - pinging or opening a new browser page won't get the connection back.

4. Restarting WiFi gets internet back, but just for as long as in .3

5. If I turn one of the bluetooth devices off, internet immediately comes back online, but only like in .3

6. When Bluetooth is on with no devices connected everything is fine.

7. Turning Bluetooth on and connecting devices first, then Wifi doesn't make a difference (some poeple say this helps).

8. Router and bluetooth devices DO NOT matter and im am 100% sure of that - tested them with Note II with no problems.

This is obviously interference, but Nexus software/driver is bugged and won't handle this interference - won't reestablish connection when it's dropped (timeout).

My Nexus 4 info:

Android version: 5.1.1

Builds with the issue: CM12.1-20150829-nightly-mako / Euphoria-OS 1.1 (AUG 15) and previous Euphoria OS builds.

There are few apps that might be a workaround for this issue. They monitor the connection and reestablish it whenever it drops.

I've tested the Wifi Fixer app and it does work for me. So this is one of efficient workarounds, but still using internet is annoying as there are few seconds breaks in service at least once every 3mins, but mostly every 20-60secs.

LOGCAT:

I was just running continuos ICMP pinging and staring at the latency output while adb logcat was running on PC.

Suddenly, without any reason I could think of, connection got dropped and host become unreachable. I tried to reproduce this occurence, but unfortunetly it's "random" and appears without any apparent reason.

D/HeadsetStateMachine(21494): Disconnected process message: 10, size: 0
D/audio_hw_primary(191): disable_audio_route: reset and update mixer path: low-latency-playback
D/audio_hw_primary(191): disable_snd_device: snd_device(2: speaker)
E/WifiStateMachine(633): WifiStateMachine CMD_START_SCAN source -2 txSuccessRate=3.63 rxSuccessRate=4.05 targetRoamBSSID=any RSSI=-50
D/HeadsetStateMachine(21494): Disconnected process message: 10, size: 0

WIFI BAND:

Can't detect or connect to my 5GHz SSID while I'm connected to bluetooth devices.

Even if I connect to a 5GHz AP first and then switch BT on, the network will drop internet connection shortly or whole Wifi connection will drop (unlike with 2.4GHz).

I can test few ROMs, but it'd be better if I knew which specifically could work. Don't wanna waste time. I want to focus latest builds obviously - interested in Lollipop only.

So if you've came across this problem and somehow got it fixed then please share a solution.