[PROBLEM] Losing Wifi Connection

[TamedShrew]

Hello,
I have a problem with browser connection dropping and not coming back. I've tried trawling these forums but can't find a solution.

When I plug in an ethernet cable I can make a UI connection again. This allows me to reboot and then things work fine again (for a while).

Rebooting the wifi router will bring things back.

Sometimes it'll work for several days, other times a couple of hours. It sometimes loses connection whilst playing music.

I have moode on a RPI 3 and RPI 4 both playing music from a local storage through a USB DAC.

When connection is lost the router still thinks that they are connected.

The wifi strength is good. I don't have any problems with any other devices connection (phones, consoles, laptops etc.)

Unfortunately I cannot make a permanent ethernet connection. I am thinking of going down the touch screen route, but I would rather avoid it.

If anyone has any suggestions then I'd be very grateful.

[Tim Curtis]

Are your Pi's in metal enclosures?

Post the moOde start log.

Code:

moodeutl -l

[TamedShrew]

Are your Pi's in metal enclosures?

Post the moOde start log.

Code:

moodeutl -l

Thanks for getting back to me.

Good point. They are in metal enclosures. I'll try removing them later to see if that makes any difference.

re: start log
I assume this is using SSH (I've not had much experience with linux). Is there a guide somewhere giving the password?

[TamedShrew]

Are your Pi's in metal enclosures?

Post the moOde start log.

Code:

moodeutl -l

Thanks for getting back to me.

Good point. They are in metal enclosures. I'll try removing them later to see if that makes any difference.

re: start log
I assume this is using SSH (I've not had much experience with linux). Is there a guide somewhere giving the password?

I've just tried putting a usb wifi dongle in one of them and it's sprung back to life. A good sign I hope!

[Tim Curtis]

If the Pi's are in metal enclosures the signals from their integrated WiFi/Bluetooth adapters will be heavily attenuated by the metal and thus lots of WiFi issues will occur including no signal, intermittent signal, poor performance, etc.

No need to post the startup log but for future reference some helpful links are below.

Setup Guide on GitHub
https://github.com/moode-player/moode/bl.../setup.txt

In the Player
- Menu, Configure, System
- Menu, About
- View Setup guide

SSH terminal
- Menu, Configure, System
- SSH term server ON
- OPEN Web SSH terminal
- User: Pi
- Password: moodeaudio

[TamedShrew]

If the Pi's are in metal enclosures the signals from their integrated WiFi/Bluetooth adapters will be heavily attenuated by the metal and thus lots of WiFi issues will occur including no signal, intermittent signal, poor performance, etc.

No need to post the startup log but for future reference some helpful links are below.

Setup Guide on GitHub
https://github.com/moode-player/moode/bl.../setup.txt

In the Player
- Menu, Configure, System
- Menu, About
- View Setup guide

SSH terminal
- Menu, Configure, System
- SSH term server ON
- OPEN Web SSH terminal
- User: Pi
- Password: moodeaudio

Thank you so much, Tim.
I'll see how it goes with the dongle for a while and then if that solves things buy a plastic case.

[Tim Curtis]

Btw, what model WiFi dongle are you using?

I've been looking for good alternatives to Comfast CF-912AC which is very hard to get these days.

[TamedShrew]

Btw, what model WiFi dongle are you using?

I've been looking for good alternatives to Comfast CF-912AC which is very hard to get these days.

I plugged one of these in, that I found at the bottom of my old PC junk box.
Edimax EW-7811UN v1 probably impossible to get hold of these days. There's a v2 with awful reviews!

Unfortunately it's not fixed the problem. Nor has removing it from the case entirely.
Might have to start thinking about routing some ethernet cables around the house!

[TheOldPresbyope]

@TamedShrew

Your last remark "Nor has removing it from the case entirely" suggests the problem may not lie entirely in signal strength, but there are a few measures of the quality of the connection which can help.

From the command line of the player, you can run the following command

Code:

iwconfig

#or if you're sure that wlan0 is the WiFi interface

iwconfig wlan0

For example, here is the output from one of my players

Code:

pi@CM4:~ $ iwconfig
eth0      no wireless extensions.

wlan0     IEEE 802.11  ESSID:"Krypton"  
         Mode:Managed  Frequency:5.22 GHz  Access Point: A8:70:5D:49:74:BA  
         Bit Rate=433.3 Mb/s   Tx-Power=31 dBm  
         Retry short limit:7   RTS thr:off   Fragment thr:off
         Power Management:on
         Link Quality=66/70  Signal level=-44 dBm  
         Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
         Tx excessive retries:15  Invalid misc:0   Missed beacon:0

lo        no wireless extensions.

The link quality and signal level numbers are the first to look at. 

A lower link quality fraction suggests poorer performance.

Similarly, a lower signal level suggests the likelihood of poorer performance. Note that dBm (decibel-milliwatt) numbers run from 0 to -100 with 0 the highest and -100 essentially nonexistent. Tthis is a logarithmic scale so a change of 10dBm represents a factor of 10 change in power.

A typical rule of thumb I grabbed from somebody's blog is:

• -30 to -50dBm  – Excellent signal strength (Next to Router)
  
• -50 to -67dBM  – At Good signal strength for Web browsing, voice/video calls.
  
• -67 to -70dBM  – Best effort for Web browsing for reliable packet delivery.
  
• -70 to -80dbm  – Experience bad connectivity, Packet delivery may be unreliable.
  
• -90 to 100dBm – Worst signal strength.
  

And, yes, my example player is just across the room from my access point.

High numbers of retries and "invalids" also suggest poor performance.

Apart from signal strength, there's the question of radio frequency interference. The presence of multiple WiFi  sources can be a problem; so is using the 2.4GHz band because so many WiFi devices use it, because it's shared with Bluetooth devices, and because it's so close to the ISM band---think microwave ranges, for example.

Regards,
Kent

Footnotes:

• There are other Linux tools available which can slice and dice the data in more detail but I find this use of iwconf to be adequate for quick checks.
  
• It's common to see some variation in the signal strength measures for different WiFi adapters in the same equipment and location, but they generally agree. You'd think vendors would have this sorted in their firmware. Think again.
  

[TamedShrew]

@TamedShrew

Your last remark "Nor has removing it from the case entirely" suggests the problem may not lie entirely in signal strength, but there are a few measures of the quality of the connection which can help.

From the command line of the player, you can run the following command

Code:

iwconfig

#or if you're sure that wlan0 is the WiFi interface

iwconfig wlan0

For example, here is the output from one of my players

Code:

pi@CM4:~ $ iwconfig
eth0      no wireless extensions.

wlan0     IEEE 802.11  ESSID:"Krypton"  
         Mode:Managed  Frequency:5.22 GHz  Access Point: A8:70:5D:49:74:BA  
         Bit Rate=433.3 Mb/s   Tx-Power=31 dBm  
         Retry short limit:7   RTS thr:off   Fragment thr:off
         Power Management:on
         Link Quality=66/70  Signal level=-44 dBm  
         Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
         Tx excessive retries:15  Invalid misc:0   Missed beacon:0

lo        no wireless extensions.

The link quality and signal level numbers are the first to look at. 

A lower link quality fraction suggests poorer performance.

Similarly, a lower signal level suggests the likelihood of poorer performance. Note that dBm (decibel-milliwatt) numbers run from 0 to -100 with 0 the highest and -100 essentially nonexistent. Tthis is a logarithmic scale so a change of 10dBm represents a factor of 10 change in power.

A typical rule of thumb I grabbed from somebody's blog is:

• -30 to -50dBm  – Excellent signal strength (Next to Router)
  
• -50 to -67dBM  – At Good signal strength for Web browsing, voice/video calls.
  
• -67 to -70dBM  – Best effort for Web browsing for reliable packet delivery.
  
• -70 to -80dbm  – Experience bad connectivity, Packet delivery may be unreliable.
  
• -90 to 100dBm – Worst signal strength.
  

And, yes, my example player is just across the room from my access point.

High numbers of retries and "invalids" also suggest poor performance.

Apart from signal strength, there's the question of radio frequency interference. The presence of multiple WiFi  sources can be a problem; so is using the 2.4GHz band because so many WiFi devices use it, because it's shared with Bluetooth devices, and because it's so close to the ISM band---think microwave ranges, for example.

Regards,
Kent

Footnotes:

• There are other Linux tools available which can slice and dice the data in more detail but I find this use of iwconf to be adequate for quick checks.
  
• It's common to see some variation in the signal strength measures for different WiFi adapters in the same equipment and location, but they generally agree. You'd think vendors would have this sorted in their firmware. Think again.
  

Thanks Kent @TheOldPresbyope very educational! I've done some tests and things aren't as good as I initially thought. Most of the time it's at -60dBM, but every so often it nose dives to -70dBM. I'd assumed that because we seem to stream films and our son plays online games without any hiccoughs it was good but there must be a lot of buffering going on.
I'm going to connect them all up with ethernet (as the player that I've temporarily wired in has no problems). Just got to convince my partner that it's ok to take up some floor boards!
Cheers,
Nick