Opened 6 years ago

Closed 6 years ago

Last modified 6 years ago

#122 closed enhancement (fixed)

consider adding patch to reduce echo

Reported by: lindi Owned by: mickey
Priority: minor Milestone:
Component: framework/ogsmd Version:
Keywords: Cc: mail@…


Please consider adding equivalent of

to frameworkd.

Attachments (2) (592 bytes) - added by carllobo 6 years ago. (569 bytes) - added by carllobo 6 years ago.

Download all attachments as: .zip

Change History (8)

comment:1 Changed 6 years ago by mail@…

  • Cc mail@… added
  • Component changed from documentation to framework/ogsmd

Changing the component to gsmd. I’d like to see an offical patch for this, for inclusion in the Debian packages.

comment:2 Changed 6 years ago by mickey

  • Resolution set to fixed
  • Status changed from new to closed

comment:3 Changed 6 years ago by lindi

4619b9d748c5f21d6493b1bacc490934bbd0a62c added %N0187 but it does not seem to in 8b81d1bfa048fd7d13eca507bb9953be811f3940 anymore. I just noticed that if somebody calls me I need to do


before the call to totally get rid of echo. frameworkd currently send %N028B and %N0125 and only at init time. Where should I add commands that should be sent in init and after every call? I am using on debian but reading the source from git.

comment:4 Changed 6 years ago by mickey

Are you 110% sure that you really need to do this on every call? I'd like a second confirmation for that.

comment:5 Changed 6 years ago by lindi

Yes I am quite sure. Here's how I tested it:

1) I put fr to an empty room and set it to auto answer calls
2) I used cli-frameworkd to send
3) I went to another empty room and placed a call. There was buzz when I did not say anything since the gain was increased. However, when I talked and whistled to the phone I could not notice any echo.
4) I placed another call and the echo was clearly recognizable.
5) I sent gsmdebug.DebugCommand("AT%N0187\r\n") again
6) I placed another call and now the echo was gone again.

So it seems that %N0187 only affects one incoming call. Also if I restart fso-frameworkd and place a call I can still hear echo so the %N028B and %N0125 used by current frameworkd do not seem to do the same as %N0187.

comment:6 Changed 6 years ago by carllobo

I've been looking into this problem as well. From some research it seems that the %N0187 enables 12dB noise cancellation and the other 2 6dB. The 6dB seems to work with good call volume on most phones. There's some phones and conference equipment (which probably don't have inbuilt noise cancellation) where the echo comes in again. The 12dB works well on all phones, but the volume is low.
I'm attaching the two patches I'm using that seem to work. It sends the 12dB command and another command I found on a debian list I think that also appears to fix the call volume problem (it sets the call level to 230 in the modem).

Changed 6 years ago by carllobo

Changed 6 years ago by carllobo

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