Re: 3G Signal CSQ

[Aleksander Morgado <aleksander lanedo com>]

> > That's 1/2 a lie, they support RSSI, which is the value they return from
> > AT+CSQ.  RSSI is an arbitrary unit that's assumed to be linear in scale
> > (unlike dBm).  CSQ is defined to be 0 - 31, and internally in NM that's
> > normalized to a 0...100 scale.  Technically GetSignalQuality*does*
> > return RSSI, but may not be reported in the modem's native RSSI scale.
> > On some devices (Ericsson MBM) the scale is 0...5 even.
> >
> > If you're looking for a much deeper RSSI, like radio diagnostic data,
> > then that's actually impossible to get for most devices
>
> Very thanks for your help.
>
> Aleksander already said me (in spanish). But with my modem seems to be a
> bug with "echo", solved in next versions of NM (fedora 16 still have old
> version).

Specifically, the logs show that even if we try to disable the echo, the 
modem doesn't do it, so the replies to AT+CSQ and every other command 
come with the echo:

modem-manager[2430]:<debug>  [1332115236.128042] 
[mm-at-serial-port.c:298] debug_log(): (ttyACM1): -->  'AT+CSQ<CR>'
modem-manager[2430]:<debug>  [1332115236.134616] 
[mm-at-serial-port.c:298] debug_log(): (ttyACM1):<-- 'AT+CSQ'
modem-manager[2430]:<debug>  [1332115236.136292] 
[mm-at-serial-port.c:298] debug_log(): (ttyACM1):<-- '<CR><CR><LF>+CSQ: 
24,0<CR><LF><CR><LF>OK<CR><LF>'

Newer MM 0.5.2 comes with the built-in echo removal thingy, which should 
help to fix this issue.

--
Aleksander