Re: Network Manager GPRS support

[Dan Williams <dcbw redhat com>]

On Wed, 2008-07-30 at 17:37 +0100, Stuart Ward wrote:
> Dan
> 
> I see for the archives that you are working on the GSM support in
> Network Manager. I work for Hutchison UK (three network) and we are
> keen for better Linux support of mobile broadband modems. I Have
> access to a number of dongles and PCs with embedded cards, and can
> assist with some level of testing.

Great; most of the testing we need right now is making sure the modems
don't return horribly unexpected responses, and also making sure APNs
work the way we expect them to.

> As to the question on the current signal level received with at+csq
> this and many other commands are standardised in the 3GPP standard.
> 3GPP TS 27.007 AT command set for User Equipment (UE) available here:
> http://www.3gpp.org/ftp/Specs/html-info/27007.htm 

Right.  Tambet is working on some bits to add signal strength
indications.  However, we need to tag the various serial ports in HAL
before we can add that functionality.  Some modems have expose serial
ports, and thus we need to know which is the primary port (over which
PPP will be run) and which is the secondary port (which signal strength
can be acquired from while PPP is running on the primary port).  That
sort of thing.  We don't want to stuff a whole bunch of autodetection
logic into NetworkManager itself since HAL allows for that quite nicely.

Dan

> Here is the section on +CSQ:
> 
> Signal quality +CSQ
> Table 64: +CSQ action command syntax
> 
>                                Command
>                                    
>                                    
>                          Possible response(s)
>                                    
>                                    
>                                  +CSQ
>                                    
>                                    
>                           +CSQ: <rssi>,<ber>
>                                    
>                           +CME ERROR: <err>
>                                    
>                                    
>                                 +CSQ=?
>                                    
>                                    
>                        +CSQ: (list of supported
>                  <rssi>s),(list of supported <ber>s)
>                                    
>                                    
>  
> 
> Description
> 
> Execution command returns received signal strength indication <rssi>
> and channel bit error rate <ber> from the MT. Refer subclause 9.2 for
> possible <err> values.
> 
> Test command returns values supported as compound values.
> 
> Defined values
> 
> <rssi>:
> 
> 0    ‑113 dBm or less
> 
> 1    ‑111 dBm
> 
> 2...30 ‑109... ‑53 dBm
> 
> 31  ‑51 dBm or greater
> 
> 99  not known or not detectable
> 
> <ber> (in percent):
> 
> 0...7   as RXQUAL values in the table in TS 45.008 [20] subclause
> 8.2.4
> 
> 99  not known or not detectable
> 
> 
> As to the current dongles we mostly are using the Huawei models E220,
> E169 E169g  these work with the usb_modeswitch program. 
> Are you incorporating this functionality?
> 
> 
> 
> -- Stuart Ward M +44 7782325143
>