Missing enum? "Get RF Band Information" (0x0031) / "Bandwidth List" (0x12) -> Value 9

[Reinhard Speyerer]

On Wed, Feb 19, 2025 at 12:20:00PM -0600, Dan Williams wrote:
> On Wed, 2025-02-19 at 18:38 +0100, Martin Maurer wrote:
> >  
> > Hi Dan,
> >  
> > this is perhaps interesting: The module is not yet
> > registering/working in the used network. 
> >  
> > The LED is still blinking every 2 seconds (time between the 2
> > seconds: LED dark).
> >  
> > (Side note: But I am also not yet able to take Quectel logs:
> >  
> > https://forums.quectel.com/t/catching-logs-from-rg255c-gl-with-qlog/44181
> >   )
> >  
> >  
> > It is a 5G RedCap module and perhaps module/network don't work yet
> > each other.
> 
> Yeah, I saw it was RedCap and thought maybe that was related (still
> could be) but then saw that the enum maxes out at 20MHz and there are
> more bandwidths than that from what I could tell.
> 

Hi Dan, hallo Martin,

according to what I see here with non RedCap devices, 9 means NR5G 20 Mhz
while NR5G 10 MHz would be 7. These values are consistent with the values from
https://git.codelinaro.org/clo/le/platform/vendor/qcom-opensource/snaptel-sdk .

This is another API and it actually uses NR5G_BW_NRB_20 instead of
NR5G_BW_MHZ_20 but some of its types are isomorphic to the corresponding
Gobi API types.

> > Not sure, what "Get RF Band Information" (0x0031) will then report?
> >  
> > There is no connection established by me, because not yet that far,
> > to do something like this.
> >  
> > Nevertheless I executed the suggested AT commands:
> >  
> > AT+QENG="servingcell"
> > +QENG: "servingcell","LIMSRV","NR5G-
> > SA","FDD",262,01,4F2872A01,328,7EAE,431070,1,1,-96,-11,5,0,27
> 
> We care about the "1,1" here, which means band n1 and 10MHz bandwidth.
> So maybe 9 means RedCap 10Mhz? But we can't know for sure.
> 
> If you're able to get it to register with the network, could you redo
> this test and see if the values from +QENG change?
> 

The problems with the Quectel RG255-GL and the Telekom 5G SA network also
occur with a Fibocom FG132-GL when I set the device to 5G SA only mode.

NASGetSystemInfo only returns ServiceStatus PowerSaveOrDeepSleep
while both NASGetRFInfo and at+gtccinfo? return a n1 20MHz cell:
  NASGetRFInfo 3000
  +OK NASGetRFInfo 02040000000000010600010cfa00de93110800010cfa00de930600120600010c09000000
  at+gtccinfo?
  +GTCCINFO:
  NR service cell:
  1,9,262,01,<TAC>,<CI1>,693DE,<PCI1>,501,20,3,65,65,63

The only workaround to make the FG132-GL register to the Telekom 5G SA network
I found after some experimentation is to disable 5G SA band n1 after which it
registers on a n28 10MHz cell in the Telekom 5G SA network including IMS
registration:
  NASGetRFInfo 3000
  +OK NASGetRFInfo 02040000000000010600010c0101ca5b110800010c0101ca5b0200120600010c07000000
  at+gtccinfo?
  +GTCCINFO:
  NR service cell:
  1,9,262,01,<TAC>,<CI2>,25BCA,<PCI2>,5028,10,3,61,61,61
  at+cops?
  +COPS: 1,0,"DTAG",11
  OK
  at+cavims?
  +CAVIMS: 1
  OK

This looks like a firmware bug with current Qualcomm SDX35 firmwares to me.

Regards,
Reinhard