Possible to control the radio strength of a nanoBTS?

[Dieter Spaar]

Hello Harald,

On Wed, 3 Jun 2009 23:24:50 +0200, "Harald Welte" <laforge at gnumonks.org> wrote:
> 
> The BS-11 has 3W max output.

I think we have 2 Watt maximum, 3 Watt is the maximum for the 1800/1900
variant of the BS-11.

> That's quite obvious if you understand the details of the cell selection
> algorithm.  If you've been registered to an actual cell of the operator
> before, then that ARFCN/LAC is stored on the SIM card even when you shut
> off the phone.

Let me add a few more detail (I sent this to the list a while ago).
There are two EFs (Elementary Files) on the SIM which contain this
information:

  - EF_BCCH contains the cell allocation information from
    "SYSTEM INFORMATION 2".

  - EF_LOCI contains the TMSI, Location Update Timer, LAI and the
    status of the location update.

If those EFs are set to the correct values used by the test cell, the
phone will immediately look for the test cell when powered on and also
consider to be "registered" if no "IMSI Attach" is required.

> So yes, typically the translation of mcc/mnc happens in a table on the SIM
> card, and if that fails in a table that is included at compile time into the
> GSM firmware of the handset.

It seems that the mapping of MCC/MNC to names on the SIM was introduced
with GSM 31.102 (USIM for UMTS), GSM 11.11 did not have it. So it depends
on the SIM if it has this mapping. I looked at some phone firmware, in
this special case the mapping is done by looking at the SIM first (if it 
is an USIM), than at an optional table in the phone filesystem and finally
at the table in the firmware.

Best regards,
  Dieter
-- 
Dieter Spaar, Germany                           spaar at mirider.augusta.de