Arfcn calculation tool

[Philipp Fabian Benedikt Maier]

Hi Folks.

I always found it annoying to calculate the correspondending frequency
of an arfcn by hand or with the webbased arfcn calculator.

So i wrote a little program to do the work for me:
http://www.root.runningserver.com/web/runningserver/software/arfcncalc.tar

Maybe the one or other here on the list will find it useful.

regards.
Philipp

[dexter]

Hi Folks.

I always found it annoying to calculate the correspondending frequency
of an arfcn by hand or with the webbased arfcn calculator.

So i wrote a little program to do the work for me:
http://www.root.runningserver.com/web/runningserver/software/arfcncalc.tar

Maybe the one or other here on the list will find it useful.

regards.
Philipp

[Harald Welte]

Hi Dexter,

thanks for your program.

However, this problem had to be solved for OsmocomBB layer1 (and airprobe) already,
thus libosmocore already has (at least part of) the functionality, e.g. the
"uint16_t gsm_arfcn2freq10(uint16_t arfcn, int uplink)" function, which will
give you the frequency in units of 100kHz (to avoid floating point math).

The input parameter "arfcn" is the arfcn, optionally with the ARFCN_PCS bit
set, if you want PCS1900 instead of DCS1800.

Threre is also a function "enum gsm_band gsm_arfcn2band(uint16_t arfcn)"
which will tell you the band from the arfcn.

What is missing is the function to generate the ARFCN from the frequency.

Maybe you could submit a function with the protoctype like
"uint16_t gsm_freq10_to_arfcn(uint16_t freq10, int uplink)"
and submit it as a patch to libosmocore/src/gsm_utils.c

Next step would be to port your tool to use the functions of libosmocore
and then merge your tool into the openbsc source tree.

If that's too much effort I don't blame you... but I always try to avoid
code duplication when possible.

Regards,
Harald

[Harald Welte]

Oh, one more note: The information that yuo have in provider.h exists
as part of osmocom-bb/src/host/layer23/src/networks.c

We should move this into libosmocore, at that point you can also use it
from your tool or from other software.

Regards,
Harald

[Kevin]

You could also add the UARFCN defined in TS 25.104

Greetings,
Kevin

Post by Philipp Fabian Benedikt Maier
Hi Folks.
I always found it annoying to calculate the correspondending frequency
of an arfcn by hand or with the webbased arfcn calculator.
http://www.root.runningserver.com/web/runningserver/software/arfcncalc.tar
Maybe the one or other here on the list will find it useful.
regards.
Philipp