f0 is currently set to arfcns[0] in range_enc_determine_range(),
while GSM 04.08 requires f0 to be ARFCN 0 in range1024 encoding.
This patch modifies range_enc_determine_range() to force f0 to be 0
if this encoding is used. This way the case distinction in
range_enc_filter_arfcns() is not longer necessary.
Sponsored-by: On-Waves ehf
I saw the old copy of the "Appendix J" code too late and I have
discovered some quirks and I am more familar with my implementation.
Most noticable 'w' only needs to be as big as the input arfcn but
requires the 'w' to be initialized. The power_of_2 implementation
differs as well (mine matches the output of wirehsark).
The f0 could be chosen in a better way but right now picking
the lower bound is the easiest. It is not clear if to use
modulo if the range is chosen in the middle. This can be improved
in the future. Right now I have no bit fiddling for range128, 256
and 1024 as I was running out of time.
Jacob Erlbeck