Ability to run GSM network on any frequency
No issues for this version
Since OsmocomBB does support SDR PHY now, the working frequency range is only limited by hardware capabilities. In other words, the "ARFCN -> frequency" calculation may be modified to add a constant frequency offset, so this will allow one to run both base stations and (OsmocomBB-based) mobile stations on any frequency (e.g. in 2.4 GHz WiFi band)!
Of course, regular GSM phones are not able to "see" any networks outside the known predefined ranges (e.g. GSM-900, DCS-1800), so they wouldn't be able to camp to a network running on some shifted frequency. But we believe that this feature can be helpful for research and development.
Update from 17.01.2019¶
The gr-gsm based transceiver, grgsm_trx, now has --freq-offset command line option, that allows to shift the baseband frequency. In order to shift the baseband frequency of the network side, OsmoTRX needs to be hacked a bit. This feature isn't merged to the master so far, please check out https://git.osmocom.org/osmo-trx/log/?h=fixeria/freq_shift.