SDR PHY summer status update!
During this summer we have been working on the project, and despite the lack of time (daily job, traveling, etc.), some important features were introduced, so we are happy to highlight them.
First of all, the project has it's own wiki now, as well as a separate bug/feature tracker. For a long time, there was only a single page with brief description within the OsmocomBB project wiki. Having a dedicated project in Redmine, we are able to provide well structured description and documentation for our milestones. Kudos to Harald Welte!
A few weeks ago, the first milestone has been completed - "Ability to run GSM network on any frequency"! We have managed to run a GSM network in 2.4 GHz WiFi band, connect an SDR-based phone and successfully tested the regular subscriber's activity, such as SMS messaging and voice calls. More details about this feature will be shared soon.
There was a lot of work at the front of audio integration (see https://osmocom.org/versions/133). TCH/H channel coding implementation (see https://osmocom.org/issues/3419) in trxcon has been sent for review. In addition to Full Rate (GSM FR codec) speech, both HR (Half Rate) and EFR (Enhanced Full Rate) codecs are supported as well now! At the moment, all changes related to audio support in OsmocomBB can be found in a separate branch: https://git.osmocom.org/osmocom-bb/log/?h=fixeria/audio
Work on frequency hopping is also ongoing. Up to this point we used OsmoTRX for the purpose of testing of new features in the real world. As OsmoTRX currently doesn't support frequency hopping, we needed to find something else to test this functionality. For this purpose we hooked our mobile station to a Racal 6103E tester (kudos to Sylvain Munaut) that has support for frequency hopping, and currently it is possible to perform location registration and assignment of a traffic channel with it.