After playing with it a bit I found out: current Gammu support for this phone is not working at all. After some looking at sources I decided to do implementation same way as in Alcatel - overlay driver which will use AT functions if they can be used. If you're interested in testing, my code will grow in my arch repository (more information on http://cihar.com/gammu), I'm going to submit it to upstream once there will be completed some set of functionality.