When a user will move from 3G to 2G network then all the service supported on Grameenphone 3G network like video call, high speed internet access, etc will not be available, the user will get all basic 2G service like what he gets now. The mobility will be seamless but as you move out of 3G coverage area you will fall back on 2G coverage without disrupting your data or voice session. However in case of data the speeds will also fall back to 2G speeds.