using BTSAP from layer23

hi, i am current writing the sim client for layer23. this client transforms the read and update requests from layer 3 (imsi read, location update) into several APDUs to be transferred via BTSAP interface. (interface to layer 1) here are two questions: how do i interface to this BTSAP? i see that there is another unix socket for that. do i need to expand main.c of layer23? i think that i cannot just start sending APDUs after starting layer23. there might be something like an initialization sequence before: - power on - reset - get atr - ... - send APDU - receive APDU - ... is there a defined sequence or flow chart for that? regards, andreas