OTA format

[sats]

man! intresting format incoming OTA binary message(as WAP settings and sim toolkitts command)- i have some dump of it-it not chiphered format(for sim toolkit action(change IMSI)), but friends who work in mobile provider-say then ota message chiphering some key and use this algo:1)  in message determine what TAP application was work with OTA
2)detemine what key use for chiphering (or dechiphering)
3) determine use the counter or not(what counter i don't know)
4) determine some algorithm of action
hwo can help in this questions or may consult please ask!!!