FIELD: telecommunication networks. SUBSTANCE: proposed system and method may be used for user's data transmission inside shared ground mobile communication network from A-BIS interface to A-interface. Synchronization frame is first shaped and then transmitted according to specifications of Global system for mobile communications (GSM) 08.60 As soon as initial synchronizing procedure is completed, modified GSM 08.60 frame is used between speed recorder/adapter unit and particular base transceiver station servicing mobile station to transmit greater amount of useful user's data load through established communication line. Modified GSM 08.60 data frame serves to raise useful data load from usual 13.5 Kbit/s to more desirable 14.4 Kbit/s without changing specified transmission speed of Kbit/s supported by internetting function and by base transceiver station. EFFECT: ability of adapting user's data protocol and transmitting it from one to other associated telecommunication network. 26 cl, 6 dwg
