FIELD: technology for performing transfer of service between systems.
SUBSTANCE: in accordance to method, transfer of service of mobile station 100 from system UTRAN to system GSM is launched by sending message "command for transferring service from UTRAN" from UTRAN system. If "command for transferring service" is sent transparently together with "command for transferring service from UTRAN", while "command for transferring service" has informational element, set for denoting, that encoding should be started, in accordance to method, encoding is started immediately after transferring service to GSM system, so that first frame of data, transmitted by mobile station in GSM system, is an encoded frame of data. If prior connection exists of encoded data belonging to UTRAN system then, when message "command for transferring service from UTRAN" is received, after transfer of service to GSM system, in accordance to method, usage of data encoding with data connection is continued without interruption.
EFFECT: increased efficiency.
4 cl, 7 dwg
