METHOD FOR RESELECTING CELL BETWEEN RADIO ACCESS TECHNOLOGY SYSTEMS IN MULTI-RADIO ACCESS TECHNOLOGY SYSTEM MOBILE STATION

摘要

PURPOSE: A method for reselecting a cell between RAT(Radio Access Technology) systems in a multi-RAT system mobile station is provided to perform a cell reselection process between RAT systems in accordance with RR(Radio Resource)/GRR(GPRS Radio Resource) and URRC(UMTS Radio Resource Control) interfaces, thereby always selecting a better cell between the RAT systems. CONSTITUTION: If a UMTS cell satisfies a cell reselection standard, an RR/GRR(18) of a GSM/GPRS network layer temporarily stops the GSM/GPRS physical layer, informs an API(Application Protocol Interface)(40) of an RAT change start via an MM(Mobility Management)/GMM(GPRS-MM)(32), transmits UMTS cell information to a URRC(28), and requests to enter a UMTS cell(S11). The URRC(28) attempts a UMTS cell reselection, and informs the RR/GRR(18) whether to succeed in the cell reselection(S12). The RR/GRR(18) informs the API(40) of an RAT change failure in case of receiving a cell reselection failure from the URRC(28). The RP/GRR(18) initializes the GSM/GPRS physical layer in the case of receiving a cell reselection success, and then informs the API(40) that an RAT change is completed(S13).