HANDOFF METHOD FOR SUPPORTING REVERSE SYNCHRONOUS TRANSFER MODE IN MOBILE COMMUNICATION SYSTEM

摘要

PURPOSE: A handoff method for supporting a reverse synchronous transfer mode in a mobile communication system is provided to enable supporting of a soft handoff and a hard handoff, and reduce a delay time caused due to a timing tracking process performed when an existing Non-USTS mode introduction plan is adopted as it is by completely excluding the timing tracking process. CONSTITUTION: A terminal periodically receives a measurement control message for a pilot reception signal(S401), measures a size of the pilot signal(S402) and reports the measurement result value to a control station(S403). The control station determines to perform a handoff as the terminal advances to an overlapped area(S404). The control station requests a physical layer of a target base station to set up an SC1 and CC1(S405). The target base station starts transmission and reception through a radio link(S406) and reports a set-up completion to the control station(S407). The control station provides an active set update message to a terminal(S408). The terminal starts receiving about the target base station and obtains synchronization(S409), and then completes an active set addition for the target base station(S410). The control station determines release of the radio link when it determines that the terminal has advanced into a cell(B) region(S411). The control station requests a source base station to release the radio link(S412). The source base station suspends transmission/reception for the terminal(S413) and reports the radio link release completion to the control station(S414). The control station provides an active set update message to the terminal(S415). The terminal discontinues receiving for the source base station(S416) and removes the source base station from an active set(S417). The control station determines change into a USTS(Uplink Synchronous Transmission Scheme) mode(S418). The control station a scrambling code(SC2) and a channel code(CC2)(S419). The control station calculates an adjustment value of a signal transmission start time(S420).