Method and system for synchronizing user data

A system for synchronizing user data, comprising an old mobility management unit and a new mobility management unit, wherein

• the old mobility management unit is configured, when a UE moves into a coverage area of the new mobility management unit, to send an indication of whether a bearer modification procedure is to be triggered to the new mobility management unit;
• and
• the new mobility management unit is configured to determine whether to trigger the bearer modification procedure according to the indication;
• wherein the old mobility management unit is further configured, when the user subscription data of the UE at the old mobility management unit and in an idle state are changed and a related activated bearer modification is to be triggered, to store only the updated user subscription data and to record an identification to indicate that the bearer modification procedure is triggered when the UE enters a connected state.