地區維護站 設施及設備維護站 國際傳輸網路維運系統 監視控制系統 中介設備 光終端機 調度及管理系統 非同步數位階層 性能監視 同步數位階層 傳輸次網路維運控制系統 Area maintenance station AMS Facility and equipment maintenance station FEMS International transmission subnetwork controller system ITSNC Monitor and control MAC Mediation device MD Optical line terminating equipment OLTE Provisioning and management system PAMS Plesiochronous digital hierarchy PDH Performance monitoring PM Synchronous digital hierarchy SDH Transmission subNetwork controller system TSNC