As an extremely large number of network equipment are installed by telecom carriers to build a mobile communications network, there is a significant number of NEs that affect communication services because of faults. It is important to monitor network equipments 24 hours a day to ensure the stable provision of high-quality services. Operation And Maintenance (OAM) by the Operation System (OpS) is therefore essential in communication networks nowadays. Hitherto, mobile carriers had to resort to labor-intensive means to maintain the service quality whenever the network was expanded | W-CDMA Mobile Communications System. Edited by Keiji Tachikawa Copyright 2002 John Wiley Sons Ltd. ISBN 0-470-84761-1 5 Operation System Masafumi Onuki Nobutaka Nakamura Haruo Mizumoto Takeshi Yamashita Kazuhiko Hara and Kazuaki Terunuma Overview As an extremely large number of network equipment are installed by telecom carriers to build a mobile communications network there is a significant number of NEs that affect communication services because of faults. It is important to monitor network equipments 24 hours a day to ensure the stable provision of high-quality services. Operation And Maintenance OAM by the Operation System OpS is therefore essential in communication networks nowadays. Hitherto mobile carriers had to resort to labor-intensive means to maintain the service quality whenever the network was expanded. In the future it will be necessary to build an operation framework that can take swift action based on strategic information management and assure maximum quality with minimal personnel. This chapter reviews the functions and the mechanism of OpS which is expected to become increasingly important with the introduction of International Mobile Telecommunications-2000 IMT-2000 with reference to actual system construction. Positioning of OpS The layers depicted in Figure show the OAM functions based on the Telecommunication Management Network TMN model generally specified by the ITU-Telecommunication Standardization Sector ITU-T 1 . The bottom layer represents Network Element NE whereas the element management layer positioned above that executes NE management on an individual basis. The NW management layer above the element management layer realizes functions to manage the entire network which consists of multiple NEs. The service management layer above the NW management layer is positioned to support functions for managing services provided over the network. On the basis of such a TMN model the 3rd Generation Partnership Project 3GPP which .
