The present document describes the requirements for the management of performance measurements and the collection of performance measurement data across a Public Land Mobile Network (PLMN). It defines the administration of measurement schedules@ the generation of measurement results in the Network Elements (NEs) and the lran sfer of these results lO the Operalions System (OS). It also descri bes how the various requiremcnls can be modelled as part of the generic PLMN information model. A set of measurements avai lable for collection by NEs arc described in annex B@ effort has been made to ensure consistency in the definition of measurements between different NEs. The following is beyond the scope the present document: - how the data@ once accumulated and collected. could or should be processed@ stored@ or presented LO an end user; - the information which may be obtained through the collection and processing of call or event related records which have been produced by the NEs primarily for the pUfJX)Se of raising bills and other charges. The management requirements have been derived from existing telecommunications operations experience. The management defini tions were then derived from other standardisation work so as to minimise the re-in vention factor. References are given as appropriate. The objective of the present document is: to normalise the description of each measurement; and to produce a common description of the management technique for result accumulation and transmission across a management interface. The normalisation is intended lO rcsult in comparability of measurement data produced in a multi-vendor PLMN. As far as possible. ex isling standardisation in the area of performance management has been re-used and enhanced where particular requirement s@ peculiar to the mobile telephony environment@ have been recognised. Field of application The present document considers all aspects of performance management for a PLMN and its NEs defined in the GSM core Technical Specifications. However@ only those aspects@ which are GSM specific and particular to PLMN operation arc included in the present document. Olher performance measurement aspects of descri bed NEs and performance measurement aspects of NEs not described by the GSM core Technical Specifications arc included for information pUfJX)Se-.. in annex E or may be found in referenced documents.