ngle variable model. SNMP is viable in dealing with single network elements whereas CMIP is preferred at higher management levels where a single agent represents the information associated with several NEs. 8.3.2 Standard Development Organizations and Forums A number of standard development organizations (SDOs) have been working to specify OSS specifica- tions and models for fixed and wireless systems. The most prominent one is TeleManagement Forum (TMF) which was formed in 1988. Beside TMF, network management practices of 3GPP, IEEE, and ITU-T are also discussed in this section: 3GPP: 3GPP TSG7 SA WG5 specifies the management framework and requirements for management of 3G systems. It focuses on delivering the architectural descriptions of the telecommunication management network (TMN) and coordinating across TSGs all work pertinent to the 3G system telecom management. ATIS: ATIS (Alliance for Telecommunications Industry Solutions) key committee for OSS is TMOC. TMOC (Telecom Management and Operations Committee) develops OAM&P standards, and other documentation related to OSS with an emphasis on standards devel- opment related to USA communication networks. ETSI: The TISPAN working group 8 is responsible for telecom management standards across all fields under the umbrella of ETSI organizations. Besides, TISPAN WG8 other ETSI technical committees produce technology specific Management Information Bases (MIBs). IEEE: OSS activities take place in an IEEE 802 LAN/MAN working group. This WG develops Local Area Network standards and Metropolitan Area Network standards. The IEEE 802.16-2009 standard incorporates the IEEE 802.16-2004, IEEE 802.16e-2005, IEEE 802.16-2004/Cor1-2005, IEEE 802.16f and IEEE 802.16g standards into a single document (WiMAX and MBWA systems are expected to utilize network management guidelines 7 3GPP TSG (Technical Specification Group) SA (Services and Systems Aspects) WG5 (Telecom management). Core Networks and Operations Support Systems which are based on ITU-T and TM Forum specifications). 