Description
A Sub-Network Manager (SNM) is a functional entity within the 3GPP Telecommunications Management Network (TMN) and later the Management System (MS) architecture. It operates at the Element Management Layer (EML) or potentially the Network Management Layer (NML), depending on the hierarchical model. The SNM has a defined management scope, which is a sub-network—a collection of Network Elements (NEs) grouped by geography, technology, vendor, or administrative domain. Examples include an SNM managing all Node Bs in a region, all eNBs from a specific vendor, or all core network elements for the Packet Switched domain.
The SNM performs the full FCAPS (Fault, Configuration, Accounting, Performance, Security) management functions for the NEs within its domain. It collects alarms and performance measurements from the NEs via southbound interfaces (e.g., using protocols like SNMP or CORBA). It can perform configuration updates, software downloads, and fault isolation and correction. The SNM often provides a vendor-specific or technology-specific management interface, abstracting the heterogeneity of the underlying NEs. It then presents a consolidated, aggregated view of its domain to northbound systems, such as a Domain Manager (DM) or Network Manager (NM), through standardized interfaces (e.g., the Itf-N interface).
Key components of an SNM include the management information base (MIB) containing the managed objects for its domain, mediation functions to translate between NE-specific protocols and information models, and a graphical user interface (GUI) for operators. Its role is crucial for scalable network management; instead of a single, monolithic manager handling thousands of disparate NEs, the network is partitioned into domains, each with a dedicated SNM. This allows for distributed processing, fault containment, and specialized management expertise for different network technologies.
Purpose & Motivation
The SNM concept was created to address the scalability and complexity challenges of managing large, multi-vendor, multi-technology telecommunications networks. Early network management approaches often involved proprietary element managers that could not communicate with higher-level, multi-domain systems, leading to operational silos. The problem was a lack of a standardized, hierarchical management architecture.
The 3GPP management architecture, defined in specifications like TS 32.102 (Telecom management: Principles and high level requirements) and TS 32.150 (Management and orchestration architecture), introduced the SNM to decompose the management problem. Its purpose is to provide localized, efficient management for a logical subset of the network. This solves the issue of overwhelming a central manager with data from all elements and allows for vendor-specific optimizations at the sub-network level. Historically, it evolved from the TMN's EML concept, providing a crucial layer of abstraction and mediation between heterogeneous network elements and unified, service-aware network management systems.
Key Features
- Manages a defined sub-network domain (e.g., vendor-specific RAN)
- Performs FCAPS functions for Network Elements within its scope
- Provides mediation between NE-specific interfaces and standardized northbound interfaces (e.g., Itf-N)
- Aggregates and correlates alarms and performance data from multiple NEs
- Enables scalable and distributed network management architecture
- Often provides a technology or vendor-specific management application
Evolution Across Releases
Introduced within the framework of the Evolved Packet System (EPS) management architecture. The initial concept positioned the SNM as a key component at the Element Management Layer, responsible for managing a set of eNBs or other network elements, with specifications defining its role and interfaces in documents like TS 32.102 and TS 32.150.
Defining Specifications
| Specification | Title |
|---|---|
| TS 32.102 | 3GPP TR 32.102 |
| TS 32.150 | 3GPP TR 32.150 |