Automatically Detected and Manually Cleared

Description

Automatically Detected and Manually Cleared (ADMC) is a fundamental classification within the 3GPP Fault Management (FM) framework defined across multiple Technical Specifications (TS). It categorizes network faults or alarms based on their detection and clearance mechanisms. An ADMC alarm is one where the fault condition is automatically identified by the network's monitoring systems—typically through performance threshold violations, protocol error detection, or hardware failure indicators—but the resolution of that fault requires manual intervention by operations and maintenance personnel.

The architecture supporting ADMC classification is embedded within the Operations, Administration, and Maintenance (OAM) systems of both the Radio Access Network (RAN) and Core Network (CN). Key components include the Network Element (NE) managers, which generate raw alarm notifications, and the Element Management System (EMS) or Network Management System (NMS), which processes, categorizes, and presents these alarms according to standardized severity and clearance type classifications like ADMC. The process begins with continuous monitoring of Key Performance Indicators (KPIs), hardware status, and software processes. When a predefined fault condition is met (e.g., a link failure, a board malfunction, or a severe performance degradation), the NE triggers an alarm notification. This notification includes attributes such as alarm identifier, perceived severity (Critical, Major, Minor, Warning), probable cause, and the proposed clearance type—in this case, ADMC.

Once an alarm is classified as ADMC, it enters a specific workflow within the Network Operations Center (NOC). The alarm is logged in the Fault Management system with a status indicating it requires manual attention. It appears on operator consoles, often filtered and prioritized alongside other ADMC and automatically cleared alarms. The manual clearance process involves a technician or engineer diagnosing the root cause, which may require physical inspection, hardware replacement, complex reconfiguration, or software patching—actions that cannot be safely or reliably automated. After the corrective action is performed, the operator must manually acknowledge and clear the alarm in the management system, updating its status and often providing closure comments.

The role of ADMC in the network is crucial for maintaining service quality and efficient operations. It provides a clear demarcation between faults that can be handled autonomously by self-healing mechanisms (like Automatic Detected and Automatic Cleared - ADAC alarms) and those requiring human expertise. This classification helps in resource allocation, process automation, and operational efficiency. By standardizing this category across 3GPP specifications like TS 28.111 and TS 32.111, it ensures multi-vendor interoperability and consistent alarm handling procedures for network operators managing complex, heterogeneous networks.

Purpose & Motivation

The ADMC classification was created to bring structure and standardization to the chaotic world of network fault management. Prior to its formalization in 3GPP Release 8, alarm handling was largely vendor-specific, with inconsistent definitions for detection and clearance methods. This made multi-vendor network management inefficient, error-prone, and resource-intensive. Operators struggled to automate processes or train staff effectively when each network element used different terminology and workflows for similar faults.

The primary problem ADMC solves is the clear categorization of faults that, while detectable by automated monitoring systems, inherently require human judgment, physical action, or complex decision-making to resolve. Not all faults can or should be fixed automatically; some interventions carry risks of service disruption or require specialized knowledge. By defining ADMC as a standard clearance type, 3GPP enabled the development of standardized OAM interfaces, alarm reporting formats, and operational procedures. This allows Network Management Systems (NMS) to intelligently route alarms, assign tickets to the correct support teams, and generate accurate reports on Mean Time To Repair (MTTR) for manually cleared faults.

Historically, the motivation stemmed from the telecom industry's push toward the Telecom Management Network (TMN) framework and enhanced operational efficiency. As networks grew more complex with 3G and 4G deployments, the volume of alarms increased exponentially. Distinguishing between automatically and manually cleared alarms became essential for prioritizing operator workload and investing in automation where it provided the most return. ADMC, alongside other categories like ADAC (Automatically Detected and Automatically Cleared), formed the backbone of a rationalized, efficient fault management process that is critical for achieving high network availability and reducing operational expenditures.

Key Features

• Standardized alarm clearance classification within 3GPP FM framework
• Requires manual intervention by O&M personnel for fault resolution
• Integral part of alarm reporting in Itf-N and other OAM interfaces
• Enables consistent fault workflow management across multi-vendor networks
• Supports operator workload prioritization and resource allocation
• Facilitates accurate reporting on manual repair times and operational efficiency

Evolution Across Releases

Defining Specifications