Description
Bad Quality Call (BQC) is a standardized performance measurement defined in 3GPP specifications that quantifies the proportion of voice calls that experience unacceptable quality levels leading to premature termination. The metric operates by monitoring specific call quality parameters throughout the call duration and comparing them against predefined thresholds. When these thresholds are breached, the system classifies the call as a BQC event, which contributes to the overall BQC rate calculation.
The technical implementation of BQC involves continuous monitoring of multiple quality indicators during active calls. These indicators include but are not limited to: speech quality metrics (like Mean Opinion Score equivalents), frame error rates, packet loss rates, delay variations, and signal strength measurements. The network elements responsible for call processing, particularly in the Radio Access Network and Core Network, collect these measurements in real-time. The system employs sophisticated algorithms to correlate multiple degradation factors and determine whether the overall call quality has fallen below acceptable levels.
BQC calculation follows specific formulas defined in 3GPP specifications, typically expressed as a percentage of total calls. The measurement period, sampling methodology, and threshold values are standardized to ensure consistency across different network implementations and operators. The metric is calculated both on a per-cell basis and network-wide, allowing operators to identify both localized issues and systemic problems. The data collection infrastructure includes probes, performance management systems, and specialized measurement functions integrated into network elements.
The role of BQC in network management extends beyond simple measurement to active quality assurance. Network operators use BQC data to trigger automated optimization processes, identify problematic network areas, and prioritize maintenance activities. The metric integrates with Self-Organizing Network (SON) functions to enable automatic parameter adjustments that improve call quality. BQC measurements also feed into customer experience management systems, providing insights into actual user-perceived quality rather than just technical network performance.
Purpose & Motivation
BQC was created to address the fundamental challenge of objectively measuring and improving voice call quality in mobile networks. Before standardized quality metrics, operators relied on subjective customer complaints and basic technical measurements that didn't accurately reflect user experience. This made it difficult to proactively identify and resolve quality issues before they significantly impacted customer satisfaction. The introduction of BQC provided a standardized, objective method for quantifying call quality degradation.
The historical context for BQC development emerged during the transition to 3G networks, where voice quality became more variable due to packet-switched transmission and increased network complexity. Traditional metrics like dropped call rates didn't capture quality degradation that didn't result in complete call failure. BQC filled this gap by measuring calls that remained connected but provided poor user experience. This was particularly important as voice services remained the primary revenue source for operators, making quality maintenance critical for business success.
BQC solves the problem of invisible quality degradation by providing early warning indicators before calls completely fail. It enables operators to implement proactive quality management strategies rather than reactive problem-solving. The metric also facilitates benchmarking across different network technologies and operators, driving industry-wide quality improvements. By focusing on user-perceived quality rather than just technical parameters, BQC aligns network optimization efforts with actual customer experience.
Key Features
- Standardized quality threshold definitions for consistent measurement across networks
- Real-time monitoring of multiple quality parameters during active calls
- Integration with network management systems for automated quality optimization
- Support for both circuit-switched and packet-switched voice services
- Correlation capabilities linking quality degradation to specific network elements
- Historical trending and reporting for long-term quality management
Evolution Across Releases
Initial introduction of BQC as a standardized performance metric in 3GPP specifications. Defined basic measurement methodology, threshold values, and calculation formulas for UMTS networks. Established the foundation for objective call quality assessment across different network implementations.
Defining Specifications
| Specification | Title |
|---|---|
| TS 45.913 | 3GPP TR 45.913 |