IP/VoIP Protocol Simulators

Core Network Simulators

Voice Quality Testing for Air Traffic Management

Validates IP-based Air Traffic Management (ATM) systems by emulating ED-137-compliant components like Controller Working Positions and Ground Radio Stations. Delivers precise voice quality assessment using ITU-standard metrics such as MOS, PESQ, and POLQA for every Push-To-Talk and Squelch event.

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ED-137 and Voice Quality Testing (VQT) solutions

Overview

GL’s ED-137 and Voice Quality Testing (VQT) solutions ensure clear, reliable voice communication across modern IP-based Air Traffic Management (ATM) systems. These tools emulate critical elements of the air traffic voice network, including Controller Working Positions (CWP), Ground Radio Stations (GRS), and the intervening IP infrastructure. By simulating and monitoring both Ground-to-Ground and Air-to-Ground calls, GL’s solution validates protocol conformance and system performance in compliance with EUROCAE ED-137 standards.

Through advanced protocol emulation, the system replicates realistic operational scenarios such as call setup, registration, and signaling exchanges, particularly Push-To-Talk (PTT) and Squelch actions vital for pilot-controller communication. Each PTT or Squelch event is treated as an independent session, providing fresh voice quality measurements for every transmission. This is crucial because, in Air-to-Ground communications, the signaling call remains established while only PTT/Squelch actions vary during operation.

GL’s integrated VQT tools assess voice quality by comparing received audio with reference signals to calculate metrics such as Mean Opinion Score (MOS), jitter, speech level gain, and Noise level gain. The tools support ITU-standard algorithms like PESQ (Perceptual Evaluation of Speech Quality) and POLQA (Perceptual Objective Listening Quality Analysis) to deliver accurate and reliable quality scores.

Real-time monitoring is supported over IPv4/IPv6 networks, with results visualized using protocol ladder diagrams and summary views. By combining ED-137 protocol emulation with high-precision voice quality testing, GL provides a complete solution for Air Navigation Service Providers (ANSPs), Original Equipment Manufacturers (OEMs), and system integrators involved in next-generation ATM deployments.



Key Features

  • Standards compliance – Supports ED-137 (Air-to-Ground, Ground-to-Ground) standards defined by EUROCAE
  • Full network emulation – Simulates CWP, GRS, and IP infrastructure for realistic call scenarios
  • Session-based testing – Treats each PTT and Squelch action as an independent session
  • Voice quality measurement – Calculates MOS, jitter, delay, packet loss, and out-of-sequence packets
  • ITU-standard algorithms – Supports PESQ (ITU-T P.862) and POLQA (ITU-T P.863) for objective voice quality assessment
  • Real-time monitoring – Works over IPv4/IPv6 networks with live statistics
  • Detailed analysis – Protocol ladder diagrams and summary views for easy visualization
  • Integrated VQT and ED-137 – Combines protocol emulation with high-precision voice quality testing


Benefits

  • Ensures communication clarity – Validates pilot-controller voice quality and signaling reliability
  • Improves operational safety – Monitors critical PTT/Squelch events in real-time
  • Supports compliance testing – Confirms conformance with ED-137 standards
  • Enhances troubleshooting – Provides detailed session-level metrics and call traces
  • Accelerates deployment – Reduces risk in next-generation IP-based ATM network rollouts

Use Cases

  • Air-to-Ground call verification – Monitor PTT/Squelch, signaling, and voice quality
  • Ground-to-Ground system testing – Validate call flows and priority calls between ATC centers
  • Voice quality assessment – Use PESQ/POLQA to evaluate voice quality (MOS)
  • End-to-end ATM network testing – Combine protocol emulation with VQT for complete operational validation