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 helps validate protocol conformance and system performance in compliance with EUROCAE ED-137 standards.

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

GL’s integrated VQT tools assess voice quality by comparing received audio with the reference signal to calculate key metrics such as Mean Opinion Score (MOS), packet loss, jitter, delay, and out-of-sequence packets. The tools support ITU-standard algorithms like PESQ (Perceptual Evaluation of Speech Quality) and POLQA (Perceptual Objective Listening Quality Analysis) to provide 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 delivers a complete and trusted solution for ANSPs, OEMs, and system integrators involved in next-generation ATM deployments.