GL Communications targets air traffic VoIP with ED-137 test suite
GL Communications has drawn attention to its suite of voice-over-IP test and monitoring tools aimed at Air Traffic Management networks, as aviation operators continue migrating voice infrastructure from legacy TDM circuits to IP-based systems. The Gaithersburg, Maryland firm says its products cover the full lifecycle of ATM voice validation, from pre-deployment emulation through to live-site troubleshooting.
The release centres on three product families. The MAPS platform handles ED-137 interface emulation across Radio, Telephone and Recorder endpoints. PacketScan and NetSurveyorWeb cover ED-138 network monitoring. The Timing Measurements in Air Traffic Management solution, known as TM-ATM, addresses end-to-end voice-path delay and quality assessment across analogue, TDM and IP links.
What the products do
MAPS emulates the Controller Working Position and Ground Radio Station entities that sit at the heart of air-to-ground communication, supporting push-to-talk handling, multicast RTP, SELCAL and priority call routing. For ground-to-ground traffic, it handles instantaneous, direct and indirect calls, conferencing, hold and transfer. GL says all three emulators are validated against the EUROCAE VOTER interoperability test tool and support the ED-137B and ED-137C specification revisions, including their Change 1 and Change 2 updates. FAA Addendums 2, 4 and 5 are also covered, giving the toolset applicability in both European and US airspace environments.
PacketScan captures and decodes SIP, SDP and RTP traffic at the protocol level, reporting per-call MOS and R-Factor scores, packet loss, jitter and delay for live or recorded traffic. NetSurveyorWeb aggregates data from multiple PacketScan probes into a centralised web dashboard with real-time alarms, historical reports and event correlation for distributed ATM installations.
TM-ATM extends the picture to timing-critical measurements. It uses GPS-based timestamping to correlate PTT activation, squelch events, main-to-standby switching, and end-to-end voice-path delay across interfaces, with PESQ and POLQA support for perceptual voice quality scoring. The system ships in rack-mounted and portable configurations for lab, commissioning and field use.
Vikram Kulkarni, Sales Director at GL Communications, said the solutions "support validation and troubleshooting of Air-to-Ground and Ground-to-Ground communications across Analog, TDM and IP networks" by combining protocol simulation, network monitoring and event-based timing measurement in a single ecosystem.
Market context and regulatory backdrop
The migration of ATM voice from TDM to IP is a slow-moving but high-stakes transition. EUROCAE's ED-137 family of standards governs VoIP interoperability for air traffic control in European airspace, while ICAO and national regulators including the FAA impose their own addenda. The pace of adoption has accelerated as legacy ISDN and analogue circuits reach end-of-life, but safety regulators demand rigorous pre-deployment validation before any new voice path goes live.
GL operates in a specialist niche alongside a small number of vendors offering ED-137 conformance tooling and network probes. Buyers are typically air navigation service providers, avionics integrators and defence communications contractors, all of whom face stringent certification requirements before equipment can enter operational service. The dual requirements of protocol conformance and measurable voice-path timing make the category technically demanding and relatively insulated from the commoditisation pressures that affect mainstream enterprise VoIP testing.
The company's stated support for full IPv6 operation is a practical requirement given European regulatory timelines encouraging IPv6 adoption across public-sector networks. As ATM voice networks grow in complexity, the ability to aggregate multi-probe monitoring data through a centralised dashboard is increasingly relevant to large air navigation service providers managing distributed ground radio infrastructure across multiple sites.