Gaithersburg, Maryland, USA – October 01, 2025, GL Communications Inc., a global leader in telecom testing solutions, addressed the press regarding their ED-137 Telephone and Radio Emulators for testing Air Traffic communication systems. These solutions are trusted globally by Air Navigation Service Providers, and manufacturers of VCS, radios, recorders, and gateways. These fully compliant ED-137 emulators support Air-to-Ground and Ground-to-Ground communications, providing a simple and reliable way to test interfaces as Air Traffic Communication systems move to VoIP.

“GL offers advanced testing solutions for next-generation Air Traffic Communications networks, enabling precise emulation and load testing of Controller Working Positions (CWPs), Ground Radio Stations (GRSs), Analog-to-IP converters, and Gateways. Fully compliant with EUROCAE ED-137, these tools evaluate performance, functionality, and timing accuracy. They also support signaling and traffic emulation for Air-to-Ground and Ground-to-Ground interfaces. “said Vijay Kulkarni, CEO of GL Communications Inc.

MAPS™ Framework and ED-137 Solutions

GL’s Message Automation and Protocol Simulation (MAPS™) framework supports Analog, TDM, and VoIP technologies, emulating ED-137-compliant Radio, Telephone, and Recorder interfaces for ATM networks. Running on Windows®, MAPS™ uses a standard NIC and supports ED-137B and ED-137C (Change 1 & 2) with IPv6 compatibility. Validated with EUROCAE’s VOTER tool, these emulators guarantee compliance and reliability for testing CWP, VCS, GRS, Recorder, and Radio Gateway interfaces.

• MAPS™ ED-137 Radio Emulator – Emulates both GRS and CWPs for Air-to-Ground testing. Supports Push-to-Talk, SQUELCH, SELCAL, multicast/group communications, and scales up to 500 radios. Provides SIP call flow graphs, real-time logs, impairment testing, PTT Summation modes, DSCP marking, Dynamic Delay Measurement, and Python API automation
• MAPS™ ED-137 Telephone Emulator – Tests Ground-to-Ground communications with routine, priority, instantaneous, and position monitoring calls per ED-137/2B and 2C. Supports FAA Legacy Interworking, Override Call, Voice Call handling, and advanced scenarios like Call Transfer, Meet Me, Preset Conference, and Broadcast Conference. Handles hundreds of simultaneous calls, offers SIP visualization, and supports remote automation
• MAPS™ ED-137 Recorder – Emulates recording interfaces defined in ED-137 Volume 4. A single license can emulate hundreds of CWPs or radios and generate bulk Air-to-Ground and Ground-to-Ground recording sessions for load and performance testing

Advanced Testing Capabilities

The MAPS™ ED-137 framework enables custom protocol messages, negative testing, and IP impairments such as packet loss, duplication, out-of-sequence delivery, and latency. For ED-138 service quality monitoring, it provides MOS, PESQ, POLQA, jitter, packet loss, and delay statistics. All traffic can be monitored via GL’s PacketScan™ and analyzed locally or remotely with NetSurveyorWeb™.

Key Features

• Support for RTP audio, voice file playback, and DTMF signaling
• Up to 500 radios within a single software instance
• Call flow graphs with SIP headers and SDP details
• GRS simulation in Tx/Rx separated or combined modes
• Support for SQI, CLIMAX Delay, RMM/MAM, and Radio Remote Control
• IP address spoofing for endpoint simulation
• Portable setup for field testing and commissioning
• Remote automation with Python APIs

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