Air traffic control centers are required to provide continuous "ground/ground" and "ground/air" voice communication recordings with synchronized flight related data, for establishing “air traffic incident” chronology, replay, improving safety, audits, statistics, and training purposes.
ED137/4B defines inter-operability standards for the next generation VoIP Air Traffic Recorder. These next generation recorders are specially designed for all traffic control towers and centers to simplify the recording, archiving, and playback of voice communications.
GL’s MAPS™ ED137 Recorder (PKS117) can simulate Recorder interface for both Air-to-Ground (AG) and Ground-to-Ground (GG) calls at Controller Working Position (CWP), Ground Radio Station (GRS) and Recorder endpoints as per ED-137/4B, as defined under EUROCAE (European Organization for Civil Aviation Equipment) Working Group 67.
MAPS™ ED137 Recorder can simulate AG/GG call recording towards Recorder and testing Recorder interface of CWP/VCS and GRS.
MAPS™ ED137 Recorder supports Real Time Streaming Protocol (RTSP) to establish, terminate and maintain media sessions to deliver media to recording servers. Active recording requires an established session (i.e. a certain number of parameters that are exchanged between entities prior to any recording). CWP/VCS, Radio and Recorder use RTSP for such sessions. As RTSP relies on a transport layer protocol (TCP or UDP), these entities use SIP to exchange capabilities and connection information (i.e. IP address, port number, and transport protocol).
The MAPS™ profile editor feature allows users to easily configure multiple CWPs, GRS and Recorder profiles, allowing to simulate multiple CWP, GRS and Recorder entities. The product also supports transmission and detection of various RTP audio traffic such as real-time audio, voice file, digits, single tone and dual tones. The software not only provides complete control over call scenarios to be tested, but also the ability to customize the network parameters for signaling and VoIP traffic. It has the capability of generating more than hundreds of recording sessions to verify performance and load testing.
GL tools for signalling emulation and voice quality testing offer an end-to-end test solution for testing connections from the radio interfaces to the Controller Working Position (CWP) and recording voice communications over the network. GL’s Air Traffic Management Solution also includes MAPS™ ED-137 Telephone Emulators and MAPS™ ED-137 Radio Emulators.
Signalling and Traffic Simulation
- Simulates recording interface at CWP, VCS, GRS and Recorder end points
- Supports all three media transport methods: Embeded Binary Data, RTP over TCP and RTP over UDP
- Emulates ED-137/4B Recorder interface at CWP, GRS and Recorder endpoints
- Simulates Recorder interface on multiple CWPs and Radios from single instance of MAPS™
- Simulates Recorder interface for both Air-to-Ground and Ground-to-Ground calls
- Supports RTP over independent UDP, independent TCP and Interleaved RTSP
- Supports simulating multiple recording servers from single instance of MAPS™
- Recorder node records the voice on sessions to audio files and saves Call Record Data to CSV files
- Scripts to automate PTT and Squelch operations on AG recording sessions
- Customization of each CWP/GRS profile to emulate an AG/GG call
- Options to easily add custom call record data properties (like Caller, Callee, Frequency) and operations (like PTT, Squelch, Call Hold)
- Up to 200 RTSP sessions can be generated or recorded simultaneously
- Highly flexible architecture for custom testing scenarios
- Supports various traffic actions on the call such as Talk using Microphone, Playback to Speaker and Send & Record audio file.
- Supports user-defined and automated traffic actions on the call
- Supports all standard codecs, including G.711 (Mu-Law and A-Law) and G.729
- On field testing and troubleshooting by technicians
- In-the-field installation, system configuration and commissioning
- Functionality testing of nodes in next generation VoIP ATM
- Centralized recording of Air Traffic
- Real-time and/or historical data analysis
Simulation of AG, GG and Recorder Interface Calls Recording
A typical ED137 Recorder session between CWP-to-Recorder and GRS-to-Recorder simulation is as shown below.
MAPS™ ED137 Recorder simulates complete call flow and provides message decodes for each session. The PTT, and Squelch (Record) events are also updated to the call graph indicating the time at which the event occurred.
|Typical AG Call Recording Scenario ||Typical GG Call Recording Scenario|
Simulation of AG call recording between CWP and Recorder
MAPS™ ED137 Recorder can be configured as CWP and RECORDER to simulate AG calls recordings. MAPS™ supports performance and automated stress/load testing capabilities simulating hundreds of recording sessions over the Recorder interface. All the recorded files are automatically saved at Recorder terminal in GL's proprietary file format (*.glw).
The following events are supported at CWP/GRS during the call simulation -
- Voting – this event can be applied on a session to send RTSP messages indicating Rx stream selected by the voting algorithm.
- Simultaneous SQU – if applied on a session, simulates recording simultaneous SQU received at VCS on different frequencies
- Start Squelch – this event can be applied to indicate squelch detection (at VCS) to recorder.
- Call Intrusion – if this event is applied on a session then RTSP messages are sent to simulate call intrusion scenario on GG call.
- Call Transfer – if this event is applied on a session then RTSP messages are sent to simulate call transfer scenario on GG call.
|MAPS™ ED137 Recorder (CWP)
|MAPS™ ED137 Recorder (RECORDER)
The Call Record Data for AG and GG calls are saved in CSV file format. Call Record Data entry for each recorded call in the CSV file will also contain the recorded audio file. These audio files are in GL’s proprietary format (GLW). All audio files in GLW file format can be automatically converted to PCM/WAV files using GL's Audio File Conversion Utility, and playback these audio files using utilities such as Goldwave or Adobe Audition.
Call Record Data CSV File