MAPS™ ED-137 Recorder Emulator

Simulate Call Recording at Controller, Radio and Recorder Interface

Overview

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.

MAPS™ ED-137 Recorder supports both ED-137/4B and ED-137/4C versions of Recorder Interface simulation. ED-137 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™ ED-137 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 & 4C versions, 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™ ED-137 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 signaling 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.

Main Features

Signaling and Traffic Simulation	Simulates recording interface at CWP, VCS, GRS and Recorder end points Supports all the features as per ED137C_Volume_4_Recorder Change 1 and Change 2 recommendations Supports both IPv4 and IPv6 Supports all three media transport methods: Embedded Binary Data, RTP over TCP and RTP over UDP 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 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 Customization of each CWP/GRS profile to emulate an AG/GG call Up to 500 RTSP sessions can be generated or recorded simultaneously Highly flexible architecture for custom testing scenarios Custom Properties and Operations can be included
ED137/4B Recorder	Scripts to automate PTT and Squelch operations on AG recording sessions Simulates Voting operation with two or more users (GRS) Simultaneous Call Transmission (SCT) with Squelch ON User can configure multiple users (radios) to simulate voting and simultaneous squelch operation Simulates call intrusion, call transfer and call hold operations on GG call Options to easily add custom call record data properties (like Caller, Callee, Frequency) and operations (like PTT, Squelch, Call Hold)
ED137/4C Recorder	All RTSP requests and response WG67-Version header updated to 'recorder.02' Supports recording 2-byte base R2S header and R2S header extensions (R2S-TLV) Recording client supports RTSP session keep alive Supports checking Recorder Server liveliness Simulation of proprietary CRD metadata Recorder Server supports RTSP session time out if no requests are received within timeout value Simulates Caller Rejected calls, Attended Call Transfer, Joining conference etc. Additional call properties include Call Type, Client Type, ClientId and Disconnect Reason New Operations includes ConfRef, Radio Access Mode, R2S and R2S-TLV
Traffic	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
Applications	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 Use Cases

MAPS™ ED-137 Recorder supports simulation of the following Use Cases–

CASE 1: Simulate AG call recording towards Recorder
Simulate AG call recording towards Recorder	MAPS™ ED-137 Recorder can be configured as CWP or GRS to simulate AG recording sessions towards the Recorder (device under test) to test its recording interface as per ED-137 volume 4.

CASE 2: Simulate GG call recording towards Recorder
Simulate GG call recording towards Recorder	MAPS™ ED-137 Recorder can be configured as CWPs to simulate GG recording sessions towards the Recorder (device under test) to test its recording interface as per ED-137 volume 4.

CASE 3: Testing Recorder interface of CWP/VC
Testing Recorder interface of CWP/VCS	In this test case, CWP or VCS vendors can use MAPS™ ED-137 Recorder (simulating Recorders) to test the Recorder interface of their equipment.

CASE 4: Testing Recorder interface of GRS
Testing Recorder interface of GRS	In this test case, MAPS™ ED-137 Recorder is simulating Recorder server to receive recording sessions from GRS thus testing Recorder interface of GRS.

Typical AG, GG and Recorder Interface Calls Recording

A typical ED-137 Recorder session between CWP-to-Recorder and GRS-to-Recorder simulation is as shown below.

MAPS™ ED-137 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/GG call recordings as per ED137-4B version

MAPS™ ED-137 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™ ED-137 Recorder (CWP) Call Generation

MAPS™ ED-137 Recorder (RECORDER) Call Reception

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

Simulate AG/GG call recordings as per ED137-4C version

MAPS™ ED-137 Recorder is enhanced to simulate AG /GG call recordings as per ED137-4C recorder interface version. MAPS™ supports performance and automated stress/load testing capabilities simulating hundreds of recording sessions over the Recorder interface.
The following events are supported at CWP/GRS during the call simulation -

RTSP Session Keep Alive - Recording Client assures RTSP session keep alive by sending RTSP GET_PARAMETER request periodically to Recording Server
Recorder Server Liveliness - checks whether the server is available or not to process and respond to the RTSP requests
Recording 2 Byte Base R2S Header and R2S Header Extensions (R2S-TLV) - R2S operation values are sent with RECORD and PAUSE messages for PTT/SQUELCH
Caller Rejected Calls – this event allows caller to reject the call before sending SETUP or TEARDOWN messages
Attended Call Transfer operations - This event is used to simulate Attended Call Transfer on GG call, where minimum 2 users need to be configured with proper Called Number (User 2 is considered as third-party number)
Joining Conference operations - This event is used to simulate the conference call while adder the user to the conference (Join Conference option) or removing user from the conference (Exit Conference option)

Simulate AG Call Recording

Simulate GG Call Recording

Resources

Item	Air Traffic Management
PKS118	MAPS™ ED-137 Radio (Includes PKS107, & PKS102)
PKS119	MAPS™ ED-137 Telephone (Includes PKS102)
PKS117	MAPS™ ED-137 Recorder (Includes PKS102)
PKS102	RTP Soft Core for RTP Traffic Generation
PKS107	RTP EUROCAE ED137

Brochures
Air Traffic Simulation using MAPS™ ED-137 - Recorder Brochure
Air Traffic Simulation using MAPS™ ED-137 - Radio Brochure
Air Traffic Simulation using MAPS™ ED-137 - Telephone Brochure
Air Traffic Management Test Solutions Brochure
MAPS™ SIP Brochure
GL Product Lists