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Universal Telephony Adapter (UTA)

Overview | Application Diagrams | Description
UTA specifications | UTA Connections | Buyer's Guide


The Universal Telephony Adapter (UTA) is a hardware adapter that interfaces a PC sound device to telephony equipment to provide a means of testing voice quality transmissions across the network. Used in conjunction with GL's VQuad™ software application, the UTA can be directed to automatically send and record sample voice files between nodes of a telephony network. These files can then be submitted to GL's Voice Quality Testing (VQT) software application for analysis according to widely accepted International Telecommunications Union (ITU) voice comparison algorithms.

The UTA is also capable of measuring Round Trip Delay (RTD) between nodes of the voice network. This is accomplished by utilizing an on-board pulse generator to transmit a fixed-frequency across the network. This pulsegen function is invoked through VQuad™ software commands to the UTA microcontroller. For more information on RTD measurement, please visit Network Delay Measurement webpage.

The UTA features all the circuitry necessary to universally adapt to any telephony instrumentation, including standard Plain Old Telephone Systems (POTS), digital hybrid interfaces, Voice over Internet Protocol (VoIP) networks, wireless cellular phones and mobile radios.

The UTA features an integral USB microcontroller that directs all software-controlled functions including: Audio IN Select (delay or audio measurement), RTD signal generation (pulsegen), and Push-To-Talk (PTT) control.

Application Diagrams

  1. Automated Wireless, Landline, and VoIP Path Analysis with VQT

    These configurations interface at the analog level (analog into the speaker and mic inputs of a mobile phone, analog inputs of a landline phone, and analog inputs of a VoIP phone). These systems can also perform roundtrip delay measurements.

  2. Network Delay Measurement

    The Universal Telephony Adapter (UTA) features a built in Round Trip Delay (RTD) measurement capability. Two UTAs can automatically determine the RTD, regardless of what network they may be analyzing. A one-way MANUAL delay measurement is also achievable using the UTAs and Adobe Audition. For more information on RTD measurement, please visit Network Delay Measurement webpage.


Theory of Operation
The UTA is an in-line adapter that allows a PC-based sound device to interface with all types of telephony equipment. This is accomplished by tapping into the audio signals coming from the telephony equipment and feeding them through the UTA circuitry and into the PC-based sound device. A simplified block diagram depicting the audio signal flow of the UTA is shown in the below image.

This configuration allows the PC to send sound waveforms from the audio device to the network interface and then across the network.

UTA specifications

Physical Dimensions:

Height: 1.52 in. (38.6mm)
Width: 4.17 in. (106.0mm)
Depth: 3.00 in. (76.2mm)
Weight: 0.613 lb. (0.178 kg)

Power requirements:

Input Voltage: +5VDC (derived from USB bus)
Current load: 175mA (typical)

External Connections:

USB 2.0: Type B USB Jack

Audio Input/Output Jacks:
Input/Output Impedance xxx ohms
Input/Output Level (V)

Landline In/Out Jacks:
Input/Output Impedance xxx ohms
Input/Output Level (V)

Mobile Phone Jack:
Input/Output Impedance xxx ohms
Input/Output Level (V)

Connector Specifications
Number of connections 4
power rating 16VDC@300mA
contact resistance 100mO MAX
insulation resistance 100mO or greater at 500VDC
voltage withstand 500V AC RMS, 1 minute
flammability UL94V-0 rated
life 5,000 cycles

UTA Connections

  1. Push-to-Talk LED
    When illuminated indicates that the PTT function is active. Te active state indicates that the radio has been placed in transmit mode. Conversely, the inactive state (LED off) indicates the radio is in receive mode. For pin-out information on wiring the radio to the UTA refer to the description of the PTT connector (Item #15).

  2. Trigger LED
    When illuminated indicates that an RTD pulse has been detected. This LED may also illuminate momentarily when connecting or disconnecting audio lines.

  3. Monitor Jack
    This 3.5 mm jack (stereo miniature phone type) provides for connection of a headset or amplified speakers to monitor the Audio In/Out signal.

  4. Power LED
    When illuminated indicates the UTA is receiving power and is ready to operate. The UTA is powered from the USB bus.

  5. Mobile Jack
    The "Audio In/Audio Out" port for connecting cellular phones or mobile radios to the UTA.

  6. Handset Jack
    For use with handset-type phones. Connect the curly cord of the handset to this jack.

  7. Talk/Line | Mobile/Landline Switch
    This switch has two functions depending on the type of telephony equipment connected to the UTA.

    If a handset-type phone is connected, the switch selects either Talk or Line mode. Line mode allows audio from the Edirol UA-20 sound device to pass through UTA. Talk mode is a feature that allows users to speak directly to each other through the handset microphone. When in Talk mode, the audio signal from the Edirol UA-20 is interrupted. The handset earphone is always enabled when the handset is connected to the UTA.

    If the telephony equipment (cellular, radio, or landline phones) is connected to either the mobile or landline jacks this switch must be in the UP position. This enables the audio path within the UTA for these types of phones. The down position disables the audio path from these types of phones.

  8. Landline Out Jack
    Audio Out port that connects to the Audio In of landline adapter-type phones that provide line level Audio In/Out ports.

  9. Landline In Jack
    Audio In port that connects to the Audio Out of landline adapter-type phones that provide line level Audio In/Out ports.

  10. Audio Out Jack
    Audio Out port that connects to the Audio In port of the Edirol UA-20 Audio Capture device.

  11. Audio In Jack
    Audio In port that connects to the Audio Out port of the Edirol UA-20 Audio Capture device.

  12. USB Jack
    Communications and power interface connection. Connect to the computer USB port directly or through a USB hub.

  13. Phone Jack
    For use with handset-type phones. Connect to the telephone base modular jack from which the handset curly cord was removed.

  14. 3-Wire/ 4-Wire Handset Microphone-type Switch
    For use with handset-type phones. For most phone handset types, the normal position is DOWN (4-wire). Switch to the UP (3-wire) position when using with 3-wire type handsets.

  15. PTT Terminal Block
    For use with radios that require activation of a push-to-talk function to transmit or receive audio signals. This terminal block is connected to the software-controlled relay internal to the UTA and provides a dry contact closure. When PTT is active (PTT LED on), pins 2 & 3 are shorted. When PTT is inactive (PTT LED off), pins 1 & 2 are shorted.

        Pin 1 - Normally Closed
        Pin 2 - Common
        Pin 3 - Normally Open

Buyer's Guide:

Item No. VQuad™ Network Options
VQT010 VQuad™ Software (Stand Alone)
VQT013 VQuad™ with SIP (VoIP) Call Control
VQT015 VQuad™ with T1 E1 Call Control
Item No. VQuad™ Miscellaneous
VQT202 VQuad™ GPS Location and Timing Option (per node - including GPS receiver)
VQT030 Network Command Center (Multi-Node Command and Control Center for VQuad™ Systems)
VQT240 Universal Telephony Adapter (UTA) with Round Trip Delay Measurement
Item No. VQT
VQT002 Voice Quality Testing (PESQ only)
VQT006 VQT w/ POLQA Server License
VBA032 Near Real-time Voice-band Analyzer

* Specifications are subject to change without notice.

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