G.165: Line Echo Canceller (LEC) Software

G.165: Line Echo Canceller (LEC) Software

GAO’s G.165, Line Echo Canceller (LEC) Software, cancels electrical line echoes caused by 2-to-4 wire conversion hybrids in telephone lines. The line echo canceller is also designed for integration with other software modules from GAO such as our DTMF Encoder/Decoder to enhance performance.

Line echo cancellation can be used in long distance voice communication, especially in links involving satellite networks and intercontinental long-haul circuits. It can also be employed in addition to echo suppressors for long delays. GAO’s line echo canceller consists of two user-callable functions that perform echo cancellation and initialization operations.

Features of Line Echo Canceller (LEC) Software - G.165

  • Implemented in assembly or C.
  • User-callable functions.
  • Double-talk detection.
  • Ideal for full-duplex operation.
  • Compliant with the ITU-T G.165 recommendation.

G.168: Digital Network Echo Canceller

GAO’s Digital Network Echo Canceller (ITU-T G.168) software module is intended for use in the 4-wire portion of a circuit and is used for reducing the echo by digitally subtracting an estimated echo from the circuit echo. GAO’s G.168 echo cancellation software has the following fundamental requirements:

  • Rapid convergence;
  • Low returned echo level during single talk;
  • Low divergence during double talk;
  • Assured double talk detection;
  • Proper operation during facsimile and low speed (9.6 kbit/s) voice-band data transmissions.

Features of Digital Network Echo Canceller (ITU-T G.168)

  • Implemented in assembly or C.
  • User-callable functions.
  • Double-talk detection.
  • Configurable echo tail length options: 8, 16, 32, 64 or 128 msec.
  • Compliant with the ITU-T G.168 recommendation.

For ITU-T standard on G.165, click ITU-T, G.165 Standard.

For a complete list of GAO’s Telephony Software products, please see GAO’s Telephony Software.

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