Telinnovation Echo Canceller available for DSP Devices and High-Density Voice Processor- Texas Instruments

Texas Instruments deployed its Telinnovation echo canceller which compliant with G.168-2004 standard. Telinnovation echo canceller software is a robust echo cancellation solution, providing industry-leading channel densities. The echo canceller is available as a function for the TMS320C64x- and TMS320C64x+  DSP devices and will also be available as an image for the TNETV3020 High-Density voice processor. The Telinnovation echo canceller can converge and suppress echoes within 25ms 90% of the time.

Key Benefits of Telinnovation echo canceller includes:

• DSP Based solution (versus ASIC) – Allows ANY critical functionality to be solved with software, fast and efficiently
• Field Proven Solution – Over 20 million ports in service.
• Breadth of Deployment – Fixed and Mobile Carriers and Enterprises
• Long Tail Cancellation (up to 192ms)
• Fast Convergence
• Double talk detection
• Support of wireless infrastructure
• Ability to handle various signaling protocols

Key Features of Telinnovation echo canceller includes:

• DSP-based solution (versus ASIC) allows any critical functionality issues to be solved with software, fast and efficiently
• Breadth of deployment: class 4/5, enterprise, and wireless
• Field-proven echo canceller: 15,000,000 ports in service with over one billion calls per day
• Long tail cancellation
• Fast convergence

The standard feature set for either the Telinnovation Image and function includes:

• G.168 – 2004 Echo Cancellation on all supported channels
• G.169 Automatic Level Control (ALC) – Programmable from -23 to -15 dBm0
• Echo Tail – settings up to 192ms planned
• High Level Compensation (HLC)- allows for receive level attenuation where needed
• Comfort Noise Generation
  • – Tone Detection (Modem disable tones)
  • – Programmable Idle Code
  • – Tone Detection
  • – Mid Call Trigger (MCT) - Detects DTMF “#” for feature activation
  • – C7 Bypass
  • – C7 Generate/ Detect/Measure
  • – C5 Bypass
  • – C5 Generate/Detect (Legacy) Wireless Infrastructure Support (Voice Quality Enhancements – VQE)

Echo Detection and Cancellation
The physical media used in  today’s telephony systems  requires a conversion from a  2-wire to 4-wire operation. Each
conversion calls for a hybrid. These hybrids do not perfectly  match impedances resulting in  echo. The goal of the echo
canceller is to detect and cancel this echo as quickly as possible.  The inherent challenges require  that the echo canceller not only distinguish the location of the  echo, but also be able to  distinguish the echo from double  talk and other events.

Echo Tail
The length of time over which  echo is expected to arrive is  referred to as the echo tail length.  The echo itself is normally only  about 6ms to 8ms in length and  can occur at any time during the  “echo tail”. The primary factor in  determining how much echo tail is required for a specific application is the distance and delay expected for the voice signals – the longer the delay the longer the echo tail. The delay is  measured between the hybrid location and the speaker. The maximum echo tail length in use today is 128ms although some 192ms applications exist.

Echo Quality Index (EQI)
The Telinnovation echo canceller used on the C64x+ devices will optionally include the TI proprietary Echo Quality Index
that provides an indication of the propensity for echo on any given channel. This statistic will be made available via the software’s Application Interface.

TNETV3020 image version of the echo canceller

The TNETV3020 is a 6-core 3GHz carrier infrastructure platform that provides the high density echo cancellation solution. TNETV3020 can be used to provide high density solutions for voice or video media gateway and transcoding applications. The TNETV3020 supports 204 channels of AMR or 504 channels of G.711. Once again, even higher voice channel densities are available for various customer-specific scenarios.

The TNETV3020 image version of the echo canceller supports 672 channels of line echo cancellation including Voice Quality Enhancements (VQE) and Tandem Free Operation (TFO). Even higher echo cancellation channel densities can be supported for specific customer applications. This configuration also includes the TI Echo Quality Index (EQI), which provides a measure of the propensity for echo on any given channel and is derived from TI's award wining PIQUA software.

Telinnovation echo canceller is available as either a callable function which is integrated into an OEM's framework, or as a standalone DSP image of executable code. The echo canceller is now available as a software function for the C64x and C64x+ processors. TI plans in Q3 2007, the Telinnovation echo canceller will also be available as a dedicated image on the TNETV3020.

More info: TI's Telinnovation Echo Canceller