G.168 Plus™ Packet EC
World
class Echo Canceller 
C64x+
Packet EC
Adaptive Digital's echo canceller (G.168 Plus Packet EC) is able to handle round-trip delays of 512 milliseconds. Furthermore, our echo canceller is packet-loss aware and is able to mitigate the specific effects that packet loss has on echo cancellation in the VoIP network.
Packet Loss: If an echo canceller is placed on the opposite side of a packet network with respect to the hybrid, a lost packet causes an interruption in the echo path. This can cause an echo canceller to diverge.
Adaptive Digital’s echo canceller is offered in three variants, which are compared by feature set in the following table.
| Feature | G.168 LEC | G.168 NEC | G.168+ Packet EC |
| Maximum Tail Length | 32 msec | 128 msec | 512 msec * |
| Tandem Free Operation * | X | X | X |
| Packet Loss Concealment * | -- | -- | X |
| PCM Slip Correction * | -- | X | X |
| Dynamic* NLP | X | X | X |
| Comfort Noise Generator | X | X | X |
| Rapid Convergence | X | X | X |
| Automatic Tail Search | X | X |
|
| Cancels multiple reflectors | X | X | X |
| Convergence Monitor * | X | X | X |
| Tone Disabler | X | X | X |
| SS7 Tone Detection | -- | X | X |
| Double-talk Detection | X | X | X |
| Stationary Signal Detector | X | X | X |
| Pre-NLP Signal Available* | X | X | X |
| Split Pre- and Post- Processing * | X | X | X |
| Handles Residual Acoustic Echo | X | X | X |
| eXpress DSP™ compliant | X | X | X |
| Functions are “C” callable | X | X | X |
| User Configurable Parameters | X | X | X |
* indicates that this feature is an enhancement beyond the G.168 recommendation
C64x
All Memory usage is given in units of byte.
Tail Length |
MIPS (Peak) |
Program Memory |
Data Memory |
Per-Channel Data Memory |
8 msec. tail |
1.6 |
18208 |
722 |
1086 |
16 msec. tail |
2.7 |
18208 |
850 |
1478 |
32 msec. tail |
3.2 |
18208 |
1106 |
2262 |
64 msec. tail |
3.6 |
23712 |
2540 |
3502 |
128 msec. tail |
3.7 |
23712 |
3756 |
5240 |
256 msec. tail |
4.1 |
23712 |
5738 |
7710 |
384 msec. tail |
4.5 |
23712 |
7940 |
10426 |
512 msec. tail |
5.0 |
23712 |
10600 |
13598 |
NOTE: Characterized with PCM Slip Correction disabled. Tail lengths of 256, 384, & 512 msec. are only supported in the G.168 Packet EC.
With G.168+/Packet EC, Adaptive Digital strives to meet the current and future requirements of service providers, system developers, and end-equipment manufacturers bringing superior voice quality to speech-based applications. By continually evolving their echo cancellation algorithm, Adaptive Digital strives to increase the differentiation between their world class EC and those of their competitors.
Adaptive Digital’s G.168+ packet echo canceller software currently runs on several platforms including: Texas Instruments Incorporated’s (TI) high-performance TMS320C6000™ DSP and intel’s x86 line of processors. The software is offered in library format, fixed point C-reference code, and as part of Adaptive Digital’s Application Specific Signal Processing chips.
Contact us f or more information on the Echo Canceller algorithm, one
of our products or custom solutions, contact us at 610-825-0182
