256-CHANNEL VOICE ECHO CANCELLER ZL38070 PRODUCT PREVIEW The ZL™38070 is a highly integrated VEC (voice echo canceller) that optimizes call quality in a wide range of high-density wireless and telephony equipment. The off-the-shelf device supports 256 voice channels, and cancels echo tails of 64 milliseconds or 128 ms. The VEC chip utilizes a patented NLP (non-linear processing) technology that outperforms competing devices in the presence of intense background noises. These features help ensure carrier-grade voice connections and improve subjective voice quality by removing echoes, clicks, and hisses caused by the user environment, network conditions and round-trip delays in speech signals. The device uses an efficient architecture that reduces board space and development resource requirements. &$( &DIP 3FNPWBM &$( 4JHOBM8JUI 3FTJEVBM&DIP Fast re-convergence on echo path changes Fully programmable convergence speeds per-channel improves performance during double-talk Flexibility and Ease-of-Use /PO-JOFBS 1SPDFTTPS 4JHOBM 8JUIPVU&DIP 4JHOBM 1$.0VUQVU 4USFBNT XJUI"EWBODFE /PJTF.BUDIJOH %JTBCMFUPOF/BSSPX#BOE %PVCMF5BML 1BUI$IBOHF*OTUBCJMJUZ 3FGFSFODF 1$.*OQVU 4USFBNT 3FGFSFODF4JHOBM "" %% Each ECG offers parallel DSP processing without resource sharing limitations Compatible pin-outs simplify system upgrades Standards Compliant $IBOOFMTBUNTPS$IBOOFMBUNTPS#JEJSFDUJPOBM .JDSPQSPDFTTPS"DDFTTBOE$POUSPM Configurable to allow simultaneous operation of dual channel ECG (echo canceller group) at 64 ms, bidirectional 64 ms or 128 ms Low-power operation (4.6 mW per channel) with independent powerdown mode (%FUFDUPST "EBQUJWF 'JMUFS 3FGFSFODF 1$.0VUQVU 4USFBNT Full band convergence allows multiple echo reflection cancellation Protection against narrowband signal divergence in high echo environments or in the presence of DTMF or other tones &$(O $IBOOFM&DIP$BODFMMFS(SPVQ 4JHOBM 8JUI&DIP NLP with adaptive suppression threshold and spectrally matched comfort noise injection removes residual echo and minimizes switching effects Adjustable signal gain/loss improves ERL performance and flexibility for system gains $IBOOFM&DIP$BODFMMFS 4JHOBM 1$.*OQVU 4USFBNT High-Density VEC with Advanced Noise Matching 5FTU1PSU ITU-T G.168 (2000), G.168 (2002) and ITU-T G.165 Fax/modem G.164 2100 Hz Tone Disable Streamlines AT&T equipment certifications Applications Packaging and Availability Media access gateways 535-ball BGA T1/E1 multi-channel echo cancellation pools In volume production Wireless CDMA/GSM networks Interactive voice response systems Customer Support The ZL38070 VEC is supported by Zarlink’s network of in-house field application and design engineers. Evaluation boards with full design and applications documentation are available. 256-CHANNEL ZL38070 VOICE ECHO CANCELLER APPLICATION 3G Mobile Switching Centre The ZL38070 high-density VEC improves voice quality in the wireless telephony network infrastructure, where longer signal processing and transmission delays may emphasize voice echo issues. These problems are further compounded by excessive background noise that impacts call quality. The device also improves performance during double-talk conditions. Zarlink’s algorithm adjusts to a slow convergence speed once double-talk is detected. The convergence speed can be slowed by as much as 128 times that of the fast convergence mode to dramatically improve stability. The ZL38070 reduces the effects of this delay by using a patented NLP software algorithm that includes several features to improve voice quality. The device offers an ideal solution for equipment such as a 3G Voice Gateway in a 3G Mobile Switching Center, as illustrated below. The VEC provides several advantages over alternative integrated voice/packet processor and DSP approaches. Most integrated processors encounter latency problems, while DSP solutions compromise size, cost and performance once density increases to more than 32 channels. When removing residual echoes, the ZL38070 uses a patented software algorithm that injects spectrally matched “comfort noise” onto the line to eliminate noise gating when echoes from a POTS (plain old telephone system) are cancelled. Superior noise matching capabilities offered by Zarlink’s high-density VEC ensures carrier grade voice quality throughout the wireless network, even in high-noise situations. In comparison, less effective noise matching results in background noise on the line that sounds “choppy” to cell phone users. The ZL38070 consumes only 4.68 mW of power per-channel. Individual blocks can be turned off when not all channels are in use to further reduce power consumption. In a mobile switching center, where overall power consumption is a critical design concern, the ZL38070 VEC delivers power efficiency advantages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nformation relating to products and services furnished herein by Zarlink Semiconductor Inc. or its subsidiaries is believed to be reliable. The products, their specifications, services and other information appearing in this publication are subject to change by Zarlink without notice. ZARLINK, ZL, and the Zarlink logo are trademarks of Zarlink Semiconductor Inc. © 2004, Zarlink Semiconductor Inc. All Rights Reserved. Publication Number PP5887 www.ZARLINK.com