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E1 DCME - Voice Compression
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Description Valiant's VCL-LD, E1 DCME (Digital Circuit
Multiplication Equipment) Voice Compression Equipment provides 30, "toll
quality" voice channels using an 8:1 compression ratio, (10:1 without signaling
channel) in a bandwidth of 256kbps. Also available with fax and data modem support @
33.6Kbps data rates. This is accomplished using an advanced digital signal processor (DSP)
based Virterbi decoder with automatic voice/silence detection (VAD) and adaptive comfort
noise generation (CNG).
The interface to the local PSTN network is
ITU-T G.703, G.704 compliant E1 with signalling support for R2, CAS (ABCD) Digital
Signalling, PRI ISDN (Q.931), SS7 and C7 Signalling.
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Also
available T1, DCME (Digital Circuit Multiplication Equipment) Voice Compression Equipment
E1, VCL-LD is a natural choice for
satellite communications, digital mobile radio applications, cellular network operators,
long distance telephony service providers (including pre-paid calling card operators),
corporate customers, call-center operators wanting to optimize on expensive bandwidth
usage and offer a competitively priced, toll-quality service to their customers.
The VCL-LD, E1 DCME is equipped with a
128ms. E1 Echo Canceller (E1 echo cancellation card) which conforms to ITU-T G.165 and ITU-T G.168.
Voice compression technology has been
proven to outperform CELP, RELP, VSELP, MELP, ECELP, MP-MLQ, LPC-10 and other competitive
technologies. Numerous evaluations have shown its ability to provide performance equal to
today's digital cellular systems at under half the data rate.
The Voice Activation Detection (VAD) algorithm along with the Comfort Noise Insertion
(CNI) performs useful functions in systems trying to convert periods of silence, that
exist in normal conversation, to savings in system bandwidth. The comfort noise is intend
to give the listener the feeling that the call is still connected as, opposed to producing
absolute silence which can give the impression that the call has been dropped.
Applications
- Satellite Communications
- Digital Mobile Radio
- Cellular Telephony and PCS
- Voice Multiplexing
- Secure Communications
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- Long Distance Telephony
- Prepaid Calling Card Service
- Call Center Applications
- Rural Telephony
- Multimedia Applications
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Application
Diagrams
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Voice Quality statement for the E1,
VCL-LD™ equipment using 8:1 compression ratio (10:1 without signaling channel) for
providing better voice quality than G.729, G.726 and GSM technology. VCL-LD is a natural choice for long distance telephony service
providers (including pre-paid calling card operators), cellular operators, corporate
customers, call-center operators wanting to optimize on expensive bandwidth usage and
offer a competitively priced, toll-quality service to their customers.
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Features
- Support for multiple signaling platforms including CAS R2,
PRI ISDN, SS7 and C7 signaling.
- Echo cancellation: Echo canceller card cancels echo up to
128ms.
- E1, 30 voice channels in 256Kbps bandwidth (4, DS-0's for
voice only applications.
- E1, 30 voice channels in 384Kbps bandwidth (6, DS-0's for
voice, fax and data modem support applications.
- Ideal choice for satellite communications, digital mobile
radios, cellular network, long distance telephony (including pre-paid calling card
operators), corporate customers for linking intercity voice networks, national and
international call-center applications, and ISPs wishing to provide reliable long distance
telephony services.
- Transport over point-to-point satellite links and dedicated
leased lines.
- Minimal algorithmic processing delay.
- DTMF detection and regeneration.
- Scalable - Build as you grow.
Highlights
- Superior Voice Quality.
- E1, 30 Toll-Quality voice channels in 256Kbps of bandwidth.
- 8:1 compression ratio (10:1 without signaling channel).
- 128 ms. adaptive Echo Cancellation.
- Supports fax and data modems @ up to 33.6Kbps data rates.
- DSP based Vertibi Decoder for superior voice quality.
- 3U high, compact construction.
- Extensive set of alarms.
- User selectable clock sources.
- Forward Error Correction.
- Robust to Bit Errors & Background Noise.
- High Quality Low Data Rate Speech Coding.
- Voice Activity Detection (VAD) / Comfort Noise Insertion.
- Single and Dual Tone (DTMF) Detection and Generation.
- Modular Architecture - reduces downtime - dual port per
card.
Mechanical Specifications & Weight
| Rack Mounting |
Standard 19 inch DIN rack |
| Height |
3U (133.35 mm) |
| Depth |
260 mm |
| Width |
477 mm |
| Weight |
8.50 Kgs. |
Related Links
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