T1,
Voice Compression (DCME)
| Product
Description VCL-LDTM
T1, DCME (Digital Circuit Multiplication Equipment) Voice Compression
Equipment provides 24, "toll quality" voice channels using an 6:1
compression ratio (8:1 Compression Ratio without the signaling channel),
in a bandwidth of
256kbps. |
 |
| 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 T1 with signaling support for PRI ISDN (Q.931), SS7 / C7, Common Channel
Signaling.
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.
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
- Secure Communications
- Cellular Telephony and PCS
- Voice Multiplexing
|
- Voice Mail
- Long Distance Telephony
- Prepaid Calling Card Service
- Call Center Applications
- Rural Telephony
|
|
Features |
Highlights |
- Support for multiple signaling platforms including CAS
R2, PRI ISDN and SS7 Signaling
- Echo cancellation: Echo canceller card
cancels echo up to 128ms
- T1, 24 voice channels in 256Kbps bandwidth (4, DS-0's :-
includes signalling channel @ 64Kbps)
- Ideal choice for satellite
communications, digital mobile radios, cellular network, long distance
telephony service providers (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 service to their customers
- Modular Architecture - reduces
downtime - dual port per card
- Scalable - Build as you grow
- Transport over point-to-point
satellite links and dedicated leased lines
|
- T1, 24 Toll-Quality voice channels in
256Kbps of bandwidth
- 6:1 compression ratio (8:1 without
signaling channel)
- 128 ms. adaptive Echo Cancellation
- DSP based Vertibi Decoder for superior
voice quality
- 3U high, compact constructio
- Extensive set of alarms
- User selectable clock sources
- Forward Error Correction
- Superior Voice Quality
- 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
- Minimal algorithmic processing delay
- DTMF detection and regeneration
|
VCL-LD, T1 DCME (Digital Circuit
Multiplication Equipment)
Shelf Description:
The VCL-LD, T1 DCME (Digital Circuit Multiplication
Equipment) is a 3U, 19 Inch Shelf, fitted with a backplane that provides rear access of
all external interfaces. The T1 interface, power input, alarm extention are all accessed
from the backplane.
VCL-LD, T1 DCME (Digital
Circuit Multiplication Equipment)
Front View of the Shelf
| Front View (Left to
Right) |
Card Details |
Part No. |
| Slot 1 |
PS, Power Supply Card |
VCL-LD-110 |
| Slot 2 to Slot 5 |
VCC, Voice Compression Card |
VCL-LD-220 |
| Slot 6 |
DS-0, DS-0 Card |
VCL-LD-230 |
| Slot 7 to Slot 10 |
VCC, Voice Compression Card |
VCL-LD-220 |
| Slot11 |
DS-0, DS-0 Card |
VCL-LD-230 |
| Slot1 to Slot15 |
VCC, Voice Compression Card |
VCL-LD-220 |
| Slot 16 |
DS-0, DS-0 Card |
VCL-LD-230 |
| Slot 17 |
VCE, T1 Interface Card |
VCL-LD-240 |
| Slot 18 |
EC, Echo Canceller Card
(128ms Echo Cancellation) |
VCL-EC128-T1 |
- Application Diagrams
Others Links
Technical specifications are subject to change without
notice.
All brand names and trademarks are the property of their respective owners.
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