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Bhumika
International Inc. offers the industry's most
compact 8, T1 echo canceller with Voice Quality Enhancement (VQE) solution in 19 inch, 1U (44mm
height) chassis, with tail-displacement feature from 0ms. to 512ms - user
selectable. Echo cancellation on each channel is 128ms. bi-directional. The 8 port T1 echo
canceller solution offers a unique, user definable echo-tail displacement between 0ms. to
512ms. on the return path to cancel echo-tails, both at the near-end and the far-end, in
the most demanding conditions. E1 echo cancellers are also
offered and available.
Bhumika offers echo cancellation and voice
quality enhancement solutions for the following network
situations:
- Wireline
- Wireless
- Satellite
- International Gateway
- IP Gateway
The echo canceller solutions are also ideal
for long distance telephony, GSM, CDMA, TDMA, VoIP, satellite and radio communication
applications.
The echo canceller equipment is compliant to
ITU-T G.164, G.165, G.168 (2000 / 2002) requirements for echo cancellation. The echo
canceller solutions offers carrier-grade voice quality per AT&T Voice Quality
Assessment Lab. Echo cancellation on each channel is 128ms. Bi-Directional with user
definable echo-tail displacement between 0ms. to 512ms.
Type of T1 Echo Canceller offered -
8 T1 ports per 19 inch, 1U (44mm) chassis
T1 echo canceller: 128ms. bi-directional. T1 Inputs and
Outputs are balanced 100 Ohms, RJ-45
Key
Highlights of the Bhumika T1 Echo Canceller solution
- Bhumika offers the industry most compact 8, E1 (and T1) Echo
Cancellers and Voice Quality Enhancement (VQE) solution. T1 (or E1) echo cancellers in a
1U (44mm) high chassis – industry’s smallest footprint.
- Ideally suited for GSM Networks to eliminate "back
ground noise" to enable GSM Networks to function at Half-Rate (HR) thereby doubling
spectrum usage in GSM networks.
- 128 ms. bi-direction echo cancellation with echo-tail
displacement from 0ms. to 512ms.
- Programmable echo-tail displacement from 0ms. to 512 ms.
- Echo-tail displacement allows user to program a delay
off-set on return path and user can cancel near-end and far-end echo from single
installation.
- Cancels near-end and far-end echo from single installation
- Echo Cancellation on each channel is 128ms. bi-directional.
- Compliant to ITU-T G.164, G.165, G.168 (2000/2002)
requirement for echo cancellation.
- User programmable signaling options - 24B (24 Voice
Channels) with out-of-band signaling (C7 / SS7 Signaling on any user selected time-slot),
23B+D, PRI ISDN (23 Voice Channels+D Signaling Channel), D4 Robbed Bit Signaling.
- Electrical echo-cancellation resulting from network delays
and delays arising due to complex voice compression algorithms in hybrid PSTN and long
distance networks.
- Acoustic echo-cancellation required for mobile networks for
canceling echo-tails that originate from cellular hand-sets poorly designed acoustic
feedback.
- Background Noise Reduction and Auto Voice Level Control
(VQE, Voice Quality Enhancement features) required for reducing background noise from
calls originating from crowded public places or other noisy environments and maintaining a
uniform voice level in a network. Improves voice quality.
- User programmable data channel(s)
- Remote access through telnet
- 8 T1 (or E1) echo cancellers in a 1U (44mm.) high chassis -
industry's smallest footprint
- Applications include wireline, wireless, satellite,
international / long distance gateways, DCME and radio communication networks
- Usable in telecommunications systems worldwide.
Question. What is
tail-displacement?
Answer: Tail-displacement is
an important feature used in bi-directional echo-cancellation, to
make it effective and useful for bi-directional echo-cancellation.
Explanation: Bi-directional
echo-cancellers have the capability of canceling echoes in BOTH
directions (on the Transmit as well as the Receive paths), by
installing them at a single location. Bi-directional
echo-cancellers can be installed at a single location, either the
Near-End or the Far-End, and used to cancel BOTH Near-End and
Far-End echo-tails, from a single installation.
Usually, satellite links and intercontinental VoIP circuits have
fixed network delays which exceed the capabilities of commonly
available (192ms) echo-cancellers for bi-directional
echo-cancellation, thus making them unsuitable for bi-directional
echo-cancellation.
Example: An inter-continental
satellite or a VoIP link may have a fixed end-to-end round-trip
delay of 300ms, thereby rendering all commonly available
echo-cancellers, with even 192ms echo-cancellation capabilities,
in-effective for bi-directional echo-cancellation.
Using the Tail-Displacement feature, the User may offset and
account for the fixed round-trip network delay on the return path
so that the echo-cancellation window on the return-path is shifted
by 300ms., so as to allow the bi-directional echo-canceller to
function effectively in BOTH directions and to cancel BOTH
Near-End, as well as the Far-End echo-tails on the return path,
even if the echo-canceller is installed at the Near-End in a given
network..
Tail-displacement allows the user to program a delay off-set on
the return path, so that the User may cancel both near-end and
far-end echo-tail with a single Echo Canceller installation. The
tail-displacement allows the user to compensate for the fixed
network delays on the return path of the echo-tail, so that the
user can effectively cancel, both near-end and far-end echoes
using a single Echo Canceller without being limited by the fixed
end-to-end delay of that network link.
Bhumika's Echo-Canceller has a user programmable "tail-end
displacement" from 0ms. to 512ms.
This feature allows the use of a single Echo Canceller
installation to cancel echo-tails in both directions over
inter-continental satellite or VoIP links where the fixed network
delays are excessive (beyond and in excess of (example) 192ms.
echo-cancellation capability of the most commonly sold
bi-directional Echo Canceller solutions).
Question: My Network has a total of
300ms. end-to-end delay. How can I use a 128ms. bi-directional
echo canceller to cancel, both, near-end and far-end echoes?
Answer: The use of the
"programmable tail-displacement" feature in our Echo Cancellers
allow the user to cancel echoes on the return path even if the
network delays exceed 128ms.
The fixed network delay shall be calculated ascertained and
programmed as the "tail-displacement" on the return path. This
shall allow the user to use a single Echo Canceller to cancel
echoes, bi-directionally, even if the total network end-to end
delay is in excess of 300ms.
The Bhumika 128ms., bi-directional Echo Canceller solution, equipped
with a user programmable "tail-displacement" feature is superior
than a simple single 192ms. bi-directional Echo Canceller solution
for canceling both near-end and far-end echoes, even if the fixed
round-trip network delays exceed 300ms (please see the example
above).
T1 Echo Canceller - Highlights
- Provides voice echo cancellation of up to 128ms
Bi-Directional for 8 T1 echo cancellers
- Meets ITU-T G.164, G.165, G.168 (2000 / 2002) requirements
for echo cancellation
- Custom user definable echo-tail displacement between 0ms. to
512ms. This allows the user to cancel echo in both directions (near-end and far end), even
in most difficult conditions i.e. excessive transmission delays that are common on VoIP
networks and satellite links
- Voice Quality Enhancement:
- Removes background noise
- Automatic level control (maintains VF levels)
- Signaling protocols supported:
- 24B (24 Voice Channels) with out-of-band signaling (C7 / SS7 Signaling on any user
selected time-slot),
- 23B+D, PRI ISDN (23 Voice Channels+D Signaling Channel),
- D4 Robbed Bit Signaling.
- All signaling options are User Selectable / User Programmable.
- Allows digital data transmission on user-selected
time-slots.
- T1 link by-pass on power failure. This feature helps to
maintain the link integrity even in the event of power failure
- The echo canceller supports fax / modem G.164 and G.165
(2100 Hz) tone disable
- User selected clock / synchronization option - Internal,
External and Loop-Timed clock
- Stratum 3e clock for stable Internal clock / holdover clock
in the event of failure of any of the selected clock sources
- Remote access through telnet over LAN / TCP-IP link
(10/100BaseT)
- Local access through COM port (RS232 serial port)
- Easy to use text based CLI commands for management and
configuration
- Adjustable gain/loss settings on all channels. Provides the
user the flexibility to adjust and optimize the voice, transmit and receive levels.
- Non-Linear Processor with Comfort Noise Insertion
- Option for user to select voice echo cancellation or
digital-data transmission selectively on each time-slot for selective echo cancellation.
This feature allows the user to use selected time-slots for data transmission to enable
digital data / CCS signaling transmission.
- Transmission (data mode), while keeping the echo
cancellation "ON" on the remaining time-slots (voice mode), on which echo is
required to be cancelled.
- Ensure echo canceller maintains excellent performance at all
times in presence of tones or signals including DTMF tones.
- Fully independent 8 T1 (or E1) echo canceller
Unique T1 Echo Canceller Feature:
USER PROGRAMMABLE TAIL DISPLACEMENT: User
definable echo-tail displacement is selectable between 0ms. to 512ms. on the return-path.
This feature allows the user to cancel echo-tails in BOTH directions (both near-end and
far-end echo tails), even in most demanding conditions that are common on VoIP networks
and satellite links.
USER PROGRAMMABLE SIGNALING OPTION: The T1 echo
cancellers supports the following signaling protocols: Signaling protocols supported: 24B
(24 Voice Channels) with out-of-band signaling (C7 / SS7 Signaling on any user selected
time-slot), 23B+D, PRI ISDN (23 Voice Channels+D Signaling Channel), D4 Robbed Bit
Signaling. All signaling options are User Selectable / User Programmable. Allows digital
data transmission on user-selected time-slots.
USER PROGRAMMABLE DEDICATED DATA CHANNELS: The User
my specify / define the dedicated data channels so that they are ALWAYS and COMPLETELY
BYPASSED from the echo-cancellation circuitry - leaving those specifically assigned
dedicated time-slots for digital data transmission (including video transmission).
The T1 echo canceller supports 2100 Hz fax / analog data
modem tone detection and echo canceller disabling on all channels.
Background Noise Reduction and Auto Voice Level Control
(VQE, Voice Quality Enhancement features) required for reducing background noise from
calls originating from crowded public places or other noisy environments and maintaining a
uniform voice level in a network. Improves voice quality.
Signaling Support:
The T1 echo cancellers supports the following
signaling protocols: 24B (24 Voice Channels) with out-of-band signaling (C7 / SS7
Signaling on any user selected time-slot), 23B+D, PRI ISDN (23 Voice Channels+D Signaling
Channel), D4 Robbed Bit Signaling. All signaling options are User Selectable / User
Programmable. Allows digital data transmission on user-selected time-slots.
Fault Recovery:
The echo canceller equipment offers fault
recovery feature. It offers automatic by-pass upon power-supply failure (i.e. it offers T1
circuit by-pass in the event of power supply failure).
Remote Monitoring and Control
- Remote access through telnet over LAN / TCP-IP link
(10/100BaseT)
- Local access through COM port (RS232 serial port)
Applications for
the T1 Echo Cancellers
Datacomm
Applications
- Voice Over Frame Relay
- Voice Over ATM
- Voice Over Internet / LAN
Central Office and PBX Applications
Voice Over ATM
Applications
Satellite
Communications Applications
- Digital Circuit Multiplication Equipment (DCME)
Wireless
Applications
Voice Over Frame
Relay, ATM Applications
Application
Diagrams for the T1 Voice Echo Cancellers
- Application Diagram - 128ms Bi-Directional T1 Echo cancellers.
Others Echo
Cancellers Solutions:
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