T1 Echo Cancellers Upto 10 T1 Echo Cancellers per Chassis

Echo Cancellation

Number of Interfaces	2, 1 - Input (RJ-45) 1 - Output (RJ-45)
Line Rate	T1 - 1.544Mbps
Line Code	B8ZS, AMI (User Selectable)
Bit Rate	1544 Kbps ± 50 ppm
Conformity	G. 703
Encoding Law	µ Law as per ITU (CCITT) G.711 8 bit PCM encoding
Frame Structure	As per ITU-T G.704
Signaling	Pass-Through (signaling protocols supported) - 24B (24 voice channels) with out-of-band signaling (C7, Common Channel Signaling, SS7 (on any user selected time-slot) - 23B+D, PRI ISDN (23 voice channels + D signaling channel), - D4 Robbed-Bit and - SLC-96 signaling. - All signaling options are User Selectable / User Programmable.
PCM Sampling Rate	8000 samples / sec
Nominal Impedance	100 ohms balanced
Peak Voltage of a mark for 120W Balanced Interface	3.0 V ± 0.3 V
Peak Voltage of a space for 120W Balanced Interface	0 V ± 0.3 V
Nominal Pulse Width	244 ns
Pulse Mask	As per ITU (CCITT) rec. G.703
Output Jitter	< 0.05 UI (in the frequency range of 20Hz to 100 KHz)
Permissible Attenuation	6 dB at 1 MHz
Return Loss at: 51.2 KHz to 102.4 KHz 102.4 KHz to 2048 KHz 2048 KHz to 3072 KHz	> 12dB > 18dB > 14dB
Jitter Tolerance	As per ITU (CCITT) G.823
Loss and recovery of frame alignment	As per clause 3 of ITU (CCITT) G.732
Loss and recovery of multiframe alignment	As per clause 5.2 of ITU (CCITT) G.732
Echo Tail Cancellation	64ms Bi-Directional / 128ms Uni-Directional - User Selectable / User Programmable.
Tone Disabler	As per ITU-T G.164, G.165
ERLE (Echo Return Loss Enhencement)	>35dB (with 6dB ERL) at -10dBm0 input >65dB with NLP enabled
ERL (Echo Return Loss)	Selectable Level Options: 0, 3, 6dB
Transmit / Receive Levels (Programmable)	Selectable Level Options: -12, -9, -6, -3, 0, +3, +6, +9
Comfort Noise Insertion	User Selectable - On / Off
Local Monitoring and Control	RS232 serial interface for management through a PC COM port

Management Port Specifications

RS232 COM Port	Serial Port: 9.6kbps (Async) ASCII / VT100 / Hyper Terminal
10BaseT Ethernet	Telnet

Power Supply

Input DC voltage	-48V DC (nominal)
Range of input	-40V to -60V DC
Output voltages	+5V
Full Load Output Current	4A at +5V, (10, Echo Cancellers)
Input Voltage Reversal Protection	Provided in the Card
Over Current Protection	6A for +5V
Short Circuit Protection	Current limit - 6A. Recovers on removal of short
Under Voltage	< 4.5V
Over Voltage	5.4V to 5.6V
Efficiency at full load	>70%
Ripple at full load	<5mVrms
Spike at full load	<50mV
Power Consumption	40W (Nominal) (10, Echo Cancellers)

Power Consumption of E1 Echo Cancellers

Number of echo cancellers in use	Current (in AMPS)	Power Consumption (in WATTS)
Input Voltage = -48 volts
1 echo canceller, power supply, NMS card	0.15	6.0
10 echo cancellers, power supply, NMS card	0.825	39.6

Mechanical Specifications

Rack Mounting	Standard 19 Inch. DIN Rack
Height	133.35 mm
Depth	292 mm
Width	482 mm
Weight (Net)	7.50 Kg. (10, Echo Cancellers)

Echo Canceller Technical Specification

• Provides voice echo cancellation of up to 64ms. / 128ms.
• Conforms to ITU-T G.165 and G.168
• G.164 / G.165 disable tone detection
• Non-Linear Processor with Comfort Noise Insertion
• Narrow-Band Detector
• Eliminates long echo tail.

T1 Echo Canceller - Highlights

• Provides voice echo cancellation of up to 64ms Bi-Directional / 128ms Uni-Directional - User Selectable / User Programmable.
• Meets ITU-T G.164, G.165, G.168 (2000 / 2002) requirements for echo cancellation.
• 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,
• CCS (C6, C7),
• RBS (E&M, PLR, FXS-GS, FXO-GS, FXS-LS, FXO-LS)
• All signaling options are User Selectable / User Programmable.
• Allows digital data transmission on user-selected time-slots.
• The echo canceller supports fax / modem G.164 and G.165 (2100 Hz) tone disable.
• Carrier-grade voice quality per AT&T Voice Quality Assessment Lab.
• 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.
• T1 link by-pass on power failure. This feature helps to maintain the link integrity even in the event of power failure.
• 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 integrated independent 24-channel voice echo canceller.

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)

Redundancy

The echo canceller is equipped to offer redundant power supply (optional).

Related Links

• Echo Canceller solutions - Home Page