T1 Echo Cancellers - 8 T1 Echo Canceller with VQE

Features and Highlights

Key Highlights of the Valiant T1 Echo Canceller solution

• Valiant offers the industry most compact 8, 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 896ms.
• Programmable echo-tail displacement from 0ms. to 896 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.
• User programmable signaling protocol 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,
• 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.
• Compliant to ITU-T G.164, G.165, G.168 (2000/2002) requirement for echo cancellation.
• 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.

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 896ms. 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,
• 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.
• 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 896ms. 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. - 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.

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.

Signaling Support

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,
• 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.

Voice Quality

• Acoustic Echo Control (AEC)
• Adaptive Noise Reduction (ANR)
• Automatic Level Control (ALC)
• Adaptive Listner Enhancement (ALE)

Fault Recovery

The echo canceller equipment offers fault recovery feature. It offers automatic by-pass upon power-supply failure (i.e. it offers E1 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 E1 Echo Cancellers

• Wireless: GSM, CDMA, TDMA, PCS, and Cellular Base Stations.
• Digital Circuit Multiplication Equipment (DCME) : Satellite Communications and Multiplexers.
• PCS, cellular, mobile, and digital cordless wireless systems.
• PBX and central office systems.
• Datacomm: Voice Over Frame Relay, Voice Over ATM, and Voice Over Internet.
• Voice over ATM, Frame Relay or packet switching systems and fax transmissions.
• Central Office and PBX: Network Trunks, Echo Canceller Pool, Common Equipment and Audio Conferencing Bridges
• Voice over datacomm including voice over Internet (VoIP), voice over ATM (VoATM), and voice over Frame Relay (VoFR).

Datacomm Applications

• Voice Over Frame Relay
• Voice Over ATM
• Voice Over Internet / LAN

Central Office and PBX Applications

• Network Trunks
• Echo Canceller Pool
• Common Equipment
• Audio Conferencing Bridges

Voice Over ATM Applications

• A multi-channel echo canceller resource or pool is shared among many channels to reduce cost
• Echo cancellation is done at a DS0 level

Satellite Communications Applications

• Digital Circuit Multiplication Equipment (DCME)

Wireless Applications

• GSM, CDMA, TDMA
• Digital Cordless and Cellular Basestations

Voice Over Frame Relay, ATM Applications

• Frame Relay and ATM routers and switches introduce large, variable, and unpredictable delays.
• Echoes from the Public Switched Telephone Network (PSTN) in combination with the delays from Frame Relay and ATM equipment yield objectionable speech quality.

Application Diagrams for the T1 Voice Echo Cancellers

• Application Diagram - 128ms Bi-Directional T1 Echo cancellers

Related Links

• Echo Canceller solutions - Home Page