T1 Echo Cancellers

Features and Highlights

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)

Unique T1 Echo Canceller Features:

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.

Applications for the T1 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.

Related Links

• Echo Canceller solutions - Home Page