31 Segovia, San Clemente, CA 92672 (949) 369-3867 •
[email protected] This file can be found on the TEC website at http://www.tecweb.org/eddevel/telecon/glossary.pdf Telecommunications Glossary from "A Technical Guide to Teleconferencing and Distance Learning," 3rd edition A 2 N 59 B 7 O 62 C 13 P 64 D 22 Q 70 E 28 R 71 F 31 S 74 G 36 T 83 H 38 U 88 I 42 V 90 J 46 W 93 K 48 X 95 L 49 Y 95 M 52 Z 95 Telecommunications Glossary/1 A Access Channels: Dedicated channels giving nondiscriminatory access to a local cable system by the public, government agencies or educational institutions. ACCUNET Switched Digital Services: High-speed dial-up digital data services offered by AT&T for full duplex digital transmission at speeds of 56, 64, 384 and 1536 kbps. Uses include data, voice and video services. Acoustic Coupler: A device that allows a conventional telephone handset to feed its signal into a modem, as opposed to direct couplers, which feed the modulated/demodulated signal directly into the phone line. Acoustic Echo Canceller: All speakerphones have some form of adaptive echo canceller that produces a synthetic replica of the potential echo to subtract from the transmit audio. Most units have a center clipping echo suppresser to remove the residual echo from the transmit signal. The goal of the acoustic echo canceller is to reduce the amount of direct and reverberant loudspeaker coupling to the microphone to prevent echo. To achieve this, the algorithms used in today's devices require an audio system that is feedback stable.