ADSL : Asymmetrical Digital Subscriber Line. Refers to a pair of modems connected by a copper line that yields asymmetrical transmission of data.

Amplifier : Electronic devices that strengthen a signal as it passes along a communications channel.

Analog Signal : A wave shaped electrical symbol, which continuously changes with respect to size and shape depending on the information source. Differences in volume, voice and pitch are a result of signal variations.The selection, design, and interconnection of the hardware of a computer system.

Archiving : A method of transferring information created during operations into a more permanent form. Systems vary from manual backups, through periodic transfer to audio cassettes, to real-tune storage onto WORM (Write Once Read Many) disks.

Asynchronous Communication : Refers to systems of communication where there is a lapse in time from when a message is sent and when it is received.

Audio-teleconferencing :Two way communications between multiple people at various locations.

Authentication : A method of verifying the identity of the person sending or receiving information by use of passwords, keys and other automated identifiers.

Automated Data Collection : The direct transmission of physiological information from monitoring devices to either a bedside display system or a computer-based patient record.