July 12, 2012
Audio or voice supports applications based on sound, usually of the human voice. Primarily used in telephone communications Audio or voice signals also are used in other applications such as voice mail, radio, telemarketing, and teleconferencing. Voice quality is characterized mainly by its bandwidth used, the higher quality sound of course using the most bandwidth (Stallings, 2009). With voice signals the most effective way to manage the systems is to tie all lines together into a single system. This is done by one of two methods. The first is Private Branch Exchange (PBX). With PBX all lines are connected to an on-site switch or hub that then sends the information to the telephone system or carrier. The easiest way to tell if you are on a PBX setup is if you have to dial nine to reach an outside number then you are on a PBX setup. The next setup is a Centrex setup. With a Centrex setup all lines run directly to the service provider and are linked inside the service provider’s facility. With Centrex all lines are individual and dedicated lines so there is no press nine for an outside number. Recently there has been an introduction of Voice over Internet Protocol (VoIP). The biggest difference here is that the voice signals are being packet transferred over internet protocols. In other words your phone call or transmission is being sent over the internet to connect. This is a system that has been used by the military for its increased transmission distance and security. Data signals consist of information that can be represented by a finite alphabet of symbols. Text and data entry on your computer is an example of data signals. The values of the characters are represented by a byte or 8 bits. From the reading a typical page with one inch margins that is double spaced would have about 10,000 bits (Stallings, 2009). Video signals carry a sequence of pictures in time. Signals are...
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