In survey after survey potential and actual users of wireless communications indicated that voice quality topped their reasons for selecting a specific service provider. While providers have been well aware of this key component powering their offering, they have not always been certain as to the specific methodology, resolution elements, equipment type, architecture, trade-offs, and rate of return on their particular investment that elevate the perceived voice-quality performance in their network.

It is only natural that voice quality in wireless networks has become a key differentiator among the competing service vendors. Network operators, network infrastructure planners, sales representatives of equipment vendors, their technical and sales support staff, and students of telecommunications seek information and knowledge continually that may help them understand the components of high-fidelity communicated sound.

Throughout the 1990s applications involving voice-quality enhancements, and specifically echo cancelation, have induced fresh inventions, new technology, and startling innovations in the area of enhanced voice performance. The initial echo canceler (EC) product implementations existed for about a decade before a diverse array of voice-quality enhancement realizations emerged to meet the evolving needs of digital wireless communications applications.

Early EC implementations were limited to very long distance (e.g., international) circuit-switched voice and fax applications where echo was perceived (in voice conversations) due to delays associated with signal propagation. The EC application soon expanded beyond strictly very-long-distance applications as further signal processing and dynamic routing along the communications path added delay to end-to-end voice transport.