Real-time implementation and performance of a 16 kb/s low-delay CELP speech coder

Video on phone lines: technology and applications

“…Separate digitalization of the different transmission segments have generated some interesting issues regarding interworking among different digital and analog facilities, for instance, the need to consider analog links' echo effects in determining the allowable delay in a (digital) speech codec and the need to accommodate both speech and voiceband data in the design of a "speech coding" algorithm for interoffice transmission application [ 11- [4]. These concerns will remain for some time.…”

“…Over the years, several transmission rates have been selected for technological study and standards deliberation. Of them the most widely known is perhaps the 1 4 4 We also note that, since fixed-rate access inevitably underutilizes the loop plant's potential unless we tailor the transmission rate for each individual line, some have explored the idea of adaptive transceivers which can dynamically find the maximum rate a loop will support [28].…”

“…It is expected that a full NTSC video quality can be achieved with a bit rate of [4][5][6] Mb/s by using the MPEG2 standard. Although the needed bandwidth may eventually be provided by fiber, the current penetration of fiber in the feeder plant (primarily in conjunction with the deployment of digital loop carriers in the residential environment) is still not large enough to immediately provide ubiquitous service.…”