summer@brahma.trl.oz.au (Mark Summerfield - Switching) (03/14/91)
Users of PABX systems may well be familiar with the conferencing facilities they frequently provide, whereby three (or sometimes more) parties may take part in a conversation. I am investigating providing this function in a digital phone, for three party only. Effectively, in each phone there may be two incoming digital streams, which will be combined and fed to the earpiece. The question is: how should this combination be done? I have seen schemes in which the "loudest" speaker is determined, and others excluded. This seems inappropriate to me, although it is an option. Summing the inputs seems simple in practice, however it is not obvious how effective this is. Is overflow a problem in real life, or does the random nature of the signals, and the fact that practical conversations have only one speaker at a time, prevent it from occurring to any significant degree? What other problems may occur? I am hoping to find examples of real applications of this, but am having trouble finding papers/books which refer to this subject. Finding appropriate keywords seems to be a problem. Can anyone point me in the direction of any work which has been published in this area. Actual implementations in either software or hardware of multi-party conferencing by any technique are of particular interest. Thanks to anyone who can help, Mark. ------------------------------------------------+-----------------------------+ Mark Summerfield, Telecom Research Laboratories | "A witty saying proves | ACSnet[AARN/Internet]: m.summerfield@trl.oz[.au]| nothing." -- Voltaire | Snail: PO Box 249, Clayton, Vic., 3168 +-----------------------------+