Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site redwood.UUCP Path: utzoo!watmath!clyde!bonnie!akgua!sdcsvax!sdcrdcf!hplabs!hpda!fortune!redwood!rpw3 From: rpw3@redwood.UUCP (Rob Warnock) Newsgroups: net.physics Subject: Re: purplexing multiplexing question.... Message-ID: <175@redwood.UUCP> Date: Wed, 27-Feb-85 18:18:59 EST Article-I.D.: redwood.175 Posted: Wed Feb 27 18:18:59 1985 Date-Received: Sun, 3-Mar-85 05:26:42 EST References: <2117@drutx.UUCP> <624@mhuxt.UUCP> Organization: [Consultant], Foster City, CA Lines: 29 > can anyone explain the difference between "time-division" and > "frequency-division" multiplexing in laymans' terms? > mail: ihnp4!drutx!grm [then follows a nice reply by Jeff Sonntag] Just to complete the orthogonalization, let us not forget "space-division" multiplexing, which allows multiple communications to proceed at the same time on the same frequencies, but at different places. Examples are: multiple wires in a bus, multiple T-1 trunks between COs, tight-beam point-to-point microwave or laser links, and (very important!) multiple lanes in a road. ;-} (Polarization-division multiplexing, widely used in satellite transmission, is generally viewed as a form of space-division, but can be thought of as frequency-division by choosing a suitable definition of "vector frequency".) Note that highways exhibit both time- and space-division muxtiplexing, but as the discrete nature of the objects carried thence implies an extremely wide spectrum in the DeBroglie-wave representation, frequency- division cannot be usefully employed while maintaining the identity of the wave packets. Of course, from time to time some unfortunate experimenters do (unsuccessfully) try... ;-} ;-} Rob Warnock Systems Architecture Consultant UUCP: {ihnp4,ucbvax!dual}!fortune!redwood!rpw3 DDD: (415)572-2607 USPS: 510 Trinidad Lane, Foster City, CA 94404