Xref: utzoo comp.dcom.modems:2656 comp.mail.uucp:2135 Path: utzoo!attcan!uunet!fsc2086!jim From: jim@fsc2086.UUCP (Jim O'Connor) Newsgroups: comp.dcom.modems,comp.mail.uucp Subject: Re: UUCP g stats / baud isnt bps Summary: baud definition: you asked for it :-) Message-ID: <311@fsc2086.UUCP> Date: 11 Oct 88 05:42:18 GMT References: <183@arnold.UUCP> <1988Sep20.184054.2403@utzoo.uucp> <184@arnold.UUCP> <13924@mimsy.UUCP> Organization: Filtration Sciences Corp., Chattanooga, TN Lines: 40 In article <13924@mimsy.UUCP>, chris@mimsy.UUCP (Chris Torek) writes: > >>In article <1464@netmbx.UUCP> blume@netmbx.UUCP (Heiko Blume) wrote: > >>>as far as i remember the baud rate tells you how many changes of the > >>>discrete signal levels are possible. > > >In article <13842@mimsy.UUCP> I answered: > >>Not exactly. `Baud rate' means `number of channel symbols per unit > >>time'; multiplying this by `number of bits per channel system' gives > >>the more familiar bits per unit time, typically bits per second. > > In article <210@obie.UUCP> wes@obie.UUCP (Barnacle Wes) replies: > >Nope, Heiko was right. Baud refers to the number of state changes the > >carrier makes per unit time. How this relates to the bit rate depends > >on the modulation scheme you are using (NRZ, NRZ1, diphase, etc.). > > All three of these definitions are different. While it is not my [discussion deleted] > Anyone have an official reference handy, so we can find out who is right > (and if it is Wes, why the---to me---peculiar definition of `baud')? Since you asked for it, here's something that might be considered an "official reference". From _Computer Networks_, by Andrew Tanenbaum, page 93, " The time T required to transmit the character depends on both the encoding method and the signaling speed, [the number of times per second that the signal changes it value (e.g. its voltage) [ed. or e.g. its frequency]]. The number of changes per second is measured in *baud*. A 'b' baud line does not necessarily transmit 'b' bits/second, since each signal might convey several bits." If you read "number of changes per second" as "maximum possible number of changes per second" this basically sums up the ideas presented in the three earlier definitions, with only some minor changes in the exact terminology. ------ James B. O'Connor +1 615 821 4090 x651 Filtration Sciences Corp. UUCP: uunet!fsc2086!jim 105 West 45th Street or jim@fsc2086.UUCP Chattanooga, TN 37411