What Is Baud (Bd)?

"Baud" isn't just an excellent word we made up. It's the name of a unit of measurement that shows how many signaling elements or symbol changes (electronic state change) are sent per second in a line code or a digitally modulated signal. It's not the measure of data transfer speed but the measure of modulation. It should be distinct from the gross data transfer rate, expressed in bits per second. Although the two are related, they are not equal. So what does this mean for you? Well, if you're trying to increase your Baud rate—by changing your line code or digitally modulating your signal, you might see an improvement in data transfer speed! Baud (Bd) is named after Emile Baudot, a French electrical engineer who invented the first teleprinter in 1870. A data transmission unit shows how many signaling elements or symbol changes (electronic state change) are sent per second in a line code or digitally modulated signal. Baud is usually expressed in terms of symbols per second. One symbol corresponds to a single change in the state of the communication channel. Thus, the baud rate equals the number of characters per second. Each state change involves one byte in a communication system with eight possible states. Therefore, there are eight bits per symbol. Since there are eight symbols per second, the baud rate equals eight bits per second. If you've ever read a textbook or Wikipedia article on the Baud rate, you might be surprised to learn that it has nothing to do with bits per second (BPS). Baud and bit rate differ because they don't represent the same thing. Baud measures how many state changes occur in a signal per second, while bit rate measures how many bits are transmitted simultaneously. So if you're sending two bits per symbol, your bit rate will be double your baud rate.