What is the baud rate?

by: Blair Copeland (2011)

I noticed that Baud, bps, Baud Rate and Bit Rate may have been somewhat confusing.

A modem that transmits at X Baud has an effective Baud Rate of X.

The bps of a modem is the Bit Rate.

Baud (Rate) is usually the measure of signal (symbol) changes per second on an analog circuit.

Bit Rate (bps) is by definition the measure of bit per second and usually represents a digital circuit.

You can represent the Bit Rate (bps)of an analog circuit, but the discussion is more one of theory than application.

So now let us consider the question: What is the baud rate of a 1200baud modem, 2400bps modem, 56k bps modem?

A 1,200 Baud Modem has a Baud Rate of 1200.

A 1,200 Modem (V.22), getting 2 bits per baud, has a Baud Rate of 600.

A 2,400 bps connection using the maximum 2400 Baud Rate (V.32 or V.32bis) has a Baud Rate of 2400.

A 2,400 Modem (V.26bis), getting 2 bits per baud, has a Baud Rate of 1200.

A 56 Kbps Modem (V.90) has a 56 Kbps download and 33.6 Kbps upload using 8000 Baud and 3429 Baud respectively.

A 56 Kbps Modem (V.92) has a 56 Kbps download and 48.0 Kbps upload using 8000 Baud for both.