Note 1: The DSR is usually expressed in bits per second.
Note 2: The data signaling rate is given by where m is the number of parallel channels, ni is the number of significant conditions of the modulation in the I-th channel, and Ti is the unit interval, expressed in seconds, for the I-th channel.
Note 3: For serial transmission in a single channel, the DSR reduces to (1/T )log2n ; with a two-condition modulation, i.e. , n =2, the DSR is 1/T .
Note 4: For parallel transmission with equal unit intervals and equal numbers of significant conditions on each channel, the DSR is (m /T )log2 n ; in the case of a two-condition modulation, this reduces to m /T .
Note 5: The DSR may be expressed in bauds, in which case, the factor log2ni in the above summation formula should be deleted when calculating bauds.
Note 6: In synchronous binary signaling, the DSR in bits per second may be numerically the same as the modulation rate expressed in bauds. Signal processors, such as four-phase modems, cannot change the DSR, but the modulation rate depends on the line modulation scheme, in accordance with Note 4. For example, in a 2400 b/s 4-phase sending modem, the signaling rate is 2400 b/s on the serial input side, but the modulation rate is only 1200 bauds on the 4-phase output side.
Source: from Federal Standard 1037C