The aggregate rate at which data pass a point in the transmission path of a data transmission system . 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, n i is the number of significant conditions of the modulation in the I -th channel , and T i 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 )log 2 n ; 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 )log 2 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 log 2 n i 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.