Data signaling rate

• The DSR is usually expressed in bits per second. • The data signaling rate is given by \sum_{i = 1}^{m} \frac{\log_2 {n_i} }{T_i} 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. • 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, according to Hartley's law. • For parallel transmission with equal unit intervals and equal numbers of significant conditions on each channel, the DSR is (m/T)log2n; in the case of a two-condition modulation, this reduces to m/T. • The DSR may be expressed in bauds, in which case, the factor log2ni in the above summation formula should be deleted when calculating bauds. • 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 bit/s 4-phase sending modem, the signaling rate is 2400 bit/s on the serial input side, but the modulation rate is only 1200 bauds on the 4-phase output side. == Maximum rate ==

The maximum user signaling rate, synonymous to gross bit rate or data signaling rate, is the maximum rate, in bits per second, at which binary information can be transferred in a given direction between users over the communications system facilities dedicated to a particular information transfer transaction, under conditions of continuous transmission and no overhead information. For a single channel, the signaling rate is given by SCSR = \frac{\log_2{n} }{T}, where SCSR is the single-channel signaling rate in bits per second, T is the minimum time interval in seconds for which each level must be maintained, and n is the number of significant conditions of modulation of the channel. In the case where an individual end-to-end telecommunications service is provided by parallel channels, the parallel-channel signaling rate is given by PCSR = \sum_{i = 1}^{m} \frac{\log_2 {n_i} }{T_i}, where PCSR is the total signaling rate for m channels, m is the number of parallel channels, Ti is the minimum interval between significant instants for the I-th channel, and ni is the number of significant conditions of modulation for the I-th channel. In the case where an end-to-end telecommunications service is provided by tandem channels, the end-to-end signaling rate is the lowest signaling rate among the component channels. == Rates and standards ==