Note 1 to entry: The data signalling rate is the minimum value of the binary digit rate strictly necessary to convey the same information in the same duration as a given digital signal at a given transfer rate.

Note 2 to entry: The data signalling rate in parallel transmission is given by ${\displaystyle \sum _{i=1}^m\frac{1}{T_i}{\log }_{\text{2}}{n}_i}$, where m is the number of parallel transmission channels, T_i is the duration of the significant interval for the i-th channel, n_i is the number of significant conditions in the i-th channel.

Note 3 to entry: The unit of data signalling rate is the bit per second (bit/s).