(1) The number of bits of Data transmitted over a phone line per second. You can usually figure how many characters per second you will be transmitting, in Synchronous communications, IF you divide the bit rate by ten. The total bits transmitted will depend on re-transmissions, which depends on the Noise of the line, etc. (2) The number of bits of data transmitted per second over a communications link. This usually represented as BPS (bps) with Kbps (Kbps) standing for kilo bits per second (1000 BPS) and Mbps standing for mega bits per second (million BPS) and GBPS standing for giga bits per second (billion BPS) etc. (3) The speed of binary data transmitted, equal to the number of Digital bits sent per second. For EAS, 6250/12 = 520.83; or 2083.33 - 1562.5 = 520.83.