Info Tech Guide

The term bit rate is a synonym for data transfer rate (or simply data rate). Bit rate seems to be used more often when discussing transmission technology details and data transfer rate (or data rate) when comparing transmission technologies for the end user. Bitrate describes the rate at which bits are transferred from one location to another. In other words, it measures how much data is transmitted in a given amount of time.

Bitrate can also describe the quality of an audio or video file. For instance, an MP3 audio file that is compressed at 192 Kbps will have a greater dynamic range and may sound slightly more clear than the same audio file compressed at 128 Kbps. This is because more bits are used to represent the audio data for each second of playback. Similarly, a video file that is compressed at 3000 Kbps will look better than the same file compressed at 1000 Kbps. Just like the quality of an image is measured in resolution, the quality of an audio or video file is measured by the bitrate.

In digital communication systems, the gross bitrate, raw bitrate, data signaling rate or uncoded transmission rate is the total number of physically transferred bits per second over a communication link, including useful data as well as protocol overhead.

The gross bit rate is related to, but should not be confused with, the symbol rate in baud, symbols/s or pulses/s. Gross bit rate can be used interchangeably with "baud" only when each modulation transition of a data transmission system carries exactly one bit of data; something not true for modern modem modulation systems and modern LANs.

Bitrate is commonly measured in bits per second (bps), kilobits per second (Kbps), or megabits per second (Mbps).