## Bit Rate v/s Baud Rate

Tuesday, 3 April 2012

BIT RATE:  The bit rate is measured as number of bits transferred per second.
Unit symbol :
bit/s or bps

BAUD RATE:  The bit rate is measured as number of symbols or  pulses transferred per second It is also called as symbol rate.
Unit symbol : Bd/s

1 kBd = 1,000 Bd

Example: 1000 Bd is equivalent to a symbol rate of 1,000 symbols per second.
For a modem, this corresponds to 1,000 tones per second, and
For a line code, this corresponds to 1,000 pulses per second.
Hence. the symbol duration time can be calculated as follows: 1/1,000 second = 1 millisecond.

GROSS BIT RATE: The gross bit rate is measured as the total number of physically transferred bits per second(bps) over a communication link, including useful data as well as protocol overhead.
Unit symbol : Rb or fb

KEY POINTS:

1. In bit rate, 1000 bit/s or b/s should be represented as kbps and NOT Kbps
2. The formal abbreviation for "bits per second" is bit/s and NOT bits/s.
3. The symbol rate is related to but should not be confused with gross bit rate expressed in bit/s. Example: If N bits are conveyed per symbol, and the gross bit rate is R, inclusive of channel coding overhead, the baud rate (symbol rate) fs can be calculated as:

$f_s = {R \over N}.$

 BIT RATES Name Symbol Multiple Decimal prefixes kilobit per second kbit/s 103 megabit per second Mbit/s 106 gigabit per second Gbit/s 109 terabit per second Tbit/s 1012 Binary prefixes kibibit per second Kibit/s 210 mebibit per second Mibit/s 220 gibibit per second Gibit/s 230 tebibit per second Tibit/s 240

Reference: Internet and Wikipedia.