kbps or kilobits-per-second is a measure of data throughput.
Hz is a measure of Frequency Bandwidth.
The tool answers the question: How much bandwidth (in Hz) is required to transfer a user-specified number of kilobits every second in a communication system?
Enter:
- Data rate in kbps
- Signal-to-Noise ratio (default value is 10 dB)
Example Calculations
For a communication channel with 10 dB SNR, it takes 2900 Hz or 2.9 kHz of Bandwidth to transfer 1 kbps.
As the SNR is increased to 20 dB for instance, it takes about half the bandwidth – 1500 Hz or 1.5 kHz.
As the signal to noise ratio is increased, it improves the reliability of the communication medium. Hence a smaller amount of bandwidth (Hz) is required to transmit the same amount of data (measured in kbps).
Formula
To calculate the bandwidth we use the Shannon-Hartley formula
B = C/(Log2(1 + S/N))
where,
- B is the bandwidth in Hz
- C is the throughput in bits per second
- S/N is the Signal-to-Noise ratio
Key Assumptions
The Shannon-Hartley formula makes the following assumptions:
- The noise is white Gaussian. In other words it does not consider the effect of Fading which can cause additional signal losses.
- The throughput in bit-per-second is an upper bound. It represents an ideal condition that can be achieved with an arbitrarily low error rate.