Difference Between Bandwidth and Spectrum

The key difference between Bandwidth and Spectrum is that the bandwidth is the maximum rate of data transfer within a certain period of time whereas a spectrum is a collection of waves with particular frequencies arranged in order.

Bandwidth and spectrum are two common terms in the fields of Electrical Engineering, Telecommunication, and networking.

CONTENTS

1. Overview and Key Difference
2. What is Bandwidth
3. What is Spectrum
4. Side by Side Comparison – Bandwidth vs Spectrum in Tabular Form
5. Summary

What is Bandwidth?

Bandwidth refers to the maximum amount of data that a medium can transmit in a unit time. It is possible to send more data if the bandwidth is high. And another method to explain bandwidth is as a range of signal between the higher (maximum) and lower (minimum) frequency that a signal can contain.

Frequency (f) is the number of oscillations that occur in a signal per second. Frequency measurement is Hertz (Hz). The period is the time to complete an oscillation (T= 1/f). When the maximum frequency is f(max) and the minimum frequency is f(min), the formula to calculate the bandwidth is as follows. Here, B denotes bandwidth.

 B = [f(max) – f(min)] bits/sec

What is Spectrum?

One common spectrum is the Electromagnetic Spectrum. It consists of all the Electro-Magnetic (EM) waves. Therefore, the vibration between an electric field and a magnetic field can create an electromagnetic wave or EM wave. Furthermore, the Electromagnetic spectrum is the collection of all electromagnetic waves after arranging them according to the wavelength or frequency.

The electromagnetic spectrum consists of many waves like radio waves, microwaves, infrared rays, visible light, Ultra Violet rays, X rays, Gamma rays, etc.  The radio wave has a higher wavelength and lower frequency. TV and FM radio use radio waves. The gamma-ray has the lower wavelength and higher frequency. Satellite communication use microwaves. Equipment such as remote controllers uses infrared radiation. Ultra Violet rays help to destroy bacteria and viruses etc. X rays help to detect broken bones and Gamma rays help to treat cancers.

What is the Difference Between Bandwidth and Spectrum?

Bandwidth vs Spectrum
Bandwidth is the maximum rate of data transfer within a certain period of time.	A spectrum is a collection of waves with particular frequencies arranged in order.
Usage
Helps to measure the amount of data that a medium can transmit per unit time.	In electromagnetism, it helps to identify the wavelengths and frequencies of electromagnetic waves.
Unit
bits/sec	There is no unit

Summary – Bandwidth vs Spectrum

Bandwidth and Spectrum are common terms in disciplines such as Telecommunication, Networking etc. The difference between Bandwidth and Spectrum is that Bandwidth is the maximum rate of data transfer within a certain period of time while a spectrum is a collection of waves with particular frequencies arranged in order.

Reference:

1.“Uses of Electromagnetic Waves.” Uses of Electromagnetic Waves | Revision World. Avaialable here

Image Courtesy:

1.’EM Spectrum Properties edit’By Inductiveload, NASA – Own work (CC BY-SA 3.0) via Commons Wikimedia