What is Spectrum in Telecom and different types of Spectrum.
                     WHAT IS SPECTRUM IN TELECOM AND 
DIFFERENT TYPES OF SPECTRUM?
What is Spectrum?
• Spectrum refers to the invisible radio frequencies that wireless signals travel over. Those 
signals are what enable us to make calls from our mobile devices, tag our friends on 
Instagram, call an Uber, pull up directions to a destination, and do everything on our mobile 
devices.
Source: www.ctia.org
Electromagnetic spectrum
• The frequencies we use for wireless are only a portion of what is called the electromagnetic 
spectrum.
• The entire electromagnetic spectrum encompasses other frequencies we interact with daily, 
even if we don’t think about them.
Source: www.ctia.org
Wavelengths
• Portions of electromagnetic spectrum are grouped in “bands” depending on their 
wavelengths—the distance over which the wave’s shape repeats.
Source: www.ctia.org
Range of Electromagnetic Spectrum
• The full electromagnetic spectrum ranges from three Hz (extremely low frequency) to 300 
EHz (gamma rays).  The portion used for wireless communication sits within that space and 
ranges from about 20 KHz to 300 GHz.
Source: www.ctia.org
Categories of Spectrum
• Because a range of spectrum frequencies can be used for cellular communications, different 
bands have slightly different characteristics. 
• For the purposes of wireless communication, we can think of spectrum in three categories: 
low, mid, and high-band spectrum.
Source: www.ctia.org
Low-band spectrum
• Low-band spectrum travels longer distances with minimal signal interruption. Today’s 
wireless networks are built primarily on low-band spectrum, and the wireless industry has 
used this spectrum to build high-speed wireless networks.
Source: www.ctia.org
High-band spectrum
• High-band spectrum (above 24 GHz) travels much shorter distances—think meters, not 
miles—compared to low-band spectrum, but offers high capacity and ultra-fast speeds.
Source: www.ctia.org
Mid-band spectrum
• Mid-band spectrum (between 3 and 24 GHz) blends the characteristics of both low- and 
high-band spectrum—providing a mix of coverage and capacity.
Source: www.ctia.org
How Does Spectrum Work?
• These spectrum frequencies are transmitted between cell sites and our mobile devices. The 
most common cell sites in use today are the 150-foot cell towers we are accustomed to 
seeing along highways or atop tall buildings. 
Source: www.ctia.org
The Future
• Spectrum is a highly complex concept, but the bottom line is that it’s the core component of 
wireless communications. 
• All the amazing benefits 5G promises smart cities, telemedicine, agricultural advancements, 
and more depend on it. And the more effectively we utilize it, the greater the benefits.
Source: www.ctia.org