Spectrum

Spectrum

Subject: Science and technology

Context: the Centre garnered ₹77,814.80 crore in revenues in spectrum auction. It exceeded the expectation as Telcos focused on renewing expiring spectrum and consolidating holdings in select bands.

Concept:

• It is the invisible radio frequencies (used for communication) that wireless signals travel over.
• The frequencies we use for wireless are only a portion of what is called the electromagnetic spectrum (encompasses other frequencies we interact with daily).
• VIGBYOR represents colors that make up the visible part of spectrum. Other parts of spectrum carry broadcast radio and television or serve other everyday functions.
• Spectrum wavelengths are classified into different bands within the electromagnetic spectrum range:

• The entire electronic 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.

How does spectrum work?

• Different bands have slightly different characteristics. Generally in case of communication the spectrum is divided in three categories: low, mid, and high-band spectrum.

1. Low-band spectrum (under 3 GHz):Travels longer distances with minimal signal interruption. Most wireless networks are built primarily on low-band spectrum, and the wireless industry has used this spectrum to build high-speed wireless networks
2. High-band spectrum (above 24 GHz) travels much shorter distances (e., in meters), but offers high capacity and ultra-fast speeds.
3. 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.

• These frequencies are transmitted between cell sites (cell towers) and our mobile devices.
• Spectrum is a finite resource and hence its efficient management through auction is needed. The Union government through DoT owns all the publicly available assets within the geographical boundaries of the country, which also include airwaves.