Science & Technology in Action

15th Edition

Maximising the use of the radio frequency spectrum

Commission for Communications Regulations

The radio spectrum is not unlimited. Different countries and regions around the world regulate which parts of the radio spectrum may be used in order to promote efficient use of the available RF spectrum, facilitate provision of services, encourage innovation and limit interference between services.

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The full lessons along with a supporting toolkit are available in three different formats, A4, A3 and as a Powerpoint deck.

Download Lesson Kit

Contains the full lesson along with a supporting toolkit, including teachers’ notes.

Lesson excerpt


Over the past few decades there have been remarkable developments in mobile communications technology. We have become accustomed to sending and receiving images and video on mobile devices but we are often unaware of how it works and of its limitations.

Mobile communications depend fundamentally on sending and receiving radio transmissions. Like X-rays, ultraviolet and visible light, radio waves are part of the electromagnetic spectrum (EMS). The energy of electromagnetic waves is proportional to their frequency and inversely proportional to their wavelength. Longer waves have lower energy and shorter waves have higher energy. The energy of radio waves and microwaves is much lower than that of visible light.

The radio spectrum is not unlimited. Different countries and regions around the world regulate which parts of the radio spectrum may be used and for what purpose. ComReg (The Commission for Communications Regulation), which is the regulatory authority in Ireland, is a member of the European Conference of Postal and Telecommunications Administrations (CEPT) which regulates telecommunications standards in Europe (including the EU). Regulation is needed in order to:

• promote efficient use of the available RF spectrum

• facilitate provision of services to consumers (radio, TV, mobile phone, broadband)

• encourage innovation

• limit interference between services.

ComReg can license or auction segments of the radio frequency (RF) spectrum to service providers for use in limited areas and for a specific number of years.

True or False?

  1. The electromagnetic spectrum means the colours of the rainbow. false
  2. Higher frequency waves have shorter wavelengths. true
  3. The energy of electromagnetic waves is proportional to their frequency. true
  4. All phone service providers use the same RF channels. false
  5. 2G phones used analogue voice signals. false
  6. Text messaging was introduced on 2G phones. true
  7. Each phone ‘generation’ improved data speeds. true
  8. A ‘byte’ is another name for a ‘binary digit’. false
  9. Lower frequency RF is usually better in rural areas. true
  10. Data speeds on 4G phones are about ten times faster than on 2G. true
  11. In Ireland 4G phones operate on the 900 MHz, 1800 MHz bands. false

Glossary of terms

an electrical signal whose amplitude or frequency is a function of the variable being represented; e.g. the voltage produced by a microphone is proportional to the variation in the pressure of the sound wave it detects
a range of radio frequencies used for a particular purpose
the numerical difference between the upper and lower frequencies of a signal
a binary digit, usually represented by 1 or 0
binary digit
either of the digits 0 or 1, as used in the binary number system.
eight bits; the byte is the unit of computer data
relating to cells
subsections of a radio frequency band
Cordless phone with digital features (DECT: Digital Enhanced Cordless Telecommunications)
converted in form that has discrete levels
electromagnetic spectrum
the entire range of electromagnetic radiation. The spectrum usually is divided into seven sections. From the longest wavelengths to the shortest, these are radio, microwave, infrared, visible, ultraviolet, x-ray, and gamma ray radiation
the electromagnetic spectrum
European Union
the number of complete oscillations or cycles per second
Global System for Mobile Communications; a European mobile communications standard which uses SIM cards
high frequency radio communications (also known as 'short wave radio')
kilohertz (one thousand oscillations per second)
Long Term Evolution; telecommunications protocols that are used in 4G phones; based on GSM but with many additions and enhancements
a computer networking device that directs data packets across a network to their destination
a million bits
megahertz; 1 MHz = 1, 000, 000 per second
Systems of interconnected components.
radio frequencies (RF) in the range of 300 kilohertz (kHz) to 3 megahertz; formerly widely used for radio broadcasts before the advent of FM radio
the company or organisation providing the (mobile phone) infrastructure or service
radio frequency; the range of electromagnetic waves used for radio communication; generally in the range 20 kHz to 3 MHz
radio local area network
a telecommunications infrastructure designed for rural areas
service providers
the company or organisation providing the (mobile phone) infrastructure or service
super high frequency radio signals; 3 GHz and 30 GHz; also known as 'centimetre band' or 'centimetre wave'
Short Message Service (SMS) is a mobile communication service enabling users to exchange short text messages
refers to media received as a live 'stream' rather then being downloaded first
ultra high frequency; radio frequencies ranging from 300 MHz to 3 GHz
electromagnetic waves beyond the violet part of the spectrum and therefore invisible; ranging from 10 nm to 400 nm
voice signals
audio signals in the range 300 Hz to 3400 Hz that are transmitted as a varying voltage or are used to modulate a radio frequency 'carrier'
in a wave motion, the distance between two successive crests (in a transverse wave) or compressions (in a longitudinal wave)
relatively high energy electromagnetic radiation with wavelengths in the range 0.01 nm to 10 nm; x-rays are highly ionising