5G and Radio Waves
All cellular mobile networks operate via radio waves, using frequency bands within the radio spectrum.
The radio spectrum covers frequencies from a few hundred kilohertz (kHz) right up to almost 100 Gigahertz (GHz). The Government allocates different spectrum bands to a wide variety of uses – everything from AM and FM radio, television (terrestrial and satellite), WiFi and of course mobile communications.
Hertz measures the frequency of a radio wave, in the number of cycles per second. 1 kilohertz (kHz) is 1000 cycles per second, 1 megahertz (MHz) is 1 million cycles per second, 1 gigahertz (GHz) is 1 billion (1000 million) cycles per second.
All radio waves fit within what is called the “electromagnetic spectrum”. The radio waves used by mobile technology, including 5G, are called “non-ionising” which mean they don’t carry enough energy to damage human DNA.
Frequently asked questions
What radio spectrum will 5G use?
- Although 5G will work via existing frequency bands between 0.5GHz and 4GHz already reserved for cellular mobile communications, the Government is allocating additional frequency bands to ensure there is sufficient capacity alongside earlier generation services.
- The initial allocation involves the 3.5GHz spectrum band, which is broadly similar to frequencies used already to deliver 2G, 3G and 4G services.
Won’t 5G also be using new, higher frequencies?
- Further into the future, 5G is also designed to operate on higher frequency bands above 10 GHz (otherwise known as “millimetre wave” bands). Although cellular mobile networks in New Zealand don’t yet use these higher frequencies, other services do – such as satellite TV transmissions.
- Once relevant spectrum is allocated, New Zealand mobile operators will look to deploy mm wave frequencies for 5G in future years.
- The nature of these frequencies means they only operate effectively for cellular mobile services across relatively short ranges (up to a few hundred metres), meaning their use will mostly be suitable only within certain densely populated urban areas (e.g. CBDs, sports stadiums, etc.)
Note: The higher the frequency of radio wave transmissions, the shorter the length of each wave. At frequencies above 10GHz, the waves are millimetres in length or smaller.
Why do radio waves create electromagnetic fields (EMFs) and what are the risks from them?
- All radio waves fit within what is called the “electromagnetic spectrum” – this spans a wide range of wave types such as light (visible light from the sun as well as infrared and ultraviolet light) right up to X-rays and gamma rays.
- All such waves create electromagnetic fields (EMFs) which vary greatly in terms of size and intensity.
- The radio waves used by cellular mobile technology, including 5G, are called “non-ionising”’ which mean they don’t carry enough energy to damage human DNA.
- In contrast, “ionising” EMFs carry much greater risk (which is why, for instance, special care and protection is needed when patients have X-rays).
- Scientists have been studying the effects of electromagnetic fields (EMFs) on people and the environment for decades. You can find out more at the World Health Organisation website or on the Ministry of Health website.