Explained: How 5G requires more cell sites, what this means for New Zealand

5G is promising a new world of connectivity.

In a Newshub Because it Matters story on Sunday night, we showed how it would work and the arguments about whether wireless technology is safe.

But in the future, 5G will be using different radio frequencies that require many more cell sites.

Current 5G is so fast that while Team New Zealand tests its boats on the water, the data flows real-time to the onshore team.

But that part of the radio spectrum is crowded, so 5G will eventually migrate to higher frequency radio waves, called millimetre waves - but opponents claim they're untested.

Vodafone's head of technology was quick to confirm that millimetre waves aren't new technology.

"These waves have been around for a long period of time, in fact infinity, but we are harnessing them," Tony Baird told Newshub.

4G technology uses radio waves that can travel long distances, but can't carry a lot of data.

But 5G can use millimetre waves that carry much more data - but only travel short distances.

Millimetre waves also can't penetrate buildings, which means there may be more mini 5G cell sites in built-up areas that are about the size of a wireless router.

Baird added that these would be built "every few hundred metres" on houses and light poles, but that'll happen in more than five years from now.

Millimetre waves are already used in airport full-body scanners, microwave signals and in some television transmissions.

But the waves' potential use has prompted the global Stop 5G movement to claim humans are being used as lab rats.

"What is wrong with that is that the health effects of those frequencies have not been adequately tested for safety," movement member Michael Baughan told Newshub.

Stop 5G points to US Senator Richard Blumenthal, who last year asked members from the American wireless industry whether they were aware of independent research.

They said they weren't aware, prompting Blumenthal to say companies are "really flying blind here".

"Common sense dictates it should be stopped until the appropriate safety research has been done," Baughan said.

But the Prime Minister's Chief Science Adviser said the current safety standards already apply. 

As long as radiation from millimetre wave cell sites stays below these safe levels, it's okay.

"People might not like the look of them, might not want to be next to them, but overall the exposure isn't necessarily going up - you just have more lower power towers instead of fewer more powerful ones," Professor Juliet Gerrard told Newshub.

Not everyone wants to surf the 5G wave - but from driverless cars, flying taxis, smart nappies and smart toothbrushes, the rush to 5G is on.