The next evolution of cellphone network technology is here, but many advocacy groups and businesses are saying now is not the time to go there.

Technology blogger and teacher Kevin Andrews explains that 4G and 5G networks bring the speeds that people enjoy today, and Millimeter Wave is essentially the next evolution of that.

He says smartphones use specific frequencies, but as more people come online those frequencies are starting to get crowded.

Millimeter Wave would open up a new spectrum that hasn’t been used before, however, he says that is raising concerns about the health and environmental impacts of using such an untested technology.

According to Andrews, telecommunications companies say the signal would be weak, only cover short distances, and would require expensive equipment upgrades.

On the advocacy side, he cites arguments from the group Canadians For Safe Technology.

That group, he says, claims that not enough has been done to prove the long-term health effects of that technology and that there’s “strong scientific evidence” to suggest that radiation from 5G wireless technologies can cause serious adverse effects.