Ask HN: Is cell phone radiation still a concern in 2023? • Hacker News Board

Re: Ask HN: Is cell phone radiation still a concern in 2023?

#11

Post by 2rsf » Fri, Sep 15, 2023, 10:58 AM UTC

mikewarot wrote: post #10

Here's a fringe opinion you likely haven't heard before. I think that small quantities of continuous RF really aren't a problem.[1] I think it's the rapid edges of packets that are the problem. The envelope of a modern TDMA/CDMA signal, as a series of packets, creates a little heating, then none, then a little heating... this is true for bluetooth, cell phones, WiFi, etc. Sometimes you'll hear the packets in your spe…

TDMA is long gone, and there are no "edges of packets" as you imagine them. I am not an expert, I only have little experience and knowledge from working in the area, but for example a few symbols are transmitted together using carriers at different phases. Those audio noises used to exist in the GSM area but no longer in 3G and 4G.

Re: Ask HN: Is cell phone radiation still a concern in 2023?

#12

Post by mikewarot » Fri, Sep 15, 2023, 11:23 AM UTC

2rsf wrote: post #11

mikewarot wrote: post #10

Here's a fringe opinion you likely haven't heard before. I think that small quantities of continuous RF really aren't a problem.[1] I think it's the rapid edges of packets that are the problem. The envelope of a modern TDMA/CDMA signal, as a series of packets, creates a little heating, then none, then a little heating... this is true for bluetooth, cell phones, WiFi, etc. Sometimes you'll hear the packets in your spe…

TDMA is long gone, and there are no "edges of packets" as you imagine them. I am not an expert, I only have little experience and knowledge from working in the area, but for example a few symbols are transmitted together using carriers at different phases. Those audio noises used to exist in the GSM area but no longer in 3G and 4G.

It took a lot of Wikipedia reading, but I finally got to OFDMA[1], which apparently is used by my 4G phone to talk to the world. I had no idea it just kept spewing RF at all times. Though, it will be transmitting more or less signal depending on how many subchannels it is using.

There will be experiments with an RF sniffer later when I get to my friends repair shop.

[1] https://en.wikipedia.org/wiki/Orthogonal_frequency-division_...

Re: Ask HN: Is cell phone radiation still a concern in 2023?

#13

Post by 2rsf » Fri, Sep 15, 2023, 12:11 PM UTC

mikewarot wrote: post #12

2rsf wrote: post #11

Earlier quoted context omitted.

TDMA is long gone, and there are no "edges of packets" as you imagine them. I am not an expert, I only have little experience and knowledge from working in the area, but for example a few symbols are transmitted together using carriers at different phases. Those audio noises used to exist in the GSM area but no longer in 3G and 4G.

It took a lot of Wikipedia reading, but I finally got to OFDMA[1], which apparently is used by my 4G phone to talk to the world. I had no idea it just kept spewing RF at all times. Though, it will be transmitting more or less signal depending on how many subchannels it is using. There will be experiments with an RF sniffer later when I get to my friends repair shop. [1] https://en.wikipedia.org/wiki/Orthogonal_freque…

It also has simple power control, making sure that all phones are received at the same power on the receiving antenna. Overall OFDMA is magic, if you can put your hands on a spectrum analyzer with constellation diagram you will be amazed.

Re: Ask HN: Is cell phone radiation still a concern in 2023?

#14

Post by mattbrewsbytes » Fri, Sep 15, 2023, 1:10 PM UTC

RetroTechie wrote: post #5

People have been afraid to have cell towers placed nearby (like on roof of multi-story housing they live in). But what's funny & non-intuitive: Whatever that cell tower puts out in radiation, only a small fraction reaches you (distance from antenna & power level decreases with square of that distance). But your phone otoh, many people hold it right next to their head. So it likely puts more radio power into your head…

> Personally I think phone health effects exist, but more likely due to psychological effects of doomscrolling, social media use, etc. And effects on sleep of too-bright screens / phone use right before bed time.

I'd agree, there are far more studies floating around that claim measurable impacts on peoples mental health from social media which is typically delivered via smart phone.

I would venture a guess that a sunburn, essentially a radiation burn, and has more health impacts than cell tower radiation.