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wifi cost me like 30USD while mobile internet 10USD, I thought to save this monthly bill by purchasing a mobile-phone-router. The only thing that blocks me from that is radiation. I'm far fetched from physics but I read over the net this: (maybe I'm wrong)

  1. Typical mobile phone radiation 1W/m^2
  2. Typical wifi radiation 100mw/m^2

My mobile phone router is going to be farther away from my wifi router by around 4 meters.

So my calculation is this:

  1. Distance from mobile router ~10m => 1W/m^2 so 10 square root, it's going to be 2mw/m^2

  2. Distance from wifi router is ~5m => 100mw/m^2 so 5 square root of it is going to be 2.5mw/m^2.

Question: Is it then correct to say that if my phone router distance is 10 meters while my wifi router distance is around 5 meters the radiation I'm exposed to is around the same? (I understand their frequencies is rather the same so ignoring that).

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It would be correct if your input data were correct and correctly interpreted.

Your calculations are based on the assumption that a typical mobile phone has 1W/m^2 radiation at a distance of 1m from the phone and, similarly, that a typical wifi router has 100mW/m^2 radiation at a distance of 1m from the router.

This interpretation does not seem to be correct. For instance, a typical phone should have a total radiation power much less than 100mW (20dBm). If the phone was radiating this power uniformly in all directions (isotropic radiator), at a distance of 1m, the radiation power density would be 100mW/12.57m^2(area of a 1m radius sphere)=8mW/m^2.

In reality, the radiation is stronger in some directions and weaker in other directions, but, for a phone wifi antenna, the radiation gain in the strongest direction is not likely to be more than, say, 2x, i.e., the maximum power density at 1m distance should be less that 8mW*2=16mW/m^2, which is more than two orders of magnitude less than what you've assumed.

The interpretation of the wifi router power is a suspect as well, for similar reasons.

In general, the power of a router should be higher than the wifi power of a phone, but, still, 5m seems like a safe distance.

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