Wall outlet Hz v broadband Ghz interference ?

My broadband provider tells me that I should not place anything between my broadband router and the power outlet as it could interfere with the workings of their internet router. This hocus-pocus attitude was also taken with a fellow renter in the same building as myself, where I used a remote plug to reset the router periodically as it was always struggling and in a too high a place to easily reach.

My view was that her computer didn't have a 5Ghz arial and so had to use the crowded 2.4Ghz band, and her laptop was old, and she was an idiot too. However, my ISP says that they cannot test my line because of interference, but will it harm the router's performance ?

My understanding is that the frequency of the mains outlet is about 50Hz, while the router is working in the GHz band, so it shouldn't matter ?

Who is right, and what do I have to fear using a remote plug with my internet router ?

As far as I know, the power supply will have little to no effect on the wireless signal. While the plug goes to AC power, usually the plug includes a transformer/rectifier that will provide a 12-24V DC power supply to the router.

I don't have much experiences in electronics and wireless signals but there are many other sources that can cause interference with the 2.4GHz band such as other nearby routers (assuming you are in an apartment building), microwaves, cell phones, bluetooth devices.

borren said:

My broadband provider tells me that I should not place anything between my broadband router and the power outlet as it could interfere with the workings of their internet router.

Click to expand...

Technically, they're correct. 

Like you mentioned, you have the remote switch between your router's power supply and the wall outlet for remote restarting. This may not directly affect the internet connectivity, but it does add another point of failure. This means that if you are troubleshooting issues with your ISP, this is just another device that they have no familiarity with and could prolong troubleshooting.

For instance, if you were to call about internet not working, your ISP will more than likely have you restart your router. In this hypothetical scenario, the remote switch may be faulty and preventing the router from powering on. So now the ISP's time has been wasted troubleshooting an issue that has nothing to do with their area of responsibility.

Getting even more specific, the remote switch could indeed cause unwanted interfere on your internet. The remote switch more than likely has an internal switching power supply providing power for the internal ICs. These switching power supplies can run up to 2MHz, and could easily generate harmonics in the GHz range. These high frequency signals could be coupled into the AC signal going to your routers power supply, and then couple onto the DC line powering the internal ICs of your router.

Though proper design of the remote switch and router power supply would limit the signal noise, there are many, many cheap devices out there that do not take low noise design into consideration. It is not out of line for your ISP to say anything between your router and AC line could cause interference.

An I haven't even touched on the issues that could be caused by EMI. Your remote switch, or literally any other electronic device, could generate interference that could wirelessly interfere with the internal workings of your router. It doesn't even have to be within the GHz range of wifi, since there are probably communication lines in the router that operate at much lower frequencies. For instance, I2C and SPI data communication (inside the router) could be affected by EMI or noisy power supply rails.

Thanks for the solid info.

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