How does Powerline Networking works?

[Vindola]

Can someone explain to me HOW does powerline networking works?

 

I searched it up, most of what I found is what it does, not how it does it.

 

Yes, I know it uses the house's AC circuit as a network, but how does it do that? What sort of technology is behind these things that make it capable of sending data using an electrical circuit? 

 

 

 

 

Thanks for any good information folks.

[Vitalius]

How does WiFi work? An antenna sends out electromagnetic waves at a certain frequency which another antenna receives and interprets as 1's and 0's. 

The same thing essentially happens with a powerline network. Except the waves are through the electricity/copper wires in your house. Powerline adapters on the same frequency are connected and through a security encryption system prevent other adapters from connecting (unless they have the password).

It's the same concept as WiFi, but instead of through the air like radio waves, it's through the electricity in your house.

This is why they won't connect through certain electrical boxes/barriers. The power is effectively "cleaned" meaning all modulation (i.e. messing with the wavelengths) is removed from the electricity and no signal gets through.

A surge protector is an example of what does this, and why powerline adapters don't work through them.

If you are wondering how a signal is actually transferred from one adapter to the other over the electrical line, electricity can only flow in a circuit. That means that when electricity goes into a device, it must come out of it as well (though at diminished voltages and/or amperes). 

The electricity flows through the powerline adapter and the adapter modifies the wavelengths that the electricity flows at (I'm not sure what is actually modified, volts, amps, or something else) and that's what the other adapters see. These tiny changes.

Because the modulation (changing of the wavelengths) is so minimal, however, it doesn't mess with your electricity. Meaning your microwave won't stop working because the electricity changed.

Quote from the future:
 

@Vitalius You said frequency changes... you should've written that the secondary frequency does, not primary(50/60 Hz) and the secondary is superposed on top of the primary, but with relatively small amplitude.

[Elven]

Hey @Vindola

 

Essentially, and all you need to know is. A connection between 2 devices is made by using the infrastructure of the current electrical wiring of the building. You need a pair of powerline plugs to achieve this.

 

For example, you have your router in one room. Which an ethernet cable from the router is connected to one of the powerline plugs that goes into a plug socket. You then have the other powerline plug in the other room of the house which is connected to a desktop computer, using an ethernet cable from that powerline adapter to the desktop (in the same way as the router to the first powerline adapter was set up)

 

Once the powerline adapters have communicated to each other (upon connecting to the plug socket, somtimes involves pressing a little button on both adapters). they establish a connection and create a network link between the two.

 

One thing to note, is the same basic rules of ethernet standards apply. e.g. the connection between both adapters can't be longer than 100 metres, otherwise the signal will be too weak and no connection can be made.

 

I hope this helps 

 

Elven

[Vitalius]

Also note that if you plan to have multiple adapters connected to each other, as in, more than 2, you probably want the one connected to the router to have a gigabit ethernet port on it. 

So, say you have 4 adapters. 3 for different devices (consoles, desktops, laptops, wtv) and the 4th for the router. The 4th would need a gigabit (10/100/1000) ethernet port to be able to allow all 3 of the other devices to access the router (and the internet) without a bottleneck. 

Say I have a media streaming and backup server. And all 3 devices are accessing it at once. And the connection between the server and the router is a direct ethernet one, and the 3 devices are connected through the powerline network. 

If 2 of those devices are streaming 1080p video, and the 3rd one is doing a system backup, it's going to bottleneck a 10/100 ethernet port. So the gigabit port here becomes very important. 

That's an extreme case, but still. It's very possible to bottleneck a 10/100 port when multiple devices are being pushed through it. And most Powerline Adapters have 10/100 ports. 

[juretrn]

@Vitalius You said frequency changes... you should've written that the secondary frequency does, not primary(50/60 Hz) and the secondary is superposed on top of the primary, but with relatively small amplitude.

[Vitalius]

@Vitalius You said frequency changes... you should've written that the secondary frequency does, not primary(50/60 Hz) and the secondary is superposed on top of the primary, but with relatively small amplitude.

That makes a lot more sense. I didn't understand what was changing, which is why I just said it semi-ambiguously. 

[Vindola]

@Vitalius You said frequency changes... you should've written that the secondary frequency does, not primary(50/60 Hz) and the secondary is superposed on top of the primary, but with relatively small amplitude.

 

Care to explain the difference between the two? (Or at least direct me to a place that explains it well) I know that AC electric current is usually sent at 50 to 60Hz depending on what country you live at, but how does a secondary frequency (which I suppose is the frequency that powerline adapter communicates through) correlates to the primary frequency? 

[juretrn]

Care to explain the difference between the two? (Or at least direct me to a place that explains it well) I know that AC electric current is usually sent at 50 to 60Hz depending on what country you live at, but how does a secondary frequency (which I suppose is the frequency that powerline adapter communicates through) correlates to the primary frequency? 

Sorry for my late reply. 

The two "frequencies" are not really correlated - they are two completely separate signals, added one on top of the other. The comm signal is not really a single frequency, but a whole band of frequencies, meant for data transfer.  Basically, the communication signal is added to the 220 / 110 V base, as the comm. signal is in the range of a few milivolts and several MHz. What basically happens is the signal from your computer is converted from a form, suited for Ethernet cable to a form, more suited for powerline. That signal is then added to the mains voltage. If you were to graph that, it would look like your house voltage went from a smooth sine wave to a slightly jagged one. On the receiving end, the 50 Hz / 60 Hz component would be removed, most likely by a band-pass filter (a circuit that only lets through a certain band of frequencies) and some digital signal processing.  

 

The image illustrates what I'm talking about.