How does a Wi-Fi extender work? Let’s say if a certain location has a signal of -50dBm, how does adding an extender at that exact location boost the signal around it?
In: Technology
It’s a repeater. Every WiFi signal it receives, it broadcasts again. So, you put it at the end of your range, and your device transmits as “loud” as it can and it gets as far as your repeater, but the signal dissipates before it gets as far as the access point. That’s fine, because the repeater then transmits the signal again, and since it’s much closer to your access point, the original message reaches the destination. The reverse occurs when the access point transmits it’s response.
The problem with repeaters is that it generates more signal traffic. Understand that there is ONLY 1 electromagnetic spectrum. Every device using the 2.4 GHz band HAS TO TAKE TURNS, because if two devices transmit at the same time, it’s like two people talking at once – the receiver, WHICH IS EVERY DEVICE IN RADIO RANGE, all hear garbled noise and you can’t tell one signal from the other. The more devices in range, the slower everyone goes. It doesn’t matter if you divide things up by network, you’re still all using the same radio frequencies. If you’re close to your neighbors, then ALL your devices are picking up their noise, it’s just silently dropping the data because it’s not meant for them. WiFi, is a shared medium, it’s like if every device were wired, and sharing the same wire – you all have to take turns.
So a repeater is just one more participant, one more device vying to take it’s turn, meaning everyone has to wait that much longer to send their next packet. And more devices means more chance for collisions, meaning everyone has to wait even longer as data has to be resent.
The better thing to do is wire in all the devices you can. I recommend Cat-5e or Cat-6 STP with the proper grounded connectors. The thing is all conductors are antenna, so a long run of copper can pick up a lot of RF noise, so by shielding your runs, you’ll get far better performance. Anything you wire in means you free up the air waves, making your whole WiFi network, and that of all your neighbors, that much faster. It also cuts out the need for this repeater.
Barring that, the next best thing is to change your antenna to something with higher gain. This makes the most sense for stationary devices, like desktops or televisions, which may have an external antenna. A higher gain antenna simply means a directional antenna pointed directly at the access point. Instead of wasting electromagnetic energy sending your signals in all directions – all directions your access point ISN’T, you can direct all that energy to where your access point IS. This is a “passive” solution, in that it doesn’t require additional electronics or power. You’re not repeating your signal, you’re concentrating the energy and sending it in a focused beam. This solution isn’t practical for things like laptops or cellphones, especially since these devices almost universally don’t have external antenna. You can still prop the thing in front of an old DirectTV dish – which is the right size for WiFi, but that would be cumbersome.
Barring that, I would recommend moving your AP closer to where you use it most, and consider how to configure your home network more efficiently for your most common use cases.
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