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I have a ton of neighbors surrounding my area into my wifi zone I believe it's causing quite some problems for my mother's tablet which is relatively new and the amazon TV fire stick even though these devices say they have full bar as usual.

There are 3 registered networks besides mine using the exact same channels on 2.4ghz range(I would like to be able to focus on this frequency range). I don't think I should switch to other channels due to the other channels being overcrowded as well like mine is; It seems like every time I try to change a channel their wifi switches into the channel I purposefully changed it, this happens over night and very often it does this.

I've been using wifi analyzer app on my cell phone, it shows each individual wifi points with signal strength. Typically on channel 6 the signal strength isn't anywhere stronger than my wifi router in range with all the devices. In some spots in my house there'll be ~20 dBm before it equals up to my wifi strength.

Is it possible I can use my desktop computer with cat cable tethered to it too scan the channels with inSSIDer? Or would I need to get a wifi adapter to scan the network for inSSIDer?

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    They have wall coating/films that block wifi signals if you put some up in the direction of other routers it will block them. Unfortunately, it also blocks cell reception, but used on a small section of outside wall it shouldn't interfere too much. – cybernard Mar 19 '16 at 4:39
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    That's a good point of RF shielding, could be also be possible to have a cellphone signal extender I percieve as a solution. – Cryptixer Mar 20 '16 at 4:09
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    Why do you not want to try 5GHz? You'll probably have to make the switch sooner or later anyway. – Moshe Katz Mar 21 '16 at 19:53
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    I don't believe the current devices could handle the 5ghz and mother doesn't want to upgrade the device, perhaps higher frequency makes signal more weaker in distance comparing to 2.4ghz. – Cryptixer Mar 21 '16 at 23:56
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    IMPE the vast majority of tablets are new enough (being tablets) that 5 GHz is built-in - I would certainly test for that before assuming it's not, unless you have full specs on the device and know it's not. – Ecnerwal Apr 28 '16 at 18:02
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Speaking as a wireless network admin, the short course on 2.4:

  • In most of the world, there are only 3 2.4 GHz channels you should ever use: 1, 6, 11
  • All the rest of them overlap - the idea that adjacent channels should not interfere with each other is broken in the 2.4 spectrum - accept it and move on. There are only 3, and they are called 1, 6 and 11.
  • Unless you are in the boonies (WiFi analyzer shows nothing if you turn off your own wireless) 2.4 should only be run at 20 MHz channel width, never at 40 MHz. At 40 MHz, there are no non-overlapping channels, since it takes two, and there are only 3 to start with, so as soon as you have 2 APs trying to run 40 MHz, you have interference.
  • Everything that can be wired should be wired. Access points should be as close as possible to the end use devices, and should generally be turned down somewhat from default (almost always maximum) power levels; end use devices generally cannot talk back to the AP at high power level, so a lower power from the AP balances the communication better.

In any high-density environment, 5GHz offers great benefit, precisely because it's terrible at penetrating walls, making your neighbor's AP less of an issue for you - also, in most parts of the world, there are MANY more channels available in the 5 GHz band. However, the terrible at penetrating walls part applies in your house as well, so you may need to wire more access points for good 5 GHz wireless coverage.

And before you go there: wireless repeating is terrible for wifi performance. Good wifi is built on wires and fibers.

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All the Wi-Fi equipment that I have seen does not have the option to disable carrier sense, or otherwise disable the feature to avoid causing interference to other nodes by waiting to transmit while the channel is busy. This of course slows down your speed by being polite to others. So what happens is people set their network to use an in between channel that overlaps other networks' channels but isn't being used by any other network. Since their Wi-Fi nodes can no longer see frames sent by the other networks' nodes because the channels aren't exactly the same, their network works at full speed, but only at very short range. This effectively disables carrier sense. The result of this is that everything works only at very close range and becomes very unreliable if people move away from their access points. Now there is no channel to use that is free from networks partially overlapping the channel that you're on even if you just want a slow but reliable connection that works 100 feet away.

Other than moving to 5GHz, maybe the best solution to this issue is to try to put together a band plan for your neighbors to abide by. You could hand something out recommending everyone to stick to using channel 1 or possibly 11 if they prefer reliability and maximum range, or use channels 5, 6, and 7 if they prefer to get high speeds but only at close range. Double wide 40MHz 11n networks should operate on channels 5, 6, or 7 with the secondary channel above, or be disabled entirely since it's often slower in a congested area like this. This is about the best you can do to satisfy both use cases.

As far as your question about scanning the area with your desktop, yes you would have to get a plug in Wi-Fi adapter to be able to use inSSIDer. But even with that utility, it's unlikely that you'll be able to find a channel to switch to.

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There are multiple things that can happen here:

Hidden Node Problem: https://en.wikipedia.org/wiki/Hidden_node_problem

IEEE 802.11n 40 MHz channel switching to 20 MHz: Newer WiFi APs support 40 MHz channels and use them. Which is no problem as long as no data flows. When data flows and other nodes also use the same channels the AP might decide to switch back to 20 MHz. But then it might look like the adjacent channels are not used and it switches back to 40 MHz. This can happen so often, that your throughput collapses. The combination with hidden node problem makes this scenario worse. Try if you can limit your AP to only use 20 MHz channels.

Amazon Fire Stick and many small devices (like smartphones and tablets) have really small antenna and are therefore a good deal worse at sending and receiving wifi signals. Also the orientation of the devices can influence signal quality. An isolation of the antennas is also much easier achieved by body parts (hands holding the device) or other cables (which are connected to the same TV as the Fire Stick).

Also, wifi channels do overlap. The overlap is bigger for 802.11b than for 802.11g/n. Have a look at https://en.wikipedia.org/wiki/List_of_WLAN_channels So, if you use channel 6 and some of your neighbors use channels 3,4,5,7,8, or 9 you will have interference. So try to find a channel where you do not have this kind of partial overlap.

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