High Link Score, but poor connection quality.

[nbackus08]

Yes but its not always an easy task. If your neighbor is broadcasting these wireless networks you could ask them to turn the power down on their AP as its potentially smothering your wireless network with interference. In turn but Not recommended is to increase the power on your AP if possible. This is a bullying method but could provide better coverage to your devices. This likely wont fix the issue either. When the issue occurs how many devices are connected at one time? Are they all newer devices that support Wireless-N? If your AP is capable of disabling Mixed mode which supports B or G devices this in turn only allows Wireless N devices to connect which allows them to all speak the same language essentially. Having B or G devices mixed in causes the network throughput to slows to B or G speeds and your wireless N devices to wait on them to finish talking to the AP. Moderator ua549 mentioned in another post wifi-extender cuts bandwidth in half when used. This should be taken into consideration as well. What is the Make and Model of your AP? Based on your mac address it appears to be a Actiontec & AmpedWireless? I may be able to suggest what settings/parameters it supports to help stabilize and increase performance of your wireless network.

[Emerald Acid]

It's an older Verizon router from back when we had Fios at our old house. Model name of "MI424WR-GEN3I".

I've got no idea about the BGN support. Some of the stuff is more recent, like my desktop machine and my sister's laptop. Others are many years old, like the Kindles, and my, my stepfather's, and my mother's laptop. My laptop in particular is over seven years old.

I pretty much figured that using the signal booster cut down overall performance, but it's the only way to get internet signal to the entire house since the router can't be put inside properly due to... family disagreements.

As for how many connections at one time, I'm not sure the actual number, but I do know that there have been times where everyone was on their own computer and/or kindle at the same time, and our phones are connected to the network 24/7, and yet the signal was fine. And other times, I could be the only one actively using the network (desktop, and the always-connected phones) and the signal was absolute garbage.

[nbackus08]

After googling your model of Modem/Router the first link I came across MI424WR-GEN3I Issues A firmware upgrade did not help one of the people complaining about it but it might be worth a try if your firmware is out of date on it. Easy fix to do anyway.

If you log into the router and go to" Wireless Status", you should see Wireless Mode and likely Mixed but based on what I am seeing for this model is that its so old that it does not support Wireless-N. N is backwards compatible but if they are connecting to this AP built into this Modem/Router then they are connecting at Wireless-G at a best data rate of 54Mbps or a throughput of best half that at 26Mbps or less. Your best bet is to upgrade that FiOS Router/Modem to something much newer. Im not a Netgear Fanboy but I do know that as a consumer grade Wireless router from them also integrates with their other devices that provide additional coverage such as an Range extender. They work hand in hand with each other that allows roaming throughout the entire house. Both devices just need to broadcast the same wireless network name on the same channel and they can handoff your connection from one AP to the next smoothly. Might be worth looking into that next.

[ua549]

Transmit power is limited to 1 milliwatt by law. Power can be reduced but not increased above that limit. The default setting is full power. It is best to locate the router as high as possible in a centrally located position. That said, 7 year old equipment is most likely using 802.11g which is very slow and 3 generations old. Here are typical specs for each wifi version.

802.11 SPECIFICATIONS
                  Max     Indoor  Channel
         Bands   Speed    Range    Width
         (GHz)   (Mbps)   (ft)     (MHz)

 11ac        5    1300     230    20/40/80/160
 11n    2.4, 5     450     230    20/40
 11a         5      54      95    20
 11g    2.4         54     170    20
 11b    2.4         11     150    

Max Speed for 802.11 n & ac varies depending on the
number of antennas.  Speed for 3 antennas is shown. 
802.11 a b & g  use only 1 antenna.
Range will vary depending on obstructions.

There are some things you can do to with hardware improve your network.
Connect the router to the repeater with an Ethernet cable. The throughput will increase significantly.
Upgrade the wifi adapter where possible. There are USB wifi "n" adapters for less than $10.
If your router supports a guest network, you can split into an 802.11n only network and an 802.11 b & g network only.
That way you'll have a network for the slower devices.
To reduce the effects of interference use only 20 MHz wide channels on the 2.4 GHz band (ch 1 - 11).

[nbackus08]

Transmit power is limited to 1 milliwatt by law. Power can be reduced but not increased above that limit. The default setting is full power. It is best to locate the router as high as possible in a centrally located position. That said, 7 year old equipment is most likely using 802.11g which is very slow and 3 generations old. Here are typical specs for each wifi version.

802.11 SPECIFICATIONS
                  Max     Indoor  Channel
         Bands   Speed    Range    Width
         (GHz)   (Mbps)   (ft)     (MHz)

 11ac        5    1300     230    20/40/80/160
 11n    2.4, 5     450     230    20/40
 11a         5      54      95    20
 11g    2.4         54     170    20
 11b    2.4         11     150    

Max Speed for 802.11 n & ac varies depending on the
number of antennas.  Speed for 3 antennas is shown. 
802.11 a b & g  use only 1 antenna.
Range will vary depending on obstructions.

There are some things you can do to with hardware improve your network.
Connect the router to the repeater with an Ethernet cable. The throughput will increase significantly.
Upgrade the wifi adapter where possible. There are USB wifi "n" adapters for less than $10.
If your router supports a guest network, you can split into an 802.11n only network and an 802.11 b & g network only.
That way you'll have a network for the slower devices.
To reduce the effects of interference use only 20 MHz wide channels on the 2.4 GHz band (ch 1 - 11).

Well said!

[Emerald Acid]

Sadly, running Ethernet cables through the house isn't an option due to the distance the signal booster is from it. Otherwise I'd just Ethernet from my room straight to the router already.

I'll see what I can do about a router model upgrade, but I don't have high hopes, since the one in charge of it is a super stubborn "We're not changing anything" type of person.

Doesn't seem to be a Guest Network option for the router.