WiFi Connection With Phone/xbox

Is your ISP throttling you? Does this only happen during a certain time period?

You might have the modem checked or a cable technician come out and measure the 'noise' in your cables.

If you have many splits and splices in your cable, it can cause interference. I was having issues with low speed, turns out my router was getting signal through five spots, tech rerouted that to two. After that, we got a new router and modem. Our modem was also faulty. So that's a possibility too.

Not sure how TWC handles it but Cox basically covers you to the modem, so long as you buy their modem. Router is our problem.

EDIT: Rereading, I'd check the router. Our old one used to disconnect my phone at random. We never figured out why. This was over two phones; an iPhone 4S and a Moto X 2013. Other family members were having the same issues with their phones but never their computers.

Personally I'd move it away from other devices.

I'd also get my own modem and router and not use the crap that is supplied by the ISP.

At the least you could attempt changing channels, and 2.4ghz (unlike 5ghz) propagates through walls easily enough, so I doubt strength is an issue unless you have lead lined walls, or are too far (however having a ups right beside it probably isn't a great idea, but I wouldn't expect it to be causing issues, but it could, potentially).

Ultimately it sounds like the wifi is ***on the device and you need a new one, especially if wired is working fine.

edit: reread; if the wifi is going out for everything periodically when you're doing a particular action then it is probably crashing and restarting the radio and/or service on the router, whether that's by design from the ISP or a defect is hard to say, but it sounds like it's an issue with that device. Fortunately they're required by law to let you use your own, so have fun shopping (or have them replace it, but you're most likely better off having your own, especially if you're at the level of at least knowing what an SSID is).

I didn't say that the modem was resetting entirely, just the wireless and since your desktop is wired and not experiencing these issues, it's what it sounds like.

If the signal is dropping on multiple devices at once then your wifi is dropping out. Yeah there are tools to test it from a laptop and stuff but why bother on a single device?

A cause could be that the band is saturated and it's autoswitching to another channel, but that shouldn't cause a disconnect unless it is just really that crappy of a device.