So I’ve been having wireless issues from the far end of my house and I even have a long range router and alfa wireless adapter. so I took my old router and flash ww-wrt onto it and messed with the settings. I’d recommend doing this on a old router because it can brick your router if you somehow **** up. make sure to read wiki.
this is what I did
- search for your router
http://www.dd-wrt.com/site/support/router-database - download the firmware upgrade file
- login to your router and select the file from your hard drive and upgrade it.
- once you’ve installed dd-wrt then login with the login you created
- go here [details=Open Me]
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and change it to how the image looks but change the SSID to the SAME as your router’s.
6)go to wireless security and adjust to how your main router is.
7)[details=Open Me]
[/details]
The local ip should be the same as your router but the last numbers altered to what you want to assign the router to.
Subnet mask should be same as router. As well as gateway and local dns the same as your main router’s IP.
Make sure you hit save after changing any settings then reboot the router afterwards. Now plug your xbox/any device in via ethernet and leech 
Any problems I can help troubleshoot if you post.
Sorry for messy layout 
Source : makeuseof