Without knowing what all the equipment is, it's difficult to comment.
So many thoughts go through my mind with a topic like this.
Problems could be related to hardware device, cables, wireless channels, firmware, interference, mis-configuration, and so on.
So, try to eliminate possibilities with your troubleshooting. Try another browser, computer, OS, etc.
One of the simplest ways to eliminate a bunch of things is to plug a notebook into the wireless router. If it works perfectly, then you need to spend time with the wireless router configuration and one of your wireless devices.
You also need to get some type of wireless activity app, like inssider. These apps let you walk around and watch what happens to your signal as well as the other wireless devices and routers in the area.