Have you checked your internet speed?
Your internet provider may not be supplying enough speed or your modem may be failing.
In a way iOS 7 may be part of the problem. It demands good internet speed and connection to function.
Modems and routers have a life span also.
If your modem and router is older (4-5 years) it may not be keeping up. They don't die a sudden death, they tend to work intermittently requiring resetting often. If you find resetting your router and or modem helps, and it happens more often, it is those devices failing.
Next.... Placement of your router makes a difference.
Placing a router on your top floor and trying to connect in a basement doesn't work. The signal from a router fans up and out. Imagine an invisible cone from the router extending upwards and out. Reception is best when not blocked by metal beams or other wireless signals.
My AirPort Extreme is in my basement and covers my 3 story home to all ends and the yard close to the house.