@Decorah 

The first step would be to rule out location and enviroment.  To do this set the camera up close to the router and in an area with clear line of sight and no barriers between the router and the camera.  If the issue presist then change the 2.4GHz channel, most routers may be set to Auto, which can at times switch to a congested channel.  the channels with the least ammount of interference from other channels are 1, 6, and 11 although you may need to try each as they are also the most common used channels.  

After trying these and if the camera successfully stays connect relocate it back to where you want to use it.  If it begins to have issues, relocated back to where it was working and if it starts working again you will know the desired area is in a poor location and a Range Extender may be needed to improve the service.