Periodic disconnections are normal. Normaly, your router will automaticaly disconnect after prolonged idle time: Time when there is no trafic.
Whenever you attempt any internet access, the connection will be automaticaly reestablished. The only impact will be a slight delay that you may not even notice.
It's possible that the allowed idle time is set to short.
Access your router configuration page. Somewhere, you'll find the allowed idle time. Increase it to around 60 minutes.
The specific layout change from brand to brand, and even model to model of the same brand.
Consult your router's manual to find your specifics.
Also, as you have a whireless router, there may be outside interferences.
If you have a desktop computer, it's normaly beter to connect it with an ethernet cable. If it don't have an ethernet connector, an ethernet card is usualy less than $15 and is about the truest plug and play device you can find. Power off, plug in, power on and it's ready to use. Those normaly come with one ethernet cable of reasonable lenght.
Try using another wi-fi channel.
Try relocating the router. Place it well away fron any air conditioner unit, the fridge and any electric motor.
Electro
August 2011