Why does my Sun Broadband Wireless always disconnects automatically?

Why does my Sun Broadband Wireless always disconnects automatically?

I’ve already ask about this at the Sun Shop but they just checked thew settings of my device and asked if I get a good amount of signal in our area. The answer is yes. The device always shows blue light which indicates connection. But whenever I connect it, after 2 minutes to 15 minutes, it disconnects automatically. Where does the problem lies? Is it the device itself? or the network? Any ideas or solutions to this?