Loss of signal over and over and over again

I have attempted to write this three times, and each time the signal has gone away. AND AS I AM WRITING THIS - IT DID IT ONCE AGAIN. FOUR TIMES IS ENOUGH. It is 1:53 am. And this happens just about every night. I work from home, and I generally work late into the night or morning. I would like to know why this is happening and if it will ever stop happening. I AM GETTING REALLY TICKED.