In a prose divorce. How long should you wait for a response?

my ex husband and I have been separated for more than 3 yrs. after all this time I have finally put together the money for a prose divorce, I sent him the papers and waiver for a basic divorce over a month ago and am wondering how long I should wait before I have him served...I know that he is not signing these papers to make things difficult. He was a physically and emotionally abusive man and tho to others he appears well adjusted and charming, he would honestly do anything for revenge. I'm not sure what my next step is, but for my safety and that of my kids I can not do anything in person...we have already had to move a state away