My long distance boyfriend has not contacted me for more than a month. Should i assume it's over?

I met my boyfriend while he was on an exchange to Australia at my school. We were really good friends for the whole of his year and a half exchange and we started going out a few months before he was due to go home to Switzerland. I thought I could handle letting it go when he left but we became so close that neither of us could handle breaking up. We Facebook mailed and skyped fairly often at the start and he would always say how much he was missing me and loved me, but as he got busier and time went on he got more and more distant when he would talk to me and contacted me less and less. It got to the stage where he wouldn't reply to my mail and would only talk to me if I happened to be online on Facebook chat. Now he hasn't talked to me for more than a month, even though I kept mailing him and even txtd his phone. We've been together for around 7 months now, and I came to accept that we both had to live our own lives and couldn't be messaging etc 24/7. But this is just too much. I wouldn't even mind not talking to him if he would just let me know he was busy or couldn't talk, but he just won't say anything to me. He could have died for all I know. I just want to have my thoughts straightened out so I know where I stand, whether were together or not, but last time I checked, just ignoring someone isn't a clear way of breaking up. Should I just break up with him to make it clear what our status is? He was the sweetest most sensible and mature person, I never would have thought he would break up with me in this way if that's what he's trying to do. I was sure he would be brave enough to just tell me his feelings. I'm just confused and want to be out of this unsure situation. What should I do?