My wife and I have definitely done our fair share of time apart because of my job. I have been in Singapore for the last two months whilst my wife is at home in Muscat, although I have just nipped back for 48 hours as my son was ill but currently in Colombo Airport Lounge on the way back to work.
It takes commitment and communication to handle being away, and gets harder (not easier) over time, so I try to spend as little time away as possible now.
Viber, whatsapp, skype, email etc all make life much more tolerable. Occasionally for various reasons I have to go on a communication blackout for short periods and that really is more difficult then you would think
If you have found the right person, you will overcome all obstacles together.