How can I get my 10 month old to sleep all the way through the night?

My son used to sleep through the night but for the last several months (since he was 6months old) he hasn't. We have tried swaddling him but he gets out. He never falls asleep with us in bed. I always rock him to sleep and he will stay asleep for about 3hrs but then wakes up and just stands up and cries. We have a baby monitor which has a camera on it so I can see him and see that hes ok. We go in and try to calm him down about ever 15 mins. We finally give up after about an hr and bring him into our room with us. Does any one have any suggestions?