Be sure he is eating to absolute capacity all day long. If hes waking up that much, he's not fully fed. Feed feed feed him. He may seem fine and full, but he would eat more if you offer. After a few days of increased calories all day long, you will see him sleeping much longer. I learned this trick from a mother of 12 who got all hers to sleep through by 3 months. It worked like magic for my daughter who was still nursing twice per night at 11 months. I stuffed her for a few days all day long, and like magic on the third night, she slept the whole night, and never woke up again during the night. It worked on my second 2 as well who we stuffed from and earlier age.
I would also start to leave him in his bed once he's more full. It is normal for the "45 minute friend" to strike somewhere between 45 minutes thru 1 1/2 hours and kids will wake up and cry, but if they're full, they'll go back to sleep in a few minutes. HIs ear issues are a factor, but this should help.