On my PHL-IAH flight last week the system would hiccup (screen went blank then a searching for signal message popped up and then finally it came back) for about 15 seconds every 10 minutes or so. I could understand if it was an isolated area but it occurred prior to takeoff, during takeoff and midflight. Although not as bad as my EWR-ORD flight when we ventured up into Canada and only the CO channels were available for 90% of the flight