why do I always lose the signal and network?!

[kathead]

Hi, I have always had Samsungs, and recently swapped from Samsung Galaxy Y to Galaxy Ace thinking I had a phone problem. My phone works fine until I step through the door at work. I have no network coverage (altho website says it is fine in that area) and have no signal. Is something interfering with the signal at my workplace ? My very old cheaper Samsung phone has a signal and can receive calls so why not the new models? Any help much appreciated. thanks