@Hop2013: Is the issue only occurring when you're in that particular location in your house, or do you encounter it elsewhere? When it next occurs, try removing any cases or covers on the device to see if this helps. Also, press the Volume Down and Power buttons together for around 10 seconds until the phone restarts to address any software issues that might be a contributing factor. Don't worry, this won't affect your personal data or settings. You may also wish to try heading to Settings > General management > Reset > Reset network settings > Reset settings, although please be aware that this will also reset your Wi-Fi, Bluetooth and Mobile Data settings.
@Hop2013: I can completely understand your frustration. If your mobile network signal is fine in all other locations, then this does suggest that there is a network black spot in your house that is causing the signal to drop. For clarity, do you get a white circle with a line through it in your Status Bar, where your signal bars should be? Alternatively, do you get any notifications that you're not connected to a network? Next time the issue occurs, swipe from the top of the screen to the bottom and toggle Flight Mode on, then off again to see if this helps. I understand that you haven't experienced the issue while using the same SIM in another device, however I do encourage you to continue to troubleshoot the problem, especially if it is limited to a certain location.
