iPhone 4 antenna is smart but also being notorious for having antennagate issues. Apple confidently introduced the iPhone 4S with using completely same design of iPhone 4. No doubt it is a beautiful smarthphone but they better have fixed the death grip issue on antenna this time.
I stay in a place where the signal strength is moderate. Mobile phones do easily out of coverage in this certain areas but will back on line once there is network coverage. On the first day I get my hands on the iPhone 4S, it displays 'No Service' but doesn't search back the signal. I can't send SMS and make calls. I have to manually turn on and off the Airplane Mode to trigger it to search for signal. It happened every few hours and it's really irritating.
After searched the web, I found that this is a very popular issue. Many believe the iOS 5.0.1 firmware is the reason that causes the iPhone fails to search for network signal. I can't prove it because when I receive my iPhone 4S, it's already with iOS 5.0.1 (9A406). Apple has provided a solution for iPhone 4S which has symptoms that difficult in recognizing a micro-SIM card resulting 'No Service' or 'Searching' in a location with good network coverage. Trying this resolution is better than none. I follow the instructions and restored my iPhone 4S but the 'No Service' issue still exists.
It leaves me hopeless and wait for a newer firmware updates which able to fix this problem (probably iOS 5.1?) but who knows? They might never fix it. At this moment, I just try my best to avoid my iPhone 4S from dropping the signal strength to 'No Service'. Otherwise, I will have to switch on and off the Airplane Mode to wake it up to search for network signal.
Now is almost a week of using the iPhone 4S, it seems it's able to automatically search back the network by itself after the status bar dropped to 'No Service'. I don't know why it's back to normal as I didn't do anything to fix it. Is it iPhone 4S antenna needs to 'warm up' first for a period of time? But my iPhone 4S has none of this issue indeed after a week of usage.