I did it, the network then came back for a while. After few minutes, the problem was back again, eventually, my iPhone4S said: "SIM Failure". I tried to attach my SIM card to a NOKIA mobile and iPhone3GS (iOS4.x.x), it runs perfectly for all day long without any issue.
After searching on the internet, I'm pretty sure that this is a problem of iOS. Apple, please do something ...
Here are some observations and a suggestion.
1) I mentioned before, that the number of views of this discussion forum is fast approaching 100,000. I suppose relative to all iPhones sold that is not a great percentage, but 100,000 still sounds pretty impressive to me. Consider also that many people probably have this same Sim problem and are not viewing this discussion forum because thay do not know it exists. How many people are REALLY experiencing this problem? Who knows. But I suspect it is more that 100,000.
2) To the best of my knowledge, Apple does not consult these forums as a guide to awareness of product performance. It may be company policy, but most of the time when I speak to an Apple employee they seem remarkably unaware of the "Top Stories" in the Apple Discussion Forum. This, despite the fact that my personal experience with customer service at Apple is excellent. So, as much as we of this discussion forum are confident SOMEONE important at Apple is reading all our posts and taking them to heart...I am not so sure.
3) I have been told over and over that the best way to gain Apple's attention regarding a problem is to post a comment on their Feedback Site. One comment about a problem is pretty worthless. 100,000 comments on the same issue, I'm guessing, will really get their attention.
4) Some folks have mentioned a recall to address this problem. Although such a thing is always a possibility, I don't see it happening. Why? When the brakes on a Toyota don't work, or that Toyata starts to accelerate without driver intention...well, that involves human life and the stakes are quite high. For many reasons you would see the automotive industry eventually be forced into a recall program under such a situation. But, a phone APPEARS to not nearly be such a life and death device. Or is it? My daughter's iPhone 4S developed a "SIM FAILURE" on the same day her car broke down in the middle of the very rural area we live at around 10:00 pm. She is 17 years old and was coming home from high school play practice. You can imagine the anxiety I and her mother felt when she did not arrive home on time. She eventually walked about a quarter mile to a house of a stranger and had to ask to use their phone to call us. Now, I am not saying that strangers where I live are not to be trusted. But, in addition to being worried out of my mind, I was not happy that an inoperative iPhone 4S caused my daughter to be put in this situation. My biggest concern now is...when will my daughter's iPhone become inoperative again due to SIM FAILURE?
5) The more folks in this discussion forum who post a comment about this issue in Apple's feedback site the more pressing this issue is going to be perceived by Apple. So, I like others, encourage all of you to do so. If this seems like a lot of effort, I offer you these few sentences below that you could just copy and paste into the feedback site.
The link to feedback site is: http://www.apple.com/feedback/
Feel free to use copy/amend/whatever the following as you wish:
I wish to register a strong concern about my iPhone's unpredictable inoperability due to failures somehow associated with it's SIM technology. For me, I do not consider this just a significant lack of convenience, but a significant safety issue. Should I need my phone in an emergency situation where it is experiencing a SIM FAILURE, I believe the iPhone will have put me at risk. I would ask you to please give fixing this problem your greatest priority and effort.