Q: iPhone 4S dropping network and data at random

Mandachuva:  You need a USIM card, period.

My network by default does not use USIM cards but after 2 weeks let me have one.  This is the only long term solution.

On my third replacement now and this one finally works. I'm still using the exact same SIM that didn't worked on the other phones. This problem is definitely related to some kind of hardware malfunction/variation in batches.

Maybe it can be resolved in a firmware update addressing some circuit tolerances or other speculative reasons but I think you should consider replacing your device asap.

Maybe you are right hejo82, but my iPhone works perfect using another SIM "3G" card from other carrier. (ClaroBR here in Brazil). A hardware related issue, could bring the same symptom for all carriers.

@hejo82 And did you updated to iOS 5.0.1? I didn't have the issues until I updated so I doubt it's hardware related

I guess the most reasonable thing to do is to have your phone swapped. You can't really be sure if iOS 5.1 update is going to solve the problem. Theoretically each update should make things better but iOS 5.01 showed us we can't trust to much in Apple's developers skills. Probably the problem is not widespread and if you browse this forum take a notice that most of people complaining here are from outside USA. America is the most important market for Apple, so far, other markets probably comprise only a small percentage of Apple revenue so I wouldn't be suprised if Apple didn't  address the problem at all. It would probably be a waste of money for Apple to pay developers to solve the problem by tedious software designing instead of simply swapping a few phones. This is why I do not expect any explenations, apologies etc. from Apple at all. Heve your phone swapped instead of wasting time...that's what i am doing now, regards

Ok, a bit of progress for us in Australia. More info in this thread here:

http://forums.whirlpool.net.au/forum-replies.cfm?t=1794755

Seems there is a problem in Australia with the upgrades Telstra have done to their mobile network lately that are causing major havoc for the iPhone 4s. Not sure which of the worldwide providers are using LTE technology but the upgrades Telstra made have turned the iPhone 4s in major cities in Australia into an effective brick. Apparently Apple and Telstra have been working on this together to find a solution.

Now if only this news helped me, since I'm actually not with Telstra... and Optus don't seem to have LTE technology rolled out... but anyway. Progress is something!     

Hi there,

I have the same issue (I'm in Morocco) : losing network constantly. "no service" appears and only a restart make it back. I've tried everything : updated to 5.0.1, restored as a new phone, replaced the SIM card, disabled the PIN code, reset network settings, disabled data... but nothing has changed, still have the same problems.

Apple replaced my iphone 4s, and guess what .... still have the same issues with the new one... I don't know what to do.

I had something weard with both 4s, during the first week of use, every time I restart the phone I receive a pop-up sayin "I’m about to send this international message" to activate Facetime and iMessage. And when I checked my bill, I saw more than 30 sms to the UK linked to the activation...

I've called Apple, the'll replace my 4S again...

Very disappointed by the 4S. My previous iPhone 4 was much more reliable.

Cheers

I´m still looking to solve this, here is just an update...

A friend of mine has a fully working 4S using "identical" SIM card as me (same operator "VIVO", same card maker "GEMALTO"), I´m writting using "" because de SIM capacity isn´t printed on the card, and the 64K and 128K look exact the same. Today I will look for a 128Kb chip to replace mine (that I know is 64Kb), lets see whats next..

From a whitepaper by one of the leading manufacturers of SIM/USIM cards, Gemalto:

"There is a high chance that handset manufacturers, for economic reasons, will eventually stop supporting the SIM in their coming new 3G devices. As a consequence, if a 3G subscriber inserts a 2G SIM into a brand new 3G device, it will fail to connect to the network. There are examples where the SIM card becomes inactive in such conditions. In such circumstances, the 3G mobile operator stands to lose both current revenue on voice traffic and the potential revenue on new data services. To ensure quality of service for its new 3G customers, a major operator in France has proactively replaced their users SIM with 3G USIM cards: When sending a new 3G phone pack (including a USIM) to their current customers, this operator requested the user to insert the new 3G USIM into the new phone. The operator also warned the user that inserting a SIM into the new 3G phone could damage the SIM and crash the 3G phone software."

You can find the whitepaper here: http://www.gemalto.com/dwnld/5291_3G_network_WP_v4.pdf

I suspect that Apple (or more likely Qualcomm's chipset) may have stopped supporting 2G SIMs in the iPhone 4S. But that doesn't explain why it is working for some people and not others on the same network!?

Apple???  Answers please!

The 128K SIM don´t solve this problem, it is a normal SIM (not a uSIMor 3GSIM) but with 128Kb. Still the same :s

I sent in mine too and got a new and now it has worked for three days. I'm still using the exact same SIM that didn't worked on the other phones.

How many of you are here still waiting for a Apple´s solution?

Have you tried do use another carrier´s SIM on your iPhone? A lot of Carriers around the world choose not to use a 3G certified card because his a high price. I tried a PRE PAID "3G" chip from other carrier and my iPhone is working perfect..., I´ve contacted my carrier and, until now, they dont use a 3G SIM...

Have you updated to 5.0.1?

My SIM card is a 3G and it has been replaced twice. As I said, I used to have an iPhone 4 before the 4s, and it worked great, no such network issues. The update has not solve the problem.

What kind of information in your SIM makes it a 3G SIM?