After upgrading to 8.3, the locked 4s brush machine of US Telecom can't make phone calls and send messages, indicating that China Telecom can't have network service, so it changed the card sticker.

From the description, your mobile phone should be the V or S version of the iPhone 4S. It is difficult for these two operators to understand officially. What card is your card sticker? If it is GPP, I can give you the following suggestions. Scan the QR code to install GPP 3to2 in GPP official website software download, download GPPLTE unlocking assistant, follow the above steps, take out the SIM card and insert it again, and wait for a period of reaction time. If it's not a GPP card, you can take out the SIM card and turn it off, then try plugging it in. If it doesn't work, you can only change the card sticker. If there is a lock, don't upgrade it. Card stickers may not be able to unlock the upgraded system perfectly!