Why can't my telecom card Apple 4s 3g send short messages in the morning and at noon? What happened?

The telecom version of iphone4 can't make phone calls or surf the Internet when there is a signal. General operators cannot provide services normally. The specific reasons for the check are as follows: 1, check the internet access parameters, and then go to Settings-General-Network in turn to check whether the cellular data switch is turned on, or the capital "e" is not used on the right side of China Mobile LOGO before the call, and confirm that the column of cellular data APN is "cmnet". 2. Confirm whether there is a "description file". In actual use, a description file may be automatically installed when installing network-related applications such as bank clients or other third-party VPN tools. Some description files will affect the online function, so it is suggested to delete them. 3. Confirm whether the operator patch is installed. IPhone jailbreak operation itself will not directly affect the Internet access function of mobile phones, but some users can't access the Internet after jailbreak, and then install operator patches. Even if the operator patch is installed, there is still a problem accessing the Internet. In this case, it is suggested to delete the relevant patch of the operator, restore the network settings and reset the access point. Method of restoring network settings: Settings-General-Restore-Restore network settings.