APN (Access Point Name) is the name of a gateway between a GPRS (or 3G, etc.) mobile network and another computer network (usually the Internet). A mobile device must be set up with the access point name provided by the operator in order to create a data connection.
Carriers use this name to distinguish the type of network connection that will be created, such as what IP addresses will be assigned to wireless devices, or how security will be used, and whether or how to connect to some private customer network.
The wireless module APN adaptation refers to the technology that the mobile device can confirm the information of different SIM cards and automatically set the APN information when the SIM card of different operators is replaced.
In the traditional application, when the GPRS data service is involved, the APN is set by the AT command provided by the wireless module manufacturer. The actual use of terminal equipment is not restricted by countries and regions, resulting in various APN settings.
This will put pressure on customers. Terminal products are generally consumer-oriented. If you get the product, you need to set the APN, user name, password, etc., which obviously weakens the user experience.
If the wireless module user completes the collection of APNs by himself, it will take a lot of time to sort out, and a certain amount of resources will be wasted. Under this series of problems, some wireless module users hope that wireless module supplier will solve them.
Related concepts: International Mobile Subscriber Identification Number (IMSI: International Mobile Subscriber Identification Number) is a sign that distinguishes mobile users, and is stored in the SIM card and can be used to distinguish valid information of mobile users. Its total length does not exceed 15 digits, and the numbers from 0 to 9 are used, which is composed of MCC+MNC+MSIN. MCC is a 3-digit mobile country code, and MNC is a mobile network code consisting of 2 or 3 digits.
The MCC+MNC in the international user identification code is the operator code, that is, the operator code. In most cases, an operator code corresponds to a unique APN, which is a one-to-one correspondence. In rare cases, one operator code corresponds to several APNs, or different operator codes correspond to the same APN. For example, China Mobile's 46000 and 46002 access points are both CMNET. The access point corresponding to 46000 may be CMNET or CMWAP. CMWAP is only used in mobile phone applications, and wireless module applications can eliminate this and reduce the workload.
The IMSI number can be obtained through the command AT+CIMI after the SIM card is successfully initialized. At the same time, in the platform, the IMSI number can also be obtained through the callback interface during the initialization process. Suitable conditions are created for APN adaptation.