Cellular network

2026-02-28

Cellular Network is a wide-area network architecture based on wireless communication, widely used in mobile communication and IoT devices. Its core feature is dividing the coverage area into multiple "cells", with each cell served by a base station providing wireless access. Terminal devices connect to the operator's core network through the base station, enabling voice, SMS, and data services.

This chapter mainly introduces the method of connecting to the network using USIM.

Dual SIM dual standby is supported, but this document only focuses on USIM.
Only 4G LTE networks are supported.

Hardware connection

  • SIM card slot
    Nano SIM plug-in card slot.

  • SIM card antenna interface
    IPEX-4TH antenna connector.

Quick start

Boot up

Enter the system and check whether the SIM card is recognized correctly. If recognized correctly, the display will appear as shown below.

Network confirmation

Use adb to enter the system and ping 8.8.8.8 to confirm whether the network is connected properly. For adb usage, please refer to the Getting Started chapter for adb instructions.

Function usage

Enable cellular network

Swipe down from the top of the screen, and the drop-down menu will display the Internet option. Tap to select the corresponding LTE toggle switch and turn it on (lit up).

Disable cellular network

Swipe down from the top of the screen, and the drop-down menu will display the Internet option. Tap to select the corresponding LTE toggle switch and turn it off (dimmed).

Common issues

  1. The wireless network card is successfully activated, but network services cannot be used. What could be the reason?
There are generally two possible reasons for this issue: **SIM card arrears (out of credit)** - Some SIM cards allow the module to register on the network and activate the cellular wireless network card even when out of credit. However, the carrier will block actual data communication. **APN configuration issues** - The SIM card supports access to a specific network through a particular APN, and the user has configured the APN for this specific network. In this case, the device connects to the specific network instead of the internet. If the user attempts to access the internet under these circumstances, the operation will fail. For specific APN configuration, go to `Settings -> Network & Internet -> Internet -> CMCC (connected/LTE) -> Access Point Network`, and configure a new APN for internet access.