How to upgrade the wireless landline system between China and Norway?

The method of upgrading Sino wireless landline system is as follows:

1. Find system upgrade options on Sino-Norwegian wireless landlines, which can usually be found in the "Settings" and "About this phone" menus.

2. Connect the wireless landline and computer between China and Norway, using USB data cable or Bluetooth.

3. Download and install the system upgrade software of Sino-Norwegian wireless landline, which can generally be found in official website or other download websites.

4. Open the system upgrade software, follow the prompts, select the system version to be upgraded, and start the upgrade.

5. After the system upgrade is completed, disconnect the computer, restart the wireless landline between China and Norway, and check whether the system version is updated.