Mobile communication systems were born in the 1970s, but it was not until the 1990s that they became widely popular with the advent of the Global System for Mobile Communications (GSM), which is still widely used today. Mobile communication is a highly complex industry that integrates numerous advanced technologies. It has evolved from regional standards to global standards, and the widespread adoption of mobile communication has been facilitated by the establishment of these global standards. By setting unified standards, interoperability between different manufacturers' equipment, different network elements, different terminals, and different operators and users can be achieved. Through sharing, the costs of research & development and equipment have been significantly reduced on a global scale, making what was once a luxury accessible to ordinary households.