As the Internet of Things (IoT) wave sweeps the globe, we are living in an unprecedented era of "interconnected everything." According to relevant data, the number of IoT devices worldwide is experiencing explosive growth, expected to reach billions or even tens of billions in the next few years. However, traditional physical SIM cards are increasingly showing limitations in deployment, management, and cost when dealing with the massive, diverse, and widely distributed IoT devices. It is against this backdrop that eSIM (embedded SIM) technology has emerged. It revolutionizes the connection between devices and networks in a disruptive way, injecting strong momentum into the large-scale development of the IoT.

I. What is eSIM?

eSIM, short for Embedded Subscriber Identity Module, integrates the functionality of a traditional SIM card directly into a secure chip (eUICC) on the device's motherboard. Compared to traditional SIM cards that require physical insertion and removal, eSIM's "card information"—i.e., the operator profile—can be remotely downloaded, activated, switched, and deleted over the network.

This transformation brings three core advantages:

1. Flexibility and Convenience

Users or device administrators can switch operators or plans online "remotely" without replacing a physical card. For outbound travelers, they can purchase and activate a data plan for their destination before arrival, saving time and effort by avoiding the need to find a physical SIM card at a local store. For IoT companies, multiple network options can be pre-configured for devices sold globally, enabling "global single SKU" production. The device can be activated locally wherever it is located, greatly simplifying supply chain and inventory management. For example, a multinational corporation producing smart sensor devices doesn't need to manufacture different versions for each country; it only needs to activate the corresponding carrier profile locally.

2. Space Optimization and Enhanced Reliability

The eSIM chip is significantly smaller than a traditional SIM card (e.g., 2mm x 2mm), saving valuable internal space for small devices like smartwatches and sensors. Because it's directly soldered onto the circuit board, its shock resistance, high-temperature resistance, and waterproofing far surpass those of physical cards, making it more suitable for harsh environments such as industrial applications and connected vehicles. In some industrial scenarios, devices need to operate in high-temperature, high-humidity, and high-vibration environments. Traditional SIM cards may malfunction due to poor contact, while eSIM chips can operate stably, improving device reliability.

3. Enhanced Security

Based on Public Key Infrastructure (PKI) and secure domain isolation technology, eSIM ensures end-to-end encryption of the profile from generation and distribution to storage, effectively preventing risks such as physical card theft and SIM card swapping attacks, providing a more robust "digital identity" security guarantee for devices. In the era of the Internet of Things (IoT), device security is paramount, and the security features of eSIM technology can effectively protect the data security of both devices and users.

II. The Popularization and Application of eSIM

1. Consumer Electronics: Pioneers of eSIM Popularization

Consumer electronics are pioneers in the popularization of eSIM. Apple's latest iPhone 17 Air (A3518 model) was the first in the Chinese mainland market to adopt a "pure eSIM" design, eliminating the physical SIM card slot. This marks a new stage in the development of the eSIM ecosystem in China. Users can activate cellular services directly by scanning a QR code or through the operator's app, experiencing unprecedented convenience. This move has promoted the development of eSIM services in China, and more and more users are beginning to understand and use eSIM technology.

Meanwhile, the smartwatch sector has long been a "testing ground" for eSIM applications. Taking the OPPO Watch X2 series as an example, it supports China Mobile's "One Number, Two Devices" service, allowing the user's watch to share the same number and data plan as their phone. This means that even if users go out for exercise or attend meetings without their phones, the watch can still independently make and receive calls, receive messages, and use the cellular network, truly achieving the freedom of "independent online access." This "watches first, phones follow" strategy is accelerating the adoption and awareness of eSIM among consumers.

2. IoT Field: The Broad Application Prospects of eSIM

The wider application scenarios for eSIM services may not be limited to mobile phones, but rather the Internet of Things (IoT). For example, connected vehicles can be integrated with eSIM cards. Connected vehicles need real-time network connectivity to obtain traffic information, navigation data, etc. eSIM technology can provide stable and reliable network connections for connected vehicles, while also supporting remote upgrades and management. Furthermore, eSIM technology can play an important role in smart homes, industrial sensors, and other fields. Smart home devices are numerous and widely distributed; eSIM technology can enable remote configuration and management of these devices, improving the intelligence level of smart home systems. Industrial sensors need to operate in harsh environments; the reliability and security of eSIM technology can meet the needs of industrial sensors.

III. The Future of eSIM

1. Technological Development Trends

Technically, the SGP.32 standard for IoT will further simplify the process of remote device management and reduce the complexity of deploying massive numbers of devices. The integration of eSIM with technologies such as 5G, network slicing, and edge computing will enable eSIM to provide differentiated, high-quality connectivity services for various scenarios. For example, under 5G networks, eSIM technology can achieve higher data transmission rates and lower latency, meeting the needs of applications such as high-definition video and virtual reality. Network slicing technology can provide dedicated network resources for different IoT applications, improving network security and reliability. Edge computing technology can handle data processing and analysis locally on the device, reducing data transmission latency and costs.

2. Policy Support and Market Prospects

At the policy level, China's Ministry of Industry and Information Technology has clearly stated that it will comprehensively promote the application of eSIM technology in various fields, and the three major telecom operators have also gradually resumed and promoted eSIM mobile phone services by 2025. This policy clarity has cleared obstacles for the healthy development of the industry. According to GSMA Intelligence, there will be approximately 1 billion eSIM-enabled smartphone connections globally by the end of 2025, growing to 6.9 billion by 2030, accounting for 76% of all smartphone connections. Jupiter Research estimates that by 2026, the number of IoT connections using eSIM technology globally will grow from 22 million in 2023 to 195 million. These figures demonstrate the vast market potential and enormous growth potential of eSIM technology.

eSIM is not merely a small technological upgrade; it represents a profound connectivity revolution. It liberates control of connectivity from the physical world, returning it to users and administrators. Through "software-defined connectivity," it paves the way for the large-scale deployment, intelligent management, and global operation of the Internet of Things. From smartphones to autonomous vehicles, from smart cities to smart factories, eSIM is becoming a key cornerstone in building a future intelligently connected world, ushering in a new era of more flexible, efficient, and secure connectivity.