Core Viewpoint - The communication industry in China has achieved a historic breakthrough with the successful launch of the first cross-operator traceable VoWiFi call between China Telecom and China Unicom in Shandong, addressing issues related to weak cellular network coverage indoors [1][18]. Summary by Sections VoWiFi Technology - VoWiFi (Voice over WiFi) allows users to make voice calls over WiFi networks, solving issues in areas with poor cellular coverage [8][9]. - Unlike VoLTE (Voice over LTE) and VoNR (Voice over New Radio), which rely on 4G and 5G networks respectively, VoWiFi operates independently of cellular signals, requiring only a WiFi connection [8][9]. Historical Context - The first end-to-end traceable VoWiFi call was successfully made by Shanghai Telecom on May 20, 2022 [4]. - VoWiFi services had not been officially launched in China due to regulatory challenges regarding traceability [9]. Technical Innovations - A dual-factor authentication system was developed to ensure reliable traceability and security for VoWiFi calls, achieving higher precision than VoLTE [10]. - The cross-operator traceable VoWiFi solution has been recognized by experts from the Ministry of Industry and Information Technology and the China Academy of Information and Communications Technology [10]. Market Implementation - Following the announcement of VoWiFi by China Telecom in 2022, pilot programs were initiated in five provinces in 2023 [11]. - Users in cities like Guangzhou and Shenzhen can now experience this service, provided their devices support it [14]. User Experience and Benefits - VoWiFi can enhance call quality in areas with weak cellular signals, providing clearer and more stable communication compared to traditional voice calls [17]. - The service is automatically activated when mobile signals are poor, ensuring seamless connectivity [18]. Industry Impact - The technology has been adopted by both major operators and is set to become an industry standard under the China Communications Standards Association (CCSA), promoting collaborative development across the sector [19]. - The implementation of this technology not only expands the user base for VoWiFi but also opens new communication pathways in remote areas and special scenarios [19][20].

Group 1 - The article discusses the evolution and significance of dual SIM card functionality in mobile phones, highlighting its origins and the role of Chinese manufacturers in popularizing this feature globally [1][3][5] - The introduction of low-cost chip solutions by companies like MediaTek significantly reduced manufacturing costs, enabling the rapid proliferation of dual SIM phones [3][6] - The demand for dual SIM functionality in China is driven by factors such as varying telecom package costs, the need for separating work and personal numbers, and differences in network coverage among operators [8][10] Group 2 - The article explains the technical aspects of dual SIM technology, including the two main modes: DSDS (Dual SIM Dual Standby) and DSDA (Dual SIM Dual Active), detailing their operational differences [15][17][19] - DSDS allows both SIM cards to be on standby but only one can be active for calls or data at a time, while DSDA enables simultaneous use of both cards for calls and data [19][21] - The advancements in VoLTE and VoNR technologies have enhanced the quality of voice and video calls over 4G and 5G networks, respectively, improving the dual SIM user experience [23][25] Group 3 - The evolution of SIM card sizes from Mini-SIM to Nano-SIM has facilitated the physical implementation of dual SIM functionality in smartphones [29][30] - The design of SIM card slots has transitioned from fixed internal slots to more user-friendly removable trays, allowing for better space management within devices [30][33] - The emergence of eSIM technology represents a significant shift, eliminating the need for physical SIM slots and enhancing device waterproofing and user convenience [37][40][41]

Core Insights - The mobile core network (MCN) market experienced a year-on-year growth of 19% in Q2, with the 5G segment growing by 31% and the voice core segment by 18% [2] - The growth of 5G standalone (5G SA) networks is driven by an increase in the number of users and mobile network operators (MNOs) launching more 5G SA services, with 71 MNOs confirmed to have launched 5G SA services for consumers [2][5] - The adoption of new technologies such as NR RedCap and dynamic network slicing is expected to enhance the performance and reduce costs for IoT devices connected to 5G networks [2][8] Market Growth and Projections - The growth rate for the MCN market is projected to double to 10% by 2025 due to strong performance in the first two quarters of the year [2] - Despite only 10% of MNOs having launched 5G SA, the core space is accelerating due to the low penetration rate of 5G SA users, with only 14% of mobile users expected to have 5G SA services by the end of 2024 [5] - The revenue for 5G MCN is expected to grow at a compound annual growth rate (CAGR) of 6% from 2024 to 2029 [7] Technological Advancements - The introduction of NR RedCap is anticipated to lower costs and improve performance for IoT devices, with new 5G smartwatches expected to launch soon [8] - Multi-access edge computing (MEC) is also seeing significant growth, with a 32% year-on-year increase in Q2 2025 and an expected 44% growth for the year [11] - The integration of new voice technologies such as VoNR with cloud-native IMS Core is enhancing user experience and driving growth in voice core and 5G packet core markets [9] Industry Trends - MNOs are increasingly recognizing the potential of cloud-native networks, leading to upgrades in voice core systems, which is contributing to market growth [2][9] - The trend of migrating 5G core workloads to public cloud options is re-emerging, allowing MNOs to evaluate the best solutions for their markets [10] - The use of artificial intelligence in network operations is expected to drive demand for more core capacity as MNOs offer advanced AI tools to customers [9][10]