Completion of Full Virtualization of the Mobile Core Network

NTT DOCOMO, INC. (hereafter DOCOMO) has completed the full virtualization*1 of its mobile core network (hereafter core network), which serves as the foundation for providing mobile voice and data communication services used by over 90 million customers, in conjunction with the network equipment switchover and the termination of third-generation (3G) mobile communication services implemented by the end of March 2026. With this, DOCOMO's core network transitions from a configuration dependent on conventional dedicated hardware to one that implements functions as software on general-purpose servers, evolving into a more flexible, highly stable, and cost-saving communication infrastructure. [Image: Overview Diagram] **■ Background** Conventional core networks were built using dedicated hardware for each function, making the time required for equipment expansion and configuration changes, as well as the need for rapid on-site maintenance work during equipment failures, significant issues. To solve these issues, DOCOMO initiated basic research on network virtualization in 2005. From 2014, it promoted international standardization at standard organizations such as ETSI*2 and 3GPP*3, succeeding in verification experiments in 2014*4. Subsequently, in March 2016, DOCOMO launched the world's first commercial operation running multi-vendor EPC*5 software on an integrated virtualization platform*6. The company has progressed in stages to build a network not dependent on specific hardware, keeping pace with technical advancements and standardization trends across the telecommunications industry. DOCOMO continued to migrate networks in alignment with the replacement timing of existing equipment, and has now achieved the full virtualization of the entire core network. **■ Overview of Full Virtualization** Virtualization introduces a virtualization layer (hypervisor or container virtualization) on general-purpose servers instead of dedicated equipment, allowing various functions that make up the core network to operate as software. Full virtualization is a mechanism that enables flexible control and operation of the entire network by virtualizing all equipment comprising the network. This makes it possible to change equipment configurations and optimize function placement through software control. **■ Effects** By fully virtualizing DOCOMO's core network, it evolves into a highly flexible configuration less subject to physical constraints. **• Improved Communication Reliability** Even in the event of an equipment failure, auto-healing*7 is immediately executed across the entire core network. This automatically detects anomalies in the software or hardware comprising the network and restarts/reconfigures the functions on other healthy virtual resources. This shortens the period of single-system operation and contributes to the provision of stable communication services. **• Enhanced Agility in Expanding Equipment Capacity** It becomes possible to share general-purpose hardware across multiple systems and flexibly utilize available resources from the integrated platform's resource pool. This reduces the time required to secure equipment capacity needed when launching new services or during traffic surges. Furthermore, in the event of natural disasters, auto-scaling automatically expands the capacity of network equipment to improve connectivity.