NTT DOCOMO’s Journey of Network Virtualization with OpenStack

DOCOMO’s Network Evolution by NFV

The concept of DOCOMO’s Network Functions Virtualization (NFV) is centered on transforming traditional, manual hardware maintenance operations into API-driven operations enabled by NFV with OpenStack. This approach preserves existing operational workflows while significantly reducing operational impact and complexity.

By introducing MANO APIs on top of OpenStack, DOCOMO enabled faster and easier maintenance at the hardware layer. This model has since been extended beyond the core network to additional domains such as RAN, maximizing the benefits of NFV through unified operations, enhanced automation, and a unified platform architecture.

In the expansion phase, DOCOMO extended virtualization to additional network functions such as IMS, HSS, and enterprise PBX, supported by unified and automated maintenance models. By 2018, this approach had matured with OpenStack evolution.

In the evolution phase, DOCOMO developed 5GC and vRAN platforms using container-based architectures, enabling cloud-native operations and the use of Generic VNFM.

Scale and Growth of Virtualization

DOCOMO adopted a strategy of migrating end-of-life network functions