Rakuten Mobile, Inc. and NEC to jointly develop the containerized standalone (SA) 5G core network

Japanese upstart carrier Rakuten Mobile, Inc. and NEC Corporation today announced that they have reached an agreement to jointly develop the containerized standalone (SA) 5G core network (5GC) to be utilized in Rakuten Mobile’s fully virtualized cloud native 5G network.

Based on the agreement, Rakuten Mobile and NEC will jointly develop the containerized SA 5G mobile core to be made available on the Rakuten Communications Platform (RCP), Rakuten Mobile’s fully virtualized and containerized cloud-native mobile network platform. The two companies will collaborate to build a Japan-made, highly reliable 5GC, based on the 5GC software source code developed by NEC. Subsequent to the launch of its non-standalone (NSA) 5G service in 2020, Rakuten Mobile aims to provide its SA 5G service in Japan in 2021.

The containerized 5GC will also play a key role in the global expansion of RCP, a platform aimed at offering solutions and services for the deployment of virtualized networks at speed and low cost by telecom companies and enterprises around the world, tailored for their unique needs. The 5GC will be offered as an application on the RCP Marketplace, allowing customers to quickly and easily “click, purchase and deploy” a fully virtualized SA 5G core network solution.


Editor’s Note:  The two companies don’t state what spec they’re using for their container based SA 5G Core Network 

–Please see Tareq Amin’s Comment below.

The only standards work we know of related to SA 5G Core Network is in 3GPP (5GCN), but it’s based on a NFV enabled network cloud and a service based architecturerather than containers.

We suggest that NEC contribute this spec to both 3GPP and ITU-T (for IMT 2020 non-radio aspects).  However, neither ITU-R or ITU-T has any serious ongoing work related to the 5G Core Network at this point in time.

The 3GPP specified 5G core network covers both wire-line and wireless access.  Key characteristics:

 Control plane is separated from the data plane and implemented in a virtualized environment
 Fully distributed network architecture with single level of hierarchy

 GW to GW interface to support seamless mobility between 5G-GW
 Traffic of the same flow can be delivered over multiple RITs

From the latest 3GPP Release 16 – TS.23501 5G Systems Architecture-V16.4.0 (2020-03):

The 5G System architecture is defined to support data connectivity and services enabling deployments to use techniques such as e.g. Network Function Virtualization and Software Defined Networking. The 5G System architecture shall leverage service-based interactions between Control Plane (CP) Network Functions where identified. Some key principles and concept are to:

– Separate the User Plane (UP) functions from the Control Plane (CP) functions, allowing independent scalability, evolution and flexible deployments e.g. centralized location or distributed (remote) location.

– Modularize the function design, e.g. to enable flexible and efficient network slicing.

– Wherever applicable, define procedures (i.e. the set of interactions between network functions) as services, so that their re-use is possible.

– Enable each Network Function and its Network Function Services to interact with other NF and its Network Function Services directly or indirectly via a Service Communication Proxy if required. The architecture does not preclude the use of another intermediate function to help route Control Plane messages (e.g. like a DRA).

– Minimize dependencies between the Access Network (AN) and the Core Network (CN). The architecture is defined with a converged core network with a common AN – CN interface which integrates different Access Types e.g. 3GPP access and non-3GPP access.

– Support a unified authentication framework.

– Support “stateless” NFs, where the “compute” resource is decoupled from the “storage” resource.

– Support capability exposure.

– Support concurrent access to local and centralized services. To support low latency services and access to local data networks, UP functions can be deployed close to the Access Network.

ITU-T SG13 is working on IMT 2020 non-radio aspects, but are heavily dependent on 3GPP documents to be liased in order to drive their future standards work in that area.  Unfortunately that has not happened.

Please see Comment in box underneath this article for GSMA Feb 2020 document on SA 5G Core option 2 guidelines for implementation.


“We are very excited to collaborate with NEC on the development of our standalone 5G core network,” commented Tareq Amin, Representative Director, Executive Vice President and CTO of Rakuten Mobile. “Our partnership with NEC represents a joint collaboration to build an open, secure and highly scalable 4G and 5G cloud native converged core, that will also become a key feature of the highly competitive services we will offer to global customers through the Rakuten Communications Platform.”

“NEC is proud to be the 5GC development partner for Rakuten Mobile’s advanced, fully virtualized, cloud-native network. Following the BSS/OSS for the 4G network and 5G radio equipment that we have already begun offering, we look forward to providing a high-quality, highly reliable 5GC and contributing to Rakuten Mobile’s 5G services,” said Atsuo Kawamura, Executive Vice President and President of the Network Services Business Unit, NEC.

Through the joint development of the SA 5GC, Rakuten Mobile and NEC aim to drive innovation in global mobile technology and provide high quality 5G network technology to customers both in Japan and around the world.

Rakuten Mobile CTO Tareq Amin clarification comments; via edited email to this author:

NEC/Rakuten 5GC is 3GPP standardized software for network service and a de facto standard container basis infrastructure (infrastructure agnostic).  It is a forward looking approach, but not proprietary.

1.  3GPP standardized software for network service:

NEC/Rakuten 5GC openness are realized by implementation of Open Interface defined in 3GPP specifications  (TS 23.501, 502, 503 and related stage 3 specifications).

2.   Containerization/Cloud native:

3GPP 5GC specification requires cloud native 5G core (5GC) architecture as the general concept (service based architecture).  It should be distributed, stateless, and scalable.  However, an explicit reference model is out of scope for the 3GPP specification. Therefore NEC 5GC cloud native architecture is based on above mentioned 3GPP concept as well as ETSI NFV treats container and cloud native, which NEC is also actively investigating to apply its product.

3.  Reference To Open RAN in the press release:

This has no relationship to 5G Core, but only an indication that our Radio Access Network (RAN) architecture is O-RAN Compliant.


Press Release:


Forward Reference:

Rakuten Communications Platform (RCP) defacto standard for 5G core and OpenRAN?

About Rakuten Mobile

Rakuten Mobile, Inc. is a Rakuten Group company responsible for mobile communications, including mobile network operator (MNO) and mobile virtual network operator (MVNO) businesses, as well as ICT and energy. Through continuous innovation and the deployment of advanced technology, Rakuten Mobile aims to redefine expectations in the mobile communications industry in order to provide appealing and convenient services that respond to diverse customer needs.

About NEC Corporation

NEC Corporation has established itself as a leader in the integration of IT and network technologies while promoting the brand statement of “Orchestrating a brighter world.” NEC enables businesses and communities to adapt to rapid changes taking place in both society and the market as it provides for the social values of safety, security, fairness and efficiency to promote a more sustainable world where everyone has the chance to reach their full potential.

more information, visit NEC at http://www.nec.com.


Rakuten, Inc. Corporate Communications Department
[email protected]

NEC Corporation Corporate Communications Division
[email protected]

5 thoughts on “Rakuten Mobile, Inc. and NEC to jointly develop the containerized standalone (SA) 5G core network

  1. GSMA on 5G Core Network:

    2.2.2 5G Core Network
    To offer new services, 5GC adopts new paradigm of core network as follows:
     New 5GC is expected to be a cloud-based system that leverages SBA to be more scalable and
     Separation of control plane and user plane allows better edge deployment for latency sensitive
    use cases.
     Data layer is categorized into Unified Data Repository (UDR) and Unstructured Data Storage
    Function (UDSF) to cover both structured data and unstructured data.
     Stateless Network Function (NF) enables common nature for greater robustness.
     4G/5G interworking via N26 interface between Mobility Management Entity (MME) and Access
    and Mobility Management Function (AMF) is standardized.
     Possibility for a User Equipment (UE) to be connected to multiple User Plane Functions (UPFs)
    simultaneously. For example, one remote (e.g., for a Data Network (DN) like Internet) and one
    close to the edge (e.g., for edge / low latency services).
    5GC SBA is based on a set of NFs providing services to other authorized NFs via service-based
    interfaces (SBI). The Network Repository Function (NRF) allows an NF to register itself and to
    discover the services offered by other NFs. All these interfaces are standardized and open.

    pg 14 of 5G Implementation Guidelines: SA Option 2, Feb 2020

  2. Rakuten commercially launched its new greenfield 4G network this past April in Japan. But the operator is already working on transitioning its network to 5G. And it plans to use containers, rather than virtual machines, for its network functions virtualization (NFV) infrastructure as well as part of its radio access network (RAN). Some of the vendors it’s collaborating with for containers include Robin.io, Altiostar and Intel.

    Rakuten is working with the Silicon Valley startup Robin.io — a five-year-old company with about 60 employees — to build its NFV container-based infrastructure.

    For its 4G network, Rakuten operates one horizontal cloud layer above its macro cell sites, edge data centers and central data centers. That cloud runs on Red Hat’s OpenStack (virtual machine) platform with contributions from Cisco.

    Rakuten is building its 5G cloud layer on containers. “When it comes to 5G, they want hyper-automation,” said Robin.io CTO Partha Seetala. The startup is providing several thousands of container clusters for Rakuten. Robin.io’s container software uses the Kubernetes container-management system.

    Asked why Rakuten didn’t just start with containers to begin with, Seetala said containers have matured quickly over the past couple of years, but he speculated that Rakuten probably started with virtual machines as a matter of expediency because that system was fully mature at the time it started its network build.

    “If you think about the 5G RAN core, it is different than the 4G RAN core,” said Seetala. “From the 3GPP, it is implemented as a micro-services-based architecture. For that they need to have a Kubernetes-based platform. So, they’re basically standing up another platform. The real estate is going to be the same data centers.”

    Other vendors working with Rakuten on its 5G build include Altiostar and Intel, which in February said they’re working with the Japanese operator to launch the world’s first container-based, cloud-native 5G radio access network (RAN).


    1. The Robin platform brings application-aware automation with built-in application-aware high-performance storage, ultra-high-speed networking, and data management features to support the demands of the new applications for IoT and wireless providers. Add intelligence, quickly adapt the software for different services, and automate to rapidly scale the network with the most efficient utilization of the hardware.

      Robin.io Builds Cloud-Native 5G, Edge Platform Using OpenNESS
      The Robin platform automates deployment, scaling, and life cycle management for data- and network-intensive applications on Kubernetes via application topology awareness that uses OpenNESS for 5G and edge services.



  3. Rakuten Mobile signed a deal to help U.S.-based Ligado Networks design a private 5G network that uses the Japanese operator’s customizable platform.

    The deal has the companies initially working to define a strategy that uses the Rakuten Communications Platform (RCP) and corresponding ecosystem to support Ligado’s L-Band spectrum holdings in the 1.6 GHz band. That work is set to begin this quarter and will target a 5G private network targeted at enterprise customers.

    Rakuten unveiled its RCP plans late last year. The platform is a combination of the operator’s various technical and intellectual property that it’s using to construct its software-centric network in Japan. The RCP model is focused on mobile operators, enterprises interested in private networks, and governments.

    Rakuten began demonstrating the RCP platform in August and claims it reduces capex for mobile operators by 40% and opex by 30%. Rakuten CEO Hiroshi Mikitani, at the time, said the global market for a platform like RCP, including traditional network costs for mobile operators, reaches up to $375 billion annually.

    Details on the work with Ligado remain light, though that should be expected considering Ligado’s history.

    Ligado currently provides mobile satellite service to government and commercial users in North America. It has been working with the federal government for years to use its spectrum assets to provide terrestrial service that can also tie into its satellite offering.

    The Federal Communications Commission (FCC) last month voted to deny a petition from the National Telecommunications and Information Administration (NTIA) that would prevent Ligado from commencing work with its spectrum holdings. NTIA had argued that the work would impact government GPS use. That FCC vote came one day before the agency’s previous head stepped down in alignment with the presidential administration change.

    Ligado’s spectrum concerns have been a long-running issue within the cellular community. Under its previous incarnation as LightSquared, it fought with the GPS community over potential interference issues in using its spectrum holdings for a terrestrial network. It eventually struck deals with a number of commercial entities in that community but also struggled through a complicated bankruptcy process and various attempts to partner with carriers and vendors to build out a cellular network.


  4. Rakuten Mobile launched full-scale commercial service on its 4G Open RAN network in April 2020 and aims to achieve 96% population coverage by the end of 2021. Altiostar developed the cloud-native, Kubernetes-based Open vRAN software that Rakuten Mobile used to build the network. The network is an industry-first for using cloud native software that converts Open vRAN network elements, including distributed units (DUs) and centralized units (CUs), into containerized applications that are fast to deploy, can be individually upgraded and offer better network scalability.

    “Winning these prestigious awards for such an innovative architecture is an important validation of Open RAN and a milestone for the industry,” said Ashraf Dahod, President and CEO of Altiostar. “I extend heartfelt congratulations to the entire Rakuten Mobile team. We are honored to partner with them, and this is great recognition for a team that had the vision for a new mobile network design in Japan and the boldness to pursue that vision.”

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