Core Network-as-a-Service (CNaaS) lets organisations that do not own mobile spectrum, including MVNOs, eSIM providers, and IoT connectivity businesses, run a full mobile core network as a managed cloud service. It gives them direct control over subscriber management, routing, and network behaviour, without owning core hardware or holding a spectrum licence.

This guide explains what Core Network-as-a-Service is, who it is for, and what it typically includes.

What is Core Network-as-a-Service?

A mobile core network is the part of a network that manages subscribers and routes their traffic. It includes the HLR/HSS (the subscriber database that authenticates devices and stores their service profile) and the packet core (the systems that route and charge for data and voice traffic). Traditionally, only mobile network operators (MNOs) that hold spectrum licences have run this layer themselves.

Core Network-as-a-Service delivers the same function as a managed, cloud-native service. Stacuity Core is one example of this model: it gives organisations without their own spectrum the same level of network control as an MNO, delivered through a portal and API rather than owned infrastructure.

Why organisations outgrow reselling MNO connectivity

Most organisations that sell connectivity do not control it. They resell what an MNO gives them, on the MNO’s timelines, through the MNO’s processes, within the MNO’s limitations. For a growing number of MVNOs, eSIM providers, and IoT businesses, that model becomes a constraint on how quickly they can launch products, manage subscribers, or respond to customer needs.

Who needs Core Network-as-a-Service?

The typical Core customer is in one of four situations.

1. No core network, and ready to take control

The organisation currently relies entirely on MNO commercial relationships to deliver connectivity but has no core network of its own. It wants to move up the stack, owning the subscriber relationship, the routing decisions, and the network behaviour, without the infrastructure investment or the dependency on individual MNO processes. For a light MVNO, this is the path to operating as a full MVNO.

2. An existing core to replace or modernise

The organisation has a core network, but it is ageing, approaching end of life, or too rigid and expensive to operate at the speed the business demands. It needs to modernise without disrupting the services it already runs. Stacuity Core provides a migration path: real-time, software-defined control running alongside or replacing the legacy infrastructure.

3. Fragmented MNO relationships to consolidate

The organisation is managing separate relationships with multiple MNOs, each with their own contracts, processes, and limitations. It wants a single platform to centralise control, apply consistent policies across all of them, and reduce operational overhead. Stacuity Core provides a unified layer with a single portal and API, regardless of how many MNO integrations sit beneath it.

4. Outgrown existing capacity or capability 

The organisation’s current core infrastructure cannot scale to meet demand, whether in volume, in geography, or in the sophistication of control required. It needs a platform that grows with it, without hardware refresh cycles or vendor engineering timelines. Stacuity Core scales as a cloud-native managed service, so capacity and capability expand with the business rather than lagging behind it.

What does Core Network-as-a-Service typically include?

A Core Network-as-a-Service platform such as Stacuity Core generally provides:

  • HLR/HSS as a managed service. The provider integrates with the MNO partner’s network at the core level so the customer’s IMSIs can run on the platform.
  • Signalling visibility. Full visibility across SS7, Diameter, and GTP signalling.
  • Flexible charging options. A built-in OCS, integration with an external OCS via Gy, or delegated IP allocation via RADIUS, depending on what charging infrastructure the customer already has.
  • Programmatic control. Configuration available through both a portal and an API, in real time.

How MNO integration works

A Core Network-as-a-Service customer is the organisation that contracts with the provider and uses the platform. These are typically businesses that need a core network but do not own radio spectrum or operate their own HLR/HSS, including MVNOs, travel eSIM providers managing IMSIs across multiple MNO relationships, IoT connectivity providers needing real-time network control at fleet scale, and enterprise data providers building products on top of mobile connectivity.

Stacuity, for example, is already integrated with several tier 1 mobile operators, giving Core customers access to IMSIs from those networks from day one. Customers can also bring their own MNO relationship, in which case that operator’s HLR/HSS is integrated with the platform so its IMSIs run there too.

Core Network-as-a-Service vs owning physical infrastructure

Owning a core network used to mean owning racks of hardware, specialist engineering teams, and multi-year vendor commitments. Core Network-as-a-Service removes that trade-off: the same level of control over the network, delivered as a managed service, without the infrastructure burden.

Frequently Asked Questions (FAQs)

Core Network-as-a-Service is a model where a provider delivers the HLR/HSS and packet core functions of a mobile network as a managed cloud service, giving the customer network-level control without owning spectrum or core hardware.

It is typically used by MVNOs, travel eSIM providers, IoT connectivity providers, and enterprise data providers that need core-level network control but do not hold a spectrum licence or run their own HLR/HSS.

No. Core Network-as-a-Service is built for organisations without spectrum. The provider integrates with a partner MNO’s network, or with an MNO relationship the customer already holds, so the customer’s IMSIs can run on the platform.

Yes. A customer can bring an existing MNO relationship, and that operator’s HLR/HSS is integrated with the platform so its IMSIs continue to run through it.

Common options include a built-in OCS, integration with an external OCS via Gy, or delegated IP allocation via RADIUS, chosen according to what charging infrastructure the customer already has in place.