Industry October 22, 2025 MOBITELSMS Engineering

The State of 5G Rollout

Despite the marketing push, the global 5G landscape in late 2025 remains dominated by Non-Standalone (NSA) deployments. The majority of operators that have launched "5G" commercially are running Option 3x: 5G New Radio (NR) on the air interface, anchored to an existing 4G LTE Evolved Packet Core (EPC) for all control-plane functions. The user equipment connects to a 5G cell for data throughput, but session management, mobility, authentication, and charging still flow through MME, HSS, and PGW -- the same 4G nodes that have been running for a decade.

Standalone (SA) deployments, where the entire core is replaced with a cloud-native 5G Core (5GC) based on 3GPP Release 15/16 service-based architecture, are still emerging. A handful of operators in the US, South Korea, China, and parts of Europe have launched SA commercially, but global SA coverage remains limited. For MVNOs, this distinction is not academic -- it determines whether the 5G transition is a radio upgrade you can mostly ignore, or a fundamental rearchitecture of your interconnect, billing, and subscriber management.

NSA vs SA: What the Difference Actually Means

In an NSA deployment, the 5G NR radio is added as a secondary cell group (SCG) to an existing LTE master cell group (MCG). The anchor LTE eNB handles the control plane, and the 5G gNB provides an additional data pipe. From the core network's perspective, nothing changes. The MME still manages session state. The HSS still authenticates subscribers. The PGW-C/PGW-U still handles data routing and charging. Diameter Gy/Ro interfaces still handle online charging. S6a still connects to the HSS. GTP tunnels still carry user data.

For an MVNO with a light or full MVNE integration, NSA means minimal impact. Your existing MVNO core interconnect -- whether it is based on Diameter, RADIUS, or a proprietary API from your host MNO -- continues to work. Your SIM cards do not need replacing (4G USIM profiles are sufficient for NSA). Your charging records look the same. Your subscribers get faster data speeds, but your operational infrastructure stays put.

SA is a different story entirely. The 5G Standalone Core introduces a service-based architecture (SBA) where network functions communicate over HTTP/2 with JSON payloads instead of Diameter and GTP. The core network functions are completely new:

What SA Means for MVNO Operations

If your host MNO migrates to SA, or if you plan to deploy your own core, several operational areas are affected.

New Interconnect Agreements

Your MVNO-MNO interconnect contract likely specifies Diameter-based interfaces (S6a for subscriber data, Gy/Ro for charging, Gx for policy). In a 5GC, these are replaced by HTTP/2-based service interfaces: Nudm for subscriber data, Nchf for converged charging (the N40 reference point), and Npcf for policy. Existing Diameter interconnect agreements need renegotiation, and your MVNE or billing platform needs to speak HTTP/2 with 3GPP-defined JSON schemas.

SIM Card Changes

5G SA introduces SUPI (Subscription Permanent Identifier) and SUCI (Subscription Concealed Identifier) to replace IMSI-based identification. While SUPI can be an IMSI in format, SUCI adds a public-key encryption layer that requires new SIM profiles (5G-capable USIM with the MNO's home network public key provisioned). For MVNOs that issue their own SIMs, this means a SIM swap program. For those using host-MNO SIMs, the host handles it, but you need to verify your BSS/OSS can process SUPI-based identifiers.

Charging Interface Migration

The 5GC Charging Function (CHF) replaces the legacy OCS. Instead of Diameter Gy Credit-Control-Request / Credit-Control-Answer exchanges, charging uses HTTP/2 POST to the Nchf_ConvergedCharging service, with JSON-encoded charging data records. The fundamental model (request units, use them, report) is similar, but the wire protocol is completely different. Any MVNO running its own online charging system needs to add HTTP/2 + JSON support alongside (not replacing) its existing Diameter stack, since 4G traffic will coexist for years.

Roaming in a 5G SA World

5G roaming introduces two new architectural elements that MVNOs need to understand. First, the SEPP (Security Edge Protection Proxy) is mandatory for inter-PLMN signaling. SEPP provides application-layer security for all SBA messages crossing network boundaries, replacing the relatively open Diameter/SS7 interconnect model. Second, NRF-based service discovery means that roaming partners must register and expose network functions through a federated NRF model. IPX (IP eXchange) providers are evolving their offerings to support 5G roaming, but the transition is not seamless.

For MVNOs, the practical impact is that roaming agreements need updating. If your host MNO handles roaming on your behalf (common for light MVNOs), you are shielded from SEPP complexity but may see changes in charging record formats. If you operate your own core, you need to deploy SEPP and establish new inter-PLMN agreements with roaming partners, which is a significant undertaking.

Voice: VoNR, VoLTE Fallback, and the Long Tail of CS

Voice over 5G remains one of the messiest parts of the transition. Three models coexist:

For MVNOs, the voice strategy depends heavily on the host MNO's network. If they support EPS Fallback (most do), voice works without any changes on your side. If they push VoNR, you need to ensure your IMS integration and billing can handle VoNR-originated sessions, which may carry different QoS markings and charging characteristics.

Open-Source Core Options

One of the most compelling developments for MVNOs is the maturation of open-source mobile core implementations. Three projects stand out:

These projects give MVNOs the option to self-host core network functions instead of leasing them from an MNO or MVNE. The economics work for operators with 50,000+ subscribers, where the cost of engineering staff to manage the core is offset by eliminating per-subscriber MVNE fees.

Spectrum Sharing: MOCN and MORAN

5G introduces more flexible spectrum sharing models that can benefit MVNOs. Under MOCN (Multi-Operator Core Network), multiple operators share the same RAN (radio access network) and spectrum, but each runs their own core network. This is the most common sharing model and allows MVNOs with their own core to get direct radio access without building towers. Under MORAN (Multi-Operator RAN), operators share the RAN but use separate spectrum allocations, giving more isolation but less spectral efficiency.

For MVNOs, MOCN is the more interesting model. If regulatory frameworks in your market allow it, MOCN sharing with an MNO gives you radio access with full control over your core, subscriber data, and billing -- a significant step up from traditional MVNO models that depend entirely on the host for network functions.

Network Slicing: The MVNO Opportunity

Network slicing is arguably the most MVNO-relevant 5G SA capability. A network slice is an end-to-end logical network, running on shared physical infrastructure, with dedicated QoS guarantees, security isolation, and independent lifecycle management. In theory, an MNO could provision a dedicated slice for each MVNO, with guaranteed throughput, latency, and capacity -- moving beyond best-effort traffic sharing.

In practice, commercial slice offerings for MVNOs are still in early stages. The technology works (3GPP Release 16 defines NSSF, S-NSSAI identifiers, and slice-specific authentication), but the business models, SLA frameworks, and operational tooling are still being developed. MVNOs should be tracking slice capabilities in their host MNO agreements, even if activation is not immediate.

Investment Timeline: What to Do Now vs. 2026-2028

Given the current state of the industry, here is a practical prioritization for MVNOs:

How MOBITELSMS Supports the Transition

MOBITELSMS is built to operate across the full spectrum of network generations simultaneously. The platform includes a complete 4G EPC integration for existing MVNO deployments, a 5G SA core based on 3GPP Release 16 for operators moving to standalone, Diameter Gy/Ro/Gx charging for 4G traffic, HTTP/2-based converged charging for 5GC, and an SS7 signaling gateway for legacy interconnect with 2G/3G networks that have not yet been decommissioned.

This multi-generation approach means MVNOs can migrate incrementally. Start with 4G EPC billing today, add 5G SA charging when your host MNO is ready, and maintain SS7 interconnect for markets where legacy networks persist. The routing engine, CDR pipeline, and subscriber management layer work identically across all access technologies, so the migration is a configuration change, not a platform replacement.