Why 3G Shutdown Changes Everything For MVNO Lawful Interception
Mobile network operators across Europe are shutting down their 3G networks. For most subscribers, this means faster data and better coverage on 4G and 5G. But for Mobile Virtual Network Operators (MVNOs), the transition creates an unexpected compliance challenge: they must now implement their own lawful interception infrastructure for the first time.
Under 3G circuit-switched networks, MVNOs relied on their host MNO to handle lawful interception. Voice calls ran through the MNO’s circuit-switched core, and the MNO’s existing LI systems captured everything. MVNOs had no direct LI obligation because they had no direct control over the voice infrastructure.
That model breaks down when 3G disappears.
From Circuit-Switched To IMS: The Technical Shift
With 3G decommissioned, voice services migrate to VoLTE (Voice over LTE) and VoNR (Voice over New Radio for 5G). Both technologies deliver voice as IP packets over the data network, using the IP Multimedia Subsystem (IMS) architecture.
Many MNOs require MVNOs to operate their own IMS cores rather than sharing the MNO’s IMS infrastructure. This gives MVNOs more control over service features, billing and customer experience. But it also means the MVNO now directly controls voice call signaling and media – making them the entity responsible for lawful interception.
The regulatory framework is clear: whoever operates the communication service must provide lawful interception capability. When the MVNO operates the IMS core that processes voice calls, they become the lawful interception obligor, not the host MNO.
What MVNOs Must Implement
MVNOs transitioning to their own IMS infrastructure need a complete lawful interception solution that covers:
Warrant Management
A system to receive, validate and track lawful interception requests from law enforcement agencies. This includes managing target identities (MSISDN, IMSI, IMEI), warrant timelines and authorized agency access.
IMS Interception Points
Integration with the IMS core to collect Intercept Related Information (IRI) and Content of Communication (CC) for VoLTE and VoNR calls. This requires interception functions at the P-CSCF, S-CSCF and other IMS elements.
Mediation And Formatting
A mediation platform that normalizes data from IMS nodes and formats it according to ETSI TS 102 232 specifications, specifically ETSI TS 102 232-5 for IP multimedia services.
Transferência segura
Encrypted delivery channels (HI2 for IRI, HI3 for CC) to law enforcement monitoring facilities, with mutual authentication, delivery confirmation and audit logging.
Compliance Reporting
Documentation and reporting capabilities to demonstrate compliance during regulatory audits and respond to agency inquiries about interception status.
Building this infrastructure in-house requires specialized expertise in 3GPP standards, ETSI LI specifications, IMS architecture and law enforcement interface requirements – expertise most MVNOs don’t have on staff.
Three Paths Forward For MVNOs
MVNOs facing this challenge have three main options:
Option 1: Build In-House
Hire LI specialists, purchase mediation software, integrate with IMS elements and establish LEA connections. This gives maximum control but requires significant capital investment, ongoing operational costs and the ability to keep up with evolving standards.
Option 2: Managed LI Service
Outsource the entire LI operation to a specialist provider like ICS. The provider operates the mediation platform, manages warrant lifecycles, handles LEA handover and takes responsibility for compliance. The MVNO maintains oversight but avoids building specialized infrastructure and hiring dedicated staff.
Option 3: Software Platform With Support
License LI management and mediation software and run it on your own infrastructure, with implementation support, training and ongoing consulting from an LI specialist. This middle path gives you control while leveraging external expertise for setup and maintenance.
Most MVNOs find that managed services or supported software platforms offer the best balance of compliance assurance, cost control and operational simplicity. The business case for building in-house only makes sense at significant scale – typically several million subscribers.
Don’t Wait Until The Last Minute
3G shutdown timelines vary by country, but the trend is clear: circuit-switched voice is ending, IMS is the future, and MVNOs need their own lawful interception solutions. Regulators expect compliance from day one of IMS operation – there’s no grace period for MVNOs to “figure it out later.”
ICS helps MVNOs navigate this transition with flexible solutions that fit your timeline, budget and technical environment. Whether you need a complete managed service, integration support for IMS interception or consulting to understand your obligations, we provide the expertise to ensure you remain compliant as your voice infrastructure evolves.
The 3G shutdown is forcing a change. Make sure lawful interception doesn’t become the surprise roadblock in your IMS migration plan.
Contact ICS to discuss your MVNO lawful interception requirements and explore the right solution for your IMS deployment.