5G SBA, slicing, roaming, and service evolution
5G replaces many fixed appliances with service-based, virtualized, and dynamically scaled functions. Network slicing, roaming, non-public networks, edge services, and changing identity associations add lifecycle and correlation complexity. LI controls must follow the service without becoming visible to general orchestration or tenants.
Safety boundary: this chapter teaches lawful, governed system design from public standards. It does not provide operational targeting, activation, decryption, surveillance-evasion, or covert collection instructions.
The mental model
| Concept | Plain meaning | Control that must travel with it |
|---|---|---|
| SBA | Network functions interact through service-based interfaces | LI control remains isolated from general APIs |
| Network slice | Logical service partitions share physical platform | Tenant isolation does not automatically isolate LI |
| Roaming | Home and visited networks share service responsibility | Jurisdiction and handover responsibility are explicit |
| Dynamic NF | Instances scale, move, and restart | Authorized state is consistent and expires safely |
| Edge deployment | Service processing occurs nearer users | Trust, time, keys, and reachability span sites |
| Identity association | Identifiers change across service events | Correlation must be lawful, bounded, and time-aware |
Apply it as a controlled workflow
- Map service ownership and LI responsibility for home, visited, edge, and tenant domains.
- Keep LI administration outside ordinary discovery and observability surfaces.
- Define secure state distribution for ephemeral instances.
- Model lawful correlation across identifier changes without broad data pooling.
- Test slice movement, roaming changes, failover, and delayed state.
- Reassess coverage when 3GPP releases or service topology change.
Evidence to demand
- New instances cannot emit until current authorized state and time are proven.
- General orchestrator users cannot infer case existence.
- Roaming matrices name legal and technical delivery responsibility.
- Scaling, draining, and rolling upgrades have completeness reconciliation.
Failure to reason about
A network function is rescheduled to an edge zone whose certificate trust and time service are stale. The platform may serve ordinary traffic, but its LI path must fail safely and alert without revealing case information.
Feynman check
In 5G, the machines move and multiply. The lawful permission must reach exactly the right current machines, remain secret from ordinary operators, and disappear everywhere on time.