Role: Solution Design Specialist (Mobile Core)
Location: London (Hybird)
Duration: 6 Months
Day rate: £500 - £600 Inside IR35
We are seeking an experienced Mobile Core Design Specialist to lead solution design across 4G LTE and 5G Standalone (SA) Packet Core environments, supporting the delivery of critical national infrastructure programmes. This is a senior design role responsible for translating business requirements into robust, repeatable technical architectures aligned to enterprise guardrails and long-term strategy.
The Role
You will independently lead solution design workstreams, producing High Level and Low Level Designs (HLD/LLD) for Packet Core components and ensuring seamless integration across the wider network ecosystem.
You will act as a technical authority within design governance, shaping architecture decisions, mentoring other designers, and contributing to long-term mobile core strategy.
Key Responsibilities
- Design 4G and 5G SA Packet Core solutions, including: 4G: MME, GW-C, GW-U 5G SA: AMF, SMF, UPF
- Define and validate core interfaces and protocols: 4G: S1-MME/U, S4, S6a, S5/S8, SGi 5G SA: N-interfaces, Service-Based Architecture (SBA)
- Produce design artefacts including HLD, LLD, scope of works, and integration documentation
- Ensure alignment with Enterprise Architecture guardrails and solution patterns
- Support integration, testing, troubleshooting, and configuration management
- Act as technical authority within design governance and design authority forums
- Mentor team members and contribute to design best practices and thought leadership
Required Experience
- Strong knowledge of 3GPP 4G LTE and 5G SA Packet Core architecture
- Deep understanding of core network interfaces and signalling protocols
- Experience designing and integrating MME, GW-C, GW-U, AMF, SMF, UPF
- Knowledge of NFVI architecture and containerised network functions (Kubernetes)
- Solid understanding of IP networking principles
- Experience engaging business and operational stakeholders to translate requirements into technical designs
