Designer

Hiring: Mobile Core Voice Signalling Designer

Reading (Green Park) | Hybrid (2 days onsite)

Contract: Initial 6 months (rolling extensions highly likely)

£580 MAX

Start: ASAP

We are looking for a true hands-on Mobile Core Signalling Designer to join a major transformation programme across Voice Core and Subscriber Data Management.

This is not a high-level architecture or “buzzword” role. We need someone who has designed, migrated, and delivered real signalling solutions in live mobile networks.

What you will be doing:

You will sit within the signalling design team, owning and driving end-to-end design across core voice signalling environments, including:

• Producing HLDs & LLDs for signalling platforms
• Designing migrations from legacy/bare metal → cloud (VNF/CNF)
• Leading signalling architecture decisions across:
• Ericsson DSC (DRA/DEA) → 5G signalling controller evolution
• IPSTP consolidation & virtualisation
• Supporting subscriber data migrations:
• Retiring HLR/HSS
• Moving to Nokia SDM
• Designing traffic migrations, integrations & new platform builds
• Collaborating with vendors on SORs, SOWs & compliance reviews
• Driving automated testing for call flows (5G SA + legacy)
• Ensuring designs meet capacity, security, and fraud requirements

You will work both independently and as part of a wider programme team, helping steer technical direction and delivery outcomes.

What you need (non-negotiable)

We are looking for deep, hands-on experience, not surface-level exposure:

Ericsson Signalling (ESSENTIAL)

• DSC (Diameter Signalling Controller)
• IPSTP
• HLR / HSS

Nokia SDM (ESSENTIAL)

• Strong experience with Nokia SDM
• Subscriber data flows & migration experience
• Vendor-to-vendor migration understanding (e.g. Ericsson → Nokia)

Core & Signalling Expertise

• Strong knowledge of:
• SS7, SIGTRAN, SIP, Diameter, MAP
• Solid experience across 2G / 3G / 4G / IMS / 5G
• Proven ability to design core network signalling solutions
• Experience producing reliable design documentation (HLD/LLD)

What will make you stand out

• Experience with VNF → CNF transformations
• Private cloud / cloud-native signalling deployments
• Strong understanding of traffic modelling & capacity planning
• Ability to challenge vendors and validate designs
• Someone who can walk into a technical interview and own the detail

Working environment

• Hybrid: Tuesdays & Wednesdays onsite (Reading)
• Working closely with senior designers and leadership
• Exposure to CTO-level stakeholders, vendors, and industry partners
• High autonomy — you’ll be trusted to deliver and lead design decisions

Important

This role involves a deep technical interview (“grilling”).

We are specifically looking for candidates who can demonstrate real design ownership, not just familiarity.

📩 Interested?

Apply direct.

If you have worked on real-world signalling design, migrations, and Nokia SDM transformations, this is the kind of role where you’ll have genuine impact on a live mobile network evolution.