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.