ON-X GROUPE

About the Company

ON-X, independent French consultancy and expertise firm, specializes in the integration of digital technology for companies, government agencies and local authorities. Profiting of 30 years of experience and three agencies (Paris, Toulouse, Montbeliard) to meet these new challenges, our firm is organized around 5 competence centers that support customers successively to define the transition strategy, to accomplish main stages of decision support, to design and drive their implementation projects and finally to control the services delivered. Our mission: to serve our customers in the long term, be a decisive player in the definition and implementation of digital transformation projects. Our competence centers: - Digital Infrastructure: cloud (IaaS), telecommunications & mobility, transition management, service management, TEM - Digital Security: governance, risk management, research and expertise, audit and penetration testing, awareness and training - Digital Territory: digital planning of territories, intelligent territories, infrastructures services and usages development for digital - Information System: urbanization of the information system, project owner assistance, IS governance and PMO (Project Management Office), architecture, software engineering - 3D: augmented and virtual reality, computer graphics, mobile & 3D applications, industrial design and conception (CAD), operational security and quality, training engineering

Listed Jobs

Company Name

ON-X GROUPE

Job Title

Ingénieur Réseau et Télécom (Téléphonie Mobile 4G / 5G) (H/F)

Job Description

**Job title** Network and Telecom Engineer (4G/5G Mobile Telephony) **Role Summary** Design, evolve, and validate 4G/5G mobile network architectures, develop test plans, conduct Proof‑of‑Concepts (POCs), and transfer knowledge to operations teams. Monitor technological roadmaps and security compliance to ensure network stability and performance. **Expectations** - Contribute to the design and evolution of mobile core network infrastructures (EPC, IMS, MCx, Messaging). - Author technical specifications and documentation. - Perform tests, validate results, and support the transfer of expertise to operations. - Stay current on industry standards, vendor solutions, and vulnerability management. **Key Responsibilities** - Analyze technical impacts of new solutions and align them with existing architecture. - Recommend technical choices to maintain stability and performance. - Draft requirements (cahiers des charges) and technical documentation. - Design, execute, and evaluate test plans and POCs. - Deliver training and knowledge transfer to network operators and administrators. - Participate in core‑network evolution projects. - Conduct ongoing technological surveillance (EPC, Messaging, MCx, etc.). - Evaluate vendor roadmaps and integrate new solutions. - Monitor vulnerabilities and support architecture compliance. **Required Skills** - Core mobile network: EPC, IMS, HSS, PCRF, Messaging, MCx. - IP networking and protocols: SIP, Diameter, SCTP. - Test and validation environments. - Virtualization: VMware, Docker, Kubernetes. - Linux operating systems. - Strong analytical and technical rigor. - Curiosity, autonomy, and innovative mindset. - Excellent written and verbal communication for documentation and technical exchanges. **Required Education & Certifications** - Bachelor’s or Master’s degree in Network Engineering / Telecommunications (equivalent to Bac+5). - First professional experience (internship, apprenticeship, or initial assignment) in 4G/5G mobile core network environments. - Relevant certifications in mobile networking (e.g., Nokia, Ericsson, or 3GPP certifications) are an advantage.

Lyon 1er arrondissement, France

On site

12-02-2026