Telecoms Core Network Engineer

About the RoleShape the future of secure UK telecoms At UK Telecoms Lab, we are building the UK’s leading capability for telecoms security testing, research and resilience. We provide a secure, independent environment where complex telecoms systems can be integrated, tested and evaluated to help protect the UK’s critical national infrastructure. We are looking for an experienced Telecoms Core Network Engineer to provide, maintain and evolve the core lab environment that underpins advanced security research. You will bring deep technical knowledge of mobile core 4G and 5G network functions, host architectures, virtualised environments and test tooling, and use that expertise to support supplier design reviews, integration, acceptance, testing, maintenance and operations. About The Role This is a hands-on technical leadership role at the heart of UKTL’s lab capability. You will act as a design authority for core network systems, hosts and test tools, ensuring the environment is secure, reliable, well documented and ready to support vulnerability research, penetration testing and evaluation activity. You will work closely with suppliers, research teams, evaluation teams and security testing specialists to introduce new components, influence supplier roadmaps, resolve complex technical issues and continuously improve the lab environment as telecoms technology evolves. What You’ll Be Doing Design, develop, integrate and maintain 4G/5G core network systems, host environments and test tools. Act as the design authority for lab systems, ensuring solutions are secure, resilient and fit for research and evaluation needs. Own functional testing, fault-finding, troubleshooting and resolution across complex lab environments. Support supplier design reviews, integration, acceptance, testing, maintenance and operational activities. Work with suppliers to influence technical roadmaps and evaluate new components for future lab evolution. Maintain the lab security posture, including reviewing and approving third-party exports where required. Support vulnerability research, penetration testing and evaluation teams by advising on required features and activating or deactivating capabilities as needed. Set documentation, quality and delivery standards, ensuring activity is planned, recorded and updated using appropriate delivery tools. Lead or supervise small teams and cross-functional projects, coaching less experienced colleagues and providing technical direction. Identify and implement continuous improvement opportunities across systems, processes and ways of working. Successful Applicants must be able to commute to the UKTL offices in Birmingham at least twice a week We strive to offer a great work life balance - if you are looking for full time, part time or flexible options, we will try to make this work where business possible. This will be dependent on the kind of role you do and part of the business you work in. About You We are looking for someone with strong technical credibility, a collaborative mindset and the ability to explain complex decisions clearly to technical and non-technical audiences. You will understand how your work supports wider organisational and government objectives and be motivated by the opportunity to contribute to national telecoms security. Essential Experience And Knowledge Expert technical knowledge of 4G core functions, including MME, SGW, PGW, PCRF, HSS and IMS. Expert technical knowledge of 5G core functions, including AMF, SMF, UPF, NRF, PCF, SEPP, NEF, NSSF, AUSF, UDM and UDR, as well as service-based architectures. Expert knowledge of building and managing Kubernetes container environments and OpenStack-based hypervisors. Strong troubleshooting and fault-finding methodology across complex telecoms, host and virtualised environments. Experience of functional testing, analysis and reporting on technical, policy and security implications. Ability to break down planned activities into sprint deliverables and keep plans updated, particularly during and before sprint close. Experience leading small teams, projects or cross-functional technical activities. Clear written and verbal communication skills, including the ability to explain how decisions or conclusions have been reached. Beneficial Experience Familiarity with Radio Access Network architectures. Experience or awareness of security testing techniques. Interest in industry developments and their implications for government policy, telecoms resilience and cyber security. Why join us? At UKTL, your expertise will help protect the digital networks that people, businesses and critical services rely on. You will work on technically challenging, high-impact projects at the intersection of telecoms, cyber security, government, industry and academia, with access to structured development, mentorship and a supportive working environment. Please note: Applications will be reviewed, and interviews conducted throughout the duration of this advert therefore we may at any time bring the closing date forward. We encourage all interested applicants to apply as soon as practical. We actively recruit citizens of all backgrounds, but the nature of our work in this specific area means that nationality, residency and security requirements are more tightly defined than others. To work in this role, you will need to hold an SC clearance with no restrictions. You are welcome to apply without already holding SC clearance; however, you will not be able to start in post until the clearance has been successfully granted. About Us UKTL is building leading edge Telecoms testing facilities to keep our telecommunications networks safe, accelerate the roll-out of new technologies, and grow our world leading telecoms sector to maintain resiliency and security. Read more about UKTL here! Successful candidates will join a state-of-the-art facility and be supporting the team conducting testing and research on the latest technologies and innovations in the industry. You will work alongside our infrastructure and Cybersecurity professionals to ensure that the UK’s world class Telecoms infrastructure grows in a resilient and secure manner underpinning growth in other industry sectors. As a trusted and independent national capability, UKTL interacts with standards bodies, Academia, and Government Departments as well as Communications Service Providers and equipment vendors. The National Physical Laboratory (NPL) is a world-leading centre of excellence that provides cutting-edge measurement science, engineering and technology to underpin prosperity and quality of life in the UK. Find out more about what it is like working here - The measure of us - Overview NPL and DSIT have strong commitments to diversity and equality of opportunity, and welcome applications from candidates irrespective of their background, gender, race, sexual orientation, religion, or age, providing they meet the required criteria. Applications from women, disabled and black, Asian and minority ethnic candidates in particular are encouraged. All disabled candidates (as defined by the Equality Act 2010) who satisfy the minimum criteria for the role will be guaranteed an interview under the Disability Confident Scheme. At NPL, we believe our success is a result of the diversity and talent of our people. We strive to nurture and respect individuals to ensure everyone feels valued by treating everyone on the basis of their own individual merits and abilities regardless of their own or perceived identity, as part of our commitment to diversity & inclusion, we ensure we’re creating an environment where all our colleagues feel supported and welcome. More about this on our Diversity & Inclusion page. We offer a wealth of above industry standard benefits, such as enhanced pension scheme, flexible working, and more that can be found here rewards, benefits and recognition. Our values are at the heart of what we do, and they shape the way we interact, develop our people and celebrate success. To ensure everyone has an equal chance, we’re always willing