5G Network performance engineer

Randstad Technologies Recruitment; City Of London; Hybrid; GBP 80,000 - 120,000; Full time

Job summary

Randstad Technologies Recruitment seeks a skilled 4G/5G RAN Performance & Optimisation Expert for a 6-month contract in London. The role focuses on ESN performance management, SLAs, and cross-vendor RAN optimisation to ensure a robust emergency services network.

You will analyse drive-test data, SNMP-like KPI trends, and interworking scenarios, delivering actionable recommendations to stakeholders in a hybrid London setting.

Qualifications

• Extensive experience in high-availability 4G/5G networks with SA/NSA, VoNR, and Slicing.
• Hands-on knowledge of Nokia and Ericsson RAN counters, KPIs, and parameters.
• Strong LTE/SIP signalling and SRTP/DTLS troubleshooting skills.
• Ability to translate complex data into clear change proposals for technical and business audiences.
• Proactive mindset to keep up with 3GPP/ETSI specs for future networks.

Responsibilities

• Drive 4G/5G ESN performance management and define SLAs/KPIs.
• Lead feature and parameter optimisation trials across Nokia and Ericsson RAN.
• Perform root cause analysis using drive tests, Wireshark, OSS data, CN protocol.
• Investigate and resolve ESN PTT over SRTP and 5G SA/NSA interworking issues.
• Collaborate with SMEs, stakeholders, and third-party IT/Network suppliers on RAN designs.

Skills

Performance SME

RAN optimisation

Root-cause analysis

LTE/SIP signalling

Cross-functional collaboration

Network design foresight

Tools

Nokia RAN counters

Ericsson RAN counters

Nemo

Accuver

Actix

TEMs

Job description

Advert

Job Title: 4G/5G RAN Performance & Optimisation Expert (ESN)

Duration: 06 months with possibility of extension

Location: London-Hybrid

Why This Role Matters

Join us and play a critical role in maintaining our position as a leading UK mobile network and driving our vision to be a global top-ten network. In this role, you will directly impact our current and future network efficiency, shaping the Mobile RAN strategy and ensuring a flawless subscriber experience-particularly for the highly critical Emergency Services Network (ESN).

What You'll Be Doing

• Performance Leadership: Drive 4G/5G ESN performance management, define SLAs/KPIs, and build action plans for continuous performance uplift.


• RAN Optimisation: Lead feature and parameter optimisation trials across Nokia and Ericsson RAN, assessing network impacts and quantifying gains.


• Deep-Dive Analysis: Conduct root cause analysis of performance degradation using drive test logs, Wireshark, OSS data, and CN protocol analysis (OSI L1-L7).


• Technical Troubleshooting: Investigate and resolve systematic issues in 5G SA/NSA interworking, ESN PTT (Push to Talk) over SRTP, and overall End-to-End network performance.


• Cross-Functional Collaboration: Work closely with key SMEs, stakeholders, and 3rd-party IT/Network suppliers to deliver \"fit for purpose\" RAN designs.

What You'll Bring

• Expertise in Mobile Networks: Extensive experience as a Performance SME in high-availability 4G/5G/5G+ networks, with expert understanding of SA, NSA, VoNR, and Slicing architectures.


• Vendor Knowledge: Deep, hands-on experience with Nokia and Ericsson RAN counters, KPIs, and parameters.


• Protocol & Tool Proficiency: Strong knowledge of LTE/SIP signalling, SRTP/DTLS troubleshooting, and familiarity with test/post-processing tools (Nemo, TEMs, Accuver, Actix).


• Analytical Storytelling: The ability to convert highly technical data into compelling, simple-to-understand cases for change for both technical and business audiences.


• Forward-Thinking Vision: A proactive approach to network design, keeping ahead of telecom market developments and 3GPP/ETSI specifications to build the networks of the future.