5G Network performance engineer

Randstad Technologies; City Of London; Hybrid; GBP 92,000 - 148,000; Full time

Job summary

Randstad Technologies is seeking a 4G/5G RAN Performance & Optimisation Expert to support ESN in a London-based hybrid role. You will shape performance strategies for 4G/5G, define KPIs, and drive action plans to uplift network efficiency across interworking scenarios.

The role requires deep RAN expertise with Nokia and Ericsson, proficiency in LTE/SIP, SRTP/DTLS, and drive-test analysis. You will collaborate across SMEs and suppliers to deliver robust RAN designs and ESN readiness.

Qualifications

• Extensive experience as a Performance SME in 4G/5G/5G+ networks.
• Expert understanding of SA, NSA, VoNR, and Slicing architectures.

Responsibilities

• Drive 4G/5G ESN performance management, define SLAs/KPIs, and build action plans for continuous performance uplift.
• Lead feature and parameter optimisation trials across Nokia and Ericsson RAN, assessing network impacts and quantifying gains.
• Conduct root cause analysis of performance degradation using drive test logs, Wireshark, OSS data, and CN protocol analysis (OSI L1-L7).
• Investigate and resolve issues in 5G SA/NSA interworking, ESN PTT over SRTP, and End-to-End network performance.
• Collaborate with SMEs, stakeholders, and 3rd-party IT/Network suppliers to deliver fit-for-purpose RAN designs.

Skills

4G/5G RAN expertise

Nokia & Ericsson RAN

SLA/KPI definition

LTE/SIP signalling

SRTP/DTLS troubleshooting

Drive test analysis

Cross-functional collaboration

Change impact assessment

Tools

Nemo

TEMs

Accuver

Actix

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.