(IT) RAN Transmission Engineer

Flint is looking for a Transmission Engineer for a contracting opportunity with one of the main telco providers in the UK.

Key Responsibilities

• Own and manage the complete E2E performance lifecycle across RAN, IP transport/backhaul, and EPC/5GC domains.
• Develop and maintain performance baselines, KPIs/KQIs, and SLAs across all network layers.
• Lead complex multi-domain root cause analyses using cross-stack performance indicators and diverse data sources (RAN OSS, crowd-sourced data, transmission, transport, and core network elements).
• Identify root causes of underperforming KPIs and define corrective measures to improve network performance.
• Investigate systematic and mission-critical issues affecting service performance.
• Deliver detailed E2E performance reports with clear recommendations and action plans.
• Analyse end-to-end signalling flows (S1/X2/NG, GTP-C/U, SIP/IMS, PFCP).
• Monitor and optimise EPC/5GC KPIs, including registration/attach success, bearer/session setup, VoLTE/VoNR call quality, and handover success.
• Assess and troubleshoot backhaul performance issues related to latency, jitter, congestion, and packet loss.
• Collaborate with IP/Transport teams to evaluate routing, QoS, traffic engineering, synchronisation (PTP, SyncE), and network resiliency.
• Identify bottlenecks across microwave, fibre backhaul, and aggregation networks.
• Coordinate with Core Engineering teams on capacity planning, feature enablement, and software upgrades.
• Work cross-functionally with internal teams and third-party suppliers to agree and implement performance improvements.
• Apply automation and analytics techniques (SQL, Python, Tableau, Power BI) to identify trends, anomalies, and optimisation opportunities.

Technical Expertise

• Deep understanding of LTE and 5G NR technologies, including mobility, capacity, interference, coverage, and VoLTE/VoNR performance.
• Strong knowledge of EPC and 5GC core network architecture and cloud-native network functions.
• Expertise in IP/MPLS, Ethernet, QoS behaviours, and transport network performance.
• Solid understanding of 3GPP and ETSI standards.
• Knowledge of DTLS/SRTP protocols.
• Strong troubleshooting capability using Wireshark and protocol analysers for 4G/5G networks.
• Good knowledge of LTE parameters and timers.
• Familiarity with test tools and devices such as Accuver and other industry-standard performance tools.

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