Job Description: Principal / Lead Wireless Systems Engineer (4G/5G Layer 2)Position Overview
We are seeking a highly experienced, technical leader with over
12 years of hands-on L2 software development experience to drive the design, architecture, and delivery of our 4G/5G Layer 2 protocol stack programs. In this role, you will lead the end-to-end development of high-performance basestation software (eNodeB/gNodeB) across various architectures, including traditional, vRAN, and O-RAN deployments. You will serve as a subject matter expert, mentoring high-performance teams, and interfacing with senior internal and external stakeholders.
Core Roles & Responsibilities
- Architecture & Systems Engineering: Lead the system engineering, high-level design, architecture, coding, debugging, and implementation of 4G/5G Layer 2 stacks for both FDD and TDD modes, ensuring feature scalability from a broad system perspective.
- Technical Leadership & Mentorship: Review the work of and mentor high-performance L2 engineering teams toward delivery excellence, focusing on PDCP/RLC/MAC development, OAM integrations, and critical interfaces with Layer 1 (PHY) and Layer 3.
- Program & Product Delivery: Drive large-scale 4G/5G L2 product development, product sustenance, and customer support programs across multiple eNodeB/gNodeB product variants.
- Stakeholder Communication: Act as the primary technical point of contact, effectively communicating complex technical strategies and project statuses to senior-level internal and external stakeholders.
Required Technical Skillset & Expertise1. 3GPP Wireless Standards Compliance
Deep technical familiarity and implementation-level understanding of the following 3GPP specifications:
- 4G (LTE): 36.300 (Overall Stage 2), 36.314 (L2 Measurements), 36.321 (MAC), 36.322 (RLC), 36.323 (PDCP), and 36.401 (E-UTRAN Architecture).
- 5G (NR): 38.300 (Overall Stage 2), 38.314 (L2 Measurements), 38.321 (MAC), 38.322 (RLC), 38.323 (PDCP), 38.391 (Ambient IoT MAC), 38.401 (NG-RAN Architecture), and 38.410 (NG General Aspects/Principles).
- Layer 2 Stack Architecture & Optimization
- MAC Scheduling: Advanced expertise in the design, development, optimization, and debugging of MAC scheduling algorithms for both eNB and gNB.
- Protocol Layer Deep-Dive: Proficiency in design and implementation across MAC, RLC, and PDCP layers—specifically covering segmentation/reassembly, retransmissions, flow control, packet splitting/duplication, ciphering/integrity interaction points, and QoS.
- Duplexing & Timing Operations: Strong grasp of L2 implications for TDD vs. FDD timing, including duplex-driven HARQ, scheduler timing, uplink grant strategies, DRX interactions, buffer status behavior, and logical channel prioritization.
- Performance Tuning: Proven track record of optimizing for latency, retransmission efficiency, throughput, fairness, DRX/power-saving behaviors, and QoS flow-to-radio bearer mapping.
- Interfaces & Split Architectures: Solid understanding of L2 interfaces with L1 and L3, alongside comprehensive knowledge of 3GPP RAN split architectural options.
- Software Engineering & Low-Level Platforms
- Programming Languages: Expert-level C, C++, and Python programming skills.
- Software Design: Mastery of memory pooling, state machine design, robust error handling, protocol decode workflows (ASN.1), and traceability.
- Hardware Acceleration & Virtualization: Understanding of FPGA/SoC-based radio acceleration, SmartNIC/DPU-assisted data paths, and DPDK/hugepages/SR-IOV.
- Infrastructure Deployment: Experience with Linux performance tuning for virtualized DU/CU implementations deployed on x86/ARM servers.
- Testing, Log Analysis & Diagnostics
- Interoperability Engineering: Proven capability in driving robust interoperability engineering across highly diverse UE, chipset, core, and network-vendor combinations.
- KPI Diagnostics: Ability to diagnose KPI loss using L2 traces, PCAPs, timing logs, and RF test outputs.
- Specialized Tooling: Proficiency in using UE log tools like QCAT, and network testing/measurement equipment including Viavi, IxLoad Wireless, IxNetwork, Spirent Landslide, and Wireshark.
Experience Qualifications
- Minimum 12+ years of direct, hands-on 4G/5G L2 software development experience.
- Demonstrated years of experience successfully driving the delivery of large-scale 4G/5G L2 programs from concept to commercial deployment.
Skills: 4g,architecture,design,mac,wireless,software,rlc,3gpp
