Senior Lead / Principal Architect – 4G/5G L2 Stack Software

Location: Delhi and Bangalore

Experience Level: 12+ years in 4G/5G L2 Software Development

Domain: Telecommunications, 3GPP LTE & 5G NR Layer 2 (MAC, RLC, PDCP), O-RAN, vRAN

Role Overview

We are seeking an experienced Senior Lead / Principal Architect – 4G/5G L2 Stack Software to design, architect, and implement high-performance Layer 2 protocol stacks (MAC, RLC, PDCP) for eNodeB (LTE) and gNodeB (5G NR) architectures. In this role, you will lead L2 software architecture across FDD and TDD modes, optimize MAC scheduling, drive platform integration with L1/L3/OAM, and manage large-scale product delivery, sustenance, and customer support across custom hardware, vRAN, and O-RAN deployments.

Roles & Responsibilities

- Architecture & Systems Engineering: Lead systems engineering, design, coding, debugging, and execution of 4G/5G L2 stack features across FDD and TDD modes with a focus on system-level scalability.

- Protocol Stack Development: Direct and review PDCP, RLC, and MAC layer development across diverse target platforms.

- Integration & Interoperability: Oversee L2 integration with physical layer (L1), control plane/user plane (L3), and OAM subsystems. Ensure robust interoperability across multi-vendor UE/chipset/Core Network environments.

- Team Mentorship & Leadership: Mentor high-performance engineering teams towards technical and delivery excellence.

- Program Delivery: Drive end-to-end delivery of large-scale 4G/5G L2 software programs, maintenance, and field support across varied base station form factors (O-RAN, vRAN, and custom eNB/gNB platforms).

- Executive Stakeholder Communication: Interface directly with internal leadership and external customer stakeholders to align on architecture, roadmap, and delivery goals.

Required Technical Expertise & Skill Sets1.



MAC Scheduling & Protocol Stack Core

- MAC Scheduling Algorithms: In-depth expertise in designing, developing, optimizing, and debugging eNodeB and gNodeB MAC schedulers.

- L2 Protocols (MAC / RLC / PDCP): Proven design and implementation expertise in segmentation/reassembly, ARQ/HARQ retransmissions, flow control, packet splitting/duplication, ciphering/integrity interaction, and QoS enforcement.

- TDD / FDD Timing Mechanics: Deep understanding of duplexing dynamics (TDD vs. FDD timing) on duplex-driven HARQ, scheduler timing, uplink grant strategies, DRX interactions, Buffer Status Reporting (BSR), and Logical Channel Prioritization (LCP).

- Performance Tuning: Performance optimization for ultra-low latency, throughput maximization, fairness, power-saving/DRX behavior, and QoS flow-to-radio bearer mapping.

- Interface & Architecture Split: Robust grasp of L2 interfaces with L1 and L3 protocols, alongside 3GPP RAN split options (e.g., Higher-Layer Split / Lower-Layer Split).

2. Software Architecture, Acceleration & Infrastructure

- Programming & Debugging: Advanced skills in C, C++, Python, state machine design, memory pooling, error handling, protocol decoding, and ASN.1 workflows.

- Hardware Offload & Acceleration: Knowledge of FPGA/SoC-based radio acceleration, SmartNIC/DPU-assisted data paths, DPDK, Hugepages, and SR-IOV.

- Virtualization & Platform Tuning: Linux system performance tuning for virtualized Distributed Unit (vDU)



and Centralized Unit (vCU) deployments on x86 and ARM architectures.

3. Log Analysis, KPI Optimization & Tools

- Log & Trace Analysis: Expertise in root-cause analysis of KPI drops using L2 traces, PCAPs, timing logs, RF test outputs, and protocol decodes.

- Log Diagnostics: Hands-on experience with system log analysis and UE trace tools like QCAT.

- Network Testing Equipment: High proficiency with test tools and traffic emulators including Viavi, IxLoad Wireless, IxNetwork, Spirent Landslide, and Wireshark.

4. 3GPP Wireless Standards Compliance3GPP LTE / E-UTRA Specifications:

- 36.300: Overall description (Stage 2)

- 36.314: Layer 2 - Measurements

- 36.321: Medium Access Control (MAC) protocol specification

- 36.322: Radio Link Control (RLC) protocol specification

- 36.323: Packet Data Convergence Protocol (PDCP) specification

- 36.401: E-UTRAN Architecture description

3GPP 5G NR Specifications:

- 38.300: NR and NG-RAN Overall description (Stage 2)

- 38.314: Layer 2 measurements

- 38.321: Medium Access Control (MAC) protocol specification

- 38.322: Radio Link Control (RLC) protocol specification

- 38.323: Packet Data Convergence Protocol (PDCP) specification

- 38.391: Ambient IoT Medium Access Control (MAC) protocol

- 38.401: NG-RAN Architecture description

- 38.410: NG-RAN NG general aspects and principles

Qualifications & Experience

- Experience: Minimum of 12 years of core 4G/5G L2 stack software development experience.

- Program Leadership: Demonstrated track record of leading delivery teams across multi-vendor L2 development and deployment programs.

- Education: Bachelor’s or Master’s degree in Computer Science, Telecommunications, Electronics & Communication Engineering, or equivalent.

📌 4G/5GStack Software - Senior Lead / Principal Architect (Bengaluru)
🏢 Neev
📍 Bengaluru