NBIOT L2 Engineer

Key Responsibilities

• Design, implement, and debug Layer 2/3 control and data path features
• Maintain MAC scheduler behavior for UL/DL grant decisions and resource allocation
• Work on RLC and PDCP flows for segmentation, retransmission, reordering, and bearer management
• Implement and validate UE/CELL state transitions driven by RRC and S1AP/X2AP messages
• Troubleshoot protocol interoperability and real-world failure scenarios
• Optimize scheduler and bearer behavior for NB-IoT constraints such as coverage, latency, and power efficiency

Must-have skills

Preferred experience

Qualifications

• Must-have skills
• Strong understanding of 3GPP LTE/NB-IoT Layer 2 and Layer 3 protocols:MAC scheduling, HARQ, RACH, paging, logical channels, and UE state handlingRLC modes and retransmission behaviorPDCP sequence numbering, security, ROHC, and bearer managementRRC setup/reconfiguration/release and UE control proceduresS1AP/X2AP signaling and UE/cell context management
• Hands-on experience in C/C++ development for telecom or embedded networking stacks
• Familiarity with low-latency, real-time scheduling and event-driven protocol processing
• Experience with:Linux/Unix environmentsmultithreading and shared-memory designtimers, state machines, and protocol packet processingdebugging packet traces and protocol logs
• Understanding of LTE/NB-IoT bearer concepts:SRB/DRBlogical channels and transport channelsUE context, cell context, and RB reconfigurationconnection establishment, mobility, and release procedures
• Experience with NB-IoT or LTE eNodeB stack development
• Knowledge of 3GPP specs: MAC, RLC, PDCP, RRC, S1AP, X2AP
• Familiarity with ASN.1 / protocol encoders/decoders
• Experience with security/encryption functions used in PDCP
• Exposure to scheduler optimization, throughput/latency tuning, and interference handling
• Ability to work with vendor stacks and trace tools such as Wireshark, logs, and internal UE/eNB diagnostics
• Accessibility
• Mavenir is committed to working with and providing reasonable accommodation to individuals with physical and mental disabilities. If you require any assistance, please state in your application or contact your recruiter.
• Mavenir is an Equal Employment Opportunity (EEO) employer and welcomes qualified applicants from around the world, regardless of their ethnicity, gender, religion, nationality, age, disability, or other legally protected status.

Preferred Qualifications

• Preferred experience