Software Engineer, OAI UE Stack

Job Description

As Software Engineer for the OAI UE Stack, your mandate is to become CloudlyIO's internal expert on the OAI UE: how it works, where its boundaries are, how it can be customized, and how it behaves in the kinds of production network environments our customers operate. This is a deep-build role. You will spend significant time reading, running, breaking, and rebuilding OAI UE code before you are customizing it for customer contexts.

The output of this work feeds directly into CloudlyNet's value proposition. Customers who deploy CloudlyNet to optimize their RAN need to trust that CloudlyIO understands the full network, from the base station through the air interface to the device. This role is how we earn that credibility on the UE side.

ABOUT CLOUDLYNET AND THIS ROLE'S PLACE IN IT
CloudlyNet is our RAN optimization platform for telecom operators and enterprise networks. It uses a Bayesian Digital Twin with real UE data to reduce energy waste, balance network load, improve mobility, and close coverage gaps across 4G and 5G deployments.To make CloudlyNet work credibly and completely for production customers, we need deep internal expertise in the open-source protocol stacks that underpin modern radio networks. This role focuses entirely on the user equipment side of that stack: OpenAirInterface (OAI) and its fully open-source 5G NR UE implementation.

ABOUT OPENAIRINTERFACE UE
The OAI UE is a fully open-source User Equipment stack maintained by the OpenAirInterface Software Alliance. It supports 5G NR with FR1 across all bandwidths, FR2 at 100 MHz, up to four downlink and two uplink layers, 256-QAM modulation, and throughput up to 190 Mbps downlink and 120 Mbps uplink in single-layer configuration. It interoperates with the OAI gNB and third-party commercial base stations, runs on both x86 and ARM architectures, and supports 5G Sidelink, Non-Terrestrial Networks under 3GPP Release 17, and simulation modes including rfsim, ulsim, dlsim, and vrtsim for full end-to-end testing without RF hardware.The OAI codebase is the starting point. The work in this role is to go far beyond it: understanding it deeply, customizing it for production environments, and building the expertise that makes CloudlyIO a credible technical partner for customers who are running or testing real 5G UE behavior.


Job Requirement

  • Build deep working expertise in the OAI UE codebase, including the full 5G NR UE protocol stack from PHY through RRC and NAS, on both the SA and NSA paths
  • Run, test, and characterize OAI UE behavior across simulation modes including rfsim, ulsim, dlsim, and vrtsim, and document findings in a way that is useful for the broader CloudlyNet team
  • Develop and maintain customizations to the OAI UE stack for production customer contexts: modifying PHY/MAC parameters, adjusting scheduler behavior, adapting measurement reporting, and configuring UE capabilities for specific frequency bands, numerologies, and deployment scenarios
  • Integrate OAI UE testbed setups with CloudlyNet's Bayesian Digital Twin, providing ground-truth UE behavior data that improves model fidelity and optimization accuracy
  • Build and maintain test environments for validating CloudlyNet optimization outcomes from the UE perspective, including throughput, mobility, SINR, and handover performance measurements
  • Track and contribute to the OAI UE roadmap and community, monitoring new feature releases, known issues, and community directions that are relevant to CloudlyIO's production use cases
  • Document OAI UE customizations, deployment guides, and integration notes clearly enough that solution engineers and ML engineers can use them in customer engagements
  • Support solution engineers and ML engineers in customer conversations that require UE-side technical depth, including questions about measurement reporting, UE capability negotiation, and device-side behavior in optimization scenarios
YOU MAY BE A GOOD FIT IF YOU HAVE

  • 2 to 4 years of experience in telecommunications software engineering, wireless systems development, or open-source RAN stack work
  • Hands-on familiarity with the OAI codebase, or equivalent depth in another open-source 5G protocol stack such as srsRAN 4G
  • Strong proficiency in C and C++, which are the primary languages of the OAI UE stack
  • Working knowledge of 5G NR protocol layers: PHY, MAC, RLC, PDCP, RRC, and NAS, and how they interact in a real UE implementation
  • Understanding of 5G NR air interface fundamentals including numerologies, frame structure, beamforming basics, and HARQ
  • Comfort working in Linux-based development environments and running RF simulations without physical hardware
  • Genuine interest in open-source telecom software and the technical depth required to customize it for production use rather than just run it as-is

PREFERRED QUALIFICATIONS
  • Prior experience contributing to or customizing the OAI codebase, specifically on the UE side
  • Familiarity with 5G SA call flows, RRC state machines, and NAS signaling
  • Experience with RF hardware such as USRP or other SDR platforms for real-world OAI UE testing
  • Knowledge of 5G Sidelink or Non-Terrestrial Network features under 3GPP Release 17 or later
  • Familiarity with O-RAN Alliance specifications and how open-source UE stacks interoperate with O-RAN-compliant base stations
  • Bachelor's or Master's degree in Telecommunications Engineering, Electrical Engineering, Computer Science, or a related field

COMPENSATION & BENEFITS
  • Salary: Competitive base, negotiable based on experience
  • Performance-based commission structure: your earnings scale directly with your results
  • Two annual festive bonuses, each equivalent to half a month's salary
  • Two-day weekends, 10 days casual leave, 10 days sick leave, and 14 public holidays per CloudlyIO's global holiday calendar for Bangladesh
  • Fully subsidized lunch and evening snacks, plus tea and coffee throughout the day
  • Direct collaboration with US clients and teams, with real exposure to global enterprise AI deals from day one