Principal Engineer - Device Expert (Satellite to Cellular Networks)

AST SpaceMobile is building the first and only global cellular broadband network in space to operate directly with standard, unmodified mobile devices based on our extensive IP and patent portfolio and designed for both commercial and government applications.

Our engineers and space scientists are on a mission to eliminate the connectivity gaps faced by today's five billion mobile subscribers and finally bring broadband to the billions who remain unconnected.

Position Overview We are seeking a Principal Engineer - Device Expert with deep mastery of 3GPP standards (Rel-15 through Rel-18 and beyond) and proven experience in device, chipset, and OEM-level validation.

This individual will serve as the technical authority on devices for our satellite-to-cellular program, ensuring end-to-end compliance with 3GPP NTN adaptations while proactively challenging chipset vendors to drive architectural improvements when required.

This role demands both strategic vision and hands-on execution, bridging device-level validation with system integration, lab/field optimization, and feature delivery.

The Device Expert will play a critical role in ensuring devices are NTN-ready, operator-compliant, and performance-optimized for production-grade service.

Key Responsibilities * Serve as the principal authority on device behavior across 3GPP Rel-17/18 NTN features, including TA adjustment, HARQ, Doppler management, PRACH repetition, and UE delay handling.

* Lead device/OEM/chipset engagements; challenge architectural gaps and negotiate standards-compliant solutions.

* Drive compliance verification against Tier-1 operator requirements (e.g., 1.4 MHz/3 MHz carriers on Band 5/B12). * Lead IODT/FOA device testing and validation, including log-level debugging with industry-standard tools.

* Design and execute KPI-driven FOA test plans (RACH, RRC, throughput, latency, MOS, handovers across NTN/TN). * Contribute to lab integration, field acceptance, optimization, and L1-L4 operations for device interoperability.

* Map 3GPP traces to real-world execution, ensuring device compliance and readiness for commercial launch.

* Partner with satellite payload SMEs, RAN/Core engineering, and gateways to align RF/device interface performance.

* Anticipate future device requirements to scale the organization's global roadmap, beyond initial FOA/NTN phases.

Qualifications Education Bachelor's or master's degree in electrical engineering, Telecommunications, Computer Engineering, or related field.

Experience A minimum of 15-20 years in telecom device engineering, device validation, or chipset-level R&D.

Preferred Qualifications * Proven delivery of NTN-compliant device validation with Tier-1 operators.

* Deep fluency with Tier-1 operator NTN roadmaps, compliance requirements, and device program initiatives.

* Experience designing and executing multi-phase validation architectures (Lab FOA Optimization Ops). * Ability to lead small device-focused teams across lab and field domains.

* Strong relationships within chipset/OEM ecosystems and MNO device certification groups.

* Demonstrated expertise in RAN-to-device protocols, including synchronization (timing advance), error correction (HARQ), mobility compensation (Doppler), and procedures for paging and seamless handovers.

* Proven ability to drive architecture-level enhancements with chipset and OEM partners, influencing long-term product roadmaps.

* Familiarity with Tier-1 mobile operator certification and compliance processes, including device readiness for commercial deployment.

Soft Skills * Ability to challenge vendors constructively while driving consensus.

* Strategic mindset with execution-first ownership.

* Excellent documentation and communication skills at both engineering and executive levels.

* Comfort operating in high-ambiguity, high-stakes telecom launch environments.

Technology Stack * Diagnostic and validation tools: QXDM, TEMS, Accuver, Shannon, Actix, Wireshark, Keysight, Spirent * Protocol analysis and log tracing across L1-L4 layers * Familiarity with 3GPP standards, especially NTN adaptations for 4G/5G NR Physical Requirements * Ability to work in a standard office environment and use a computer for extended periods.

* Willingness to travel for field testing and device validation as needed.

This job description may not be inclusive to the duties and responsibilities listed.

Additional tasks may be assigned to the employee from time to time or the scope of the job may change as needed by business demands.

AST SpaceMobile is an Equal Opportunity, at will Employer; employment is governed on the basis of merit, competence and qualifications and will not be influenced in any manner by race, color, religion, gender, national origin/ethnicity, veteran status, disability status, age, sexual orientation, gender identity, marital status, mental or physical disability or any other legally protected status.