ReOrbit is looking for a Payload Software Engineer to develop the software that powers our regenerative on-board 5G Non-Terrestrial Network (NTN) payload.
As our Payload Software Engineer, you will work at the intersection of 5G RAN software and spacecraft avionics, developing and integrating the gNB protocol stack that enables direct-to-device connectivity from Low Earth Orbit.You will play a key role in ReOrbit's OrbitCloud regenerative on-board payload for our NTN Direct-to-Device programme, supporting 5G services including VoNR and NB-IoT connectivity to unmodified handsets over an S-band service link.
It's an exciting chance to join a dynamic start-up, with the prospect to make a real impact, to reach our goal of pushing the boundaries of space data transfer.
Responsibilities
Design, implement and integrate the gNB Layer 2 protocol stack, including MAC, RLC, PDCP and SDAP, for a regenerative on-board 5G NTN payload.
Develop and adapt Layer 3 functionality, including RRC and NGAP/N2 signalling, for Low Earth Orbit operation.




Implement and integrate relevant 3GPP Release 17 and Release 18 NTN features, including timing advance, HARQ adaptation, feeder-link switchover and mobility procedures.
Port, optimise and harden the L2/L3 stack for embedded multicore Arm platforms operating under strict power, memory and real-time constraints.
Integrate L2/L3 functionality with the PHY/DFE partition using FAPI, nFAPI or equivalent split interfaces.
Integrate the protocol stack with on-board core network functions supporting services such as VoNR and NB-IoT.
Define and execute unit, integration and conformance testing using protocol testers, UE emulators and Hardware-in-the-Loop setups.
Debug and troubleshoot complex protocol, integration and performance issues using protocol analysers, logs and live system data.
Support in-orbit validation and troubleshooting of deployed payload software and network functionality.
Contribute to make-versus-buy decisions and technical eval

📌 Payload Software Engineer (Bengaluru)
🏢 ReOrbit
📍 Bengaluru