Principal Solutions Architect – Core & Signaling

About Skylo

Skylo is helping redefine how the world stays connected. At Skylo, our mission is to extend reliable connectivity to people, vehicles, and devices wherever they operate, even in the most remote and hard-to-reach places.

Skylo is a global connectivity company serving customers and partners worldwide. We enable satellite-based connectivity for everyday devices, helping smartphones, vehicles, and machines stay connected beyond traditional cellular coverage. Today, Skylo’s services are live on millions of devices across five continents, supporting use cases across consumer devices, automotive, and industrial sectors.

This role is located in North America following a hybrid working arrangement, spending 1–3 days per week based on the role and team needs.

Skylo is looking for a Principal-level Technical Subject Matter Expert (SME) to own the end-to-end technical integrity of our Core and Signaling architecture. This is not a project management role; it is a “boots-on-the-ground” technical leadership position. You will be the ultimate authority on 3

GPP 4G/5G signaling, responsible for designing the complex call flows that bridge Satellite (NTN) and Terrestrial networks. You will lead the “deep-room” technical sessions with MNO architects and build the definitive technical repository for Skylo’s core capabilities

• Signaling Master:
  Own the design and validation of end-to-end call flows (Attach, PDN Connectivity, Handover, SMSC timers, SMS over NAS) specifically for NB-IoT over NTN.

• 3
  
  GPP Interface Mastery:
  Act as the lead for all protocol-level discussions involving S1, NAS, S6a (Diameter).

• Air Interface Bridge:
  Deep-dive into the interaction between the UE and the eNB/gNB, ensuring the Core Network correctly handles NTN-specific constraints like high propagation delay and Doppler shifts.

• The “Black Belt” Interfacer:
  Lead high-stakes technical workshops with MNO (Mobile Network Operator) Core Network teams. You are the person they call when the conversation moves from “What does it do?” to “Show me the packet trace.”
• System Integration:
  Design the complex roaming and interconnect architectures (S8, T7 interfaces) required to integrate Skylo’s NTN Core with global MNO partners.

• Technical “Source of Truth”:
  Build and maintain the Skylo Technical Repository. This includes authoring:

• Interface Control Documents (ICDs) and High-Level Designs (HLDs).

• Detailed Call Flow Sequence Diagrams for every supported service.

• Troubleshooting guides for signaling “corner cases” unique to satellite environments.

• Understanding of GSMA Member gateway and should be comfortable with creating of IR.21 and updating the documentation and be part of technical working group at GSMA to represent Skylo

• Internal Training:
  Distill complex 3
  
  GPP and NTN concepts into training modules for the broader engineering and field teams.

• Billing Alignment:
  Partner with the Settlement Lead to ensure that the Charging Trigger Functions (CTF) in the 4G/5G Core are generating accurate data for CDR creation.

• 12 Years of Telecom Rigor:
  Extensive experience in 4G/5G Core Network architecture (EPC and 5GC). You should have spent years “in the logs” (Wireshark, QXDM) at a major vendor (Ericsson, Nokia, Huawei) or a Tier-1 MNO.
• Protocol Forensics:
  Ability to debug complex signaling issues at the packet level. You should be able to identify a missing Information Element (IE) in a NAS message that is causing a registration failure.
• NTN Awareness:
  While Sat Com experience is a plus, you must have the technical curiosity and foundational physics knowledge to understand how Long RTT (Round Trip Time) affects standard 3
  
  GPP timers (e.g., T3410, T3412).
• Documentation Specialist: A passion for clarity. You take pride in creating diagrams and documents that are technically flawless and easy to navigate

With employees working across three continents, Skylo is proud to be an equal opportunity employer dedicated…