Federated Array Intelligent Link Server Architecture for Enhanced Synchronization (FAILSAFESTM)

Wilbur Myrick

Abstract:	Federated Array Intelligent Link Server Architecture for Enhanced Synchronization (FAILSAFES^TM) is an Open Time Server Cluster Architecture for both Internet-of-Things (IoT) RF ranging terrestrial links and Global Navigation Satellite System (GNSS) receiver array processing leveraging Wi-Fi/4G/5G MIMO Antennas. FAILSAFES^TM creates a Precision Time Protocol (PTP) grandmaster cluster architecture that can integrate both COTS GNSS receivers and Internet-of-Things (IoT) RF ranging technology to support resilient and redundant timing and positioning array solutions based on low Size, Weight, Power, and Cost (SWaP-C) RF Ranging links for operating in degraded or denied GNSS environments. This paper describes the IoT RF Ranging Fusion component of FAILSAFES^TM and discusses the underlying timing capabilities based on our PicoRanger^TM Array Technology (PRAT). PRAT provides an array of low-cost IoT RF ranging links between arrays allowing nodes that are part of FAILSAFES^TM to support navigation and timing distribution in degraded or denied GNSS environments. This paper will explore components of FAILSAFES^TM and discuss initial PRAT based fusion results with respect to frequency and time stability. Current navigation systems leverage the Global Navigation Satellite System (GNSS) for autonomous navigation. Layers of resiliency and redundancy are important for these systems to navigate in GNSS degraded or denied environments. ENSCO has been developing high-precision Radio Frequency (RF) wireless two-way time-frequency transfer (TWTFT) technology based on ENSCO’s patented Timing, Communications, and Ranging (TCR) technology for more than 15 years. This technology has demonstrated high-precision time dissemination and synchronization capability that simultaneously provides distance and speed measurements between ENSCO-developed Software Defined Radios (SDRs) that incorporate this TCR Technology. ENSCO is currently focused on low Size, Weight, Power, and Cost (SWAP-C) form factors targeting small uncrewed aircraft systems (sUAS) and micro air vehicles (MAVs) to support navigation and timing operation in degraded and denied GNSS environments. This miniaturized version of the TCR technology is known as the PicoRanger^TM Array Technology (PRAT). PRAT leverages Internet-of-Things (IoT) System-on-Chips (SoCs) to provide an array of low SWAP-C communication and timing links to communicate and share timing information between nodes that are part of the network. FAILSAFES^TM is a PTP grandmaster cluster architecture that leverages fusion algorithms to combine arrays of timing links between these nodes. Preliminary results from PRAT measurements are discussed in this paper to illustrate the feasibility of this fusion approach with respect to frequency and timing stability measurements. A natural extension to positioning and navigation can be made once timing stability measurements are collected so this paper mainly focuses on preliminary fusion results with respect to a resilient PTP grandmaster timing delivery capability. The current FAILSAFES^TM system is composed of Commercial-off-the-Shelf (COTS) components that are plug-andplay. FAILSAFES^TM system is composed of a 1) COTS computer functioning as a PTP Grandmaster, 2) Time Card, 3) PRAT, and 4) Synchronization Fusion Software. The architecture combines Meta’s Open Compute Project Timing Applications Project (OCP-TAP) Time Card with ENSCO’s PRAT. The current testing configuration is focused on having a single PicoRangerTM module on mobile platform so the synchronization fusion algorithm can combine an array of RF ranging measurements from PRAT at the ground node (there is a plan to extend a similar configuration to the mobile node). This paper focuses on preliminary frequency and timing error measurements of FAILSAFES^TM between the PRAT transceivers collecting data from indoors. The relative timing error measurements naturally extend to the complementary positioning services needed for mobile node positioning when GNSS is denied or degraded. Components of the FAILSAFES^TM prototype demonstration system used to explore fusion algorithms associated with PRAT will be discussed.
Published in:	Proceedings of the 38th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2025) September 8 - 12, 2025 Hilton Baltimore Inner Harbor Baltimore, Maryland
Pages:	2069 - 2073
Cite this article:	Myrick, Wilbur, "Federated Array Intelligent Link Server Architecture for Enhanced Synchronization (FAILSAFESTM)," Proceedings of the 38th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2025), Baltimore, Maryland, September 2025, pp. 2069-2073. https://doi.org/10.33012/2025.20250
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