Decentralized PNT (Positioning, Navigation, and Timing) refers to systems where each device independently determines its own location, movement, and time using onboard sensors and local data, rather than relying on a single, centralized source like GPS. This approach enhances resilience against signal jamming, spoofing, or outages, as devices do not depend on external signals that could be disrupted or manipulated. Decentralized PNT is increasingly important for critical infrastructure, autonomous vehicles, and secure communications, providing robust and secure alternatives to traditional centralized navigation and timing systems.