Network synchronization for distributed MANET

Mobile ad-hoc networks (MANET) are often characterized with rapidly changing topologies, presenting a constant challenge for time synchronization. This challenge holds especially true in tactical edge ground military networks, where topological instabilities are enhanced by hostile transmission environments. In the absence of GPS, time synchronization within the context of a tactical environment requires resilience and ease of deployment. Hardware requirements must be carefully controlled, while relying on distributed coordination techniques to avoid single points of failure. Current tactical ground networks are often deployed without high accuracy oscillators, but still require time synchronization on the order of 1us. Our work demonstrates a distributed synchronization approach with a resource efficient solution that handles these requirements. We introduce cross-layer ad-hoc network synchronization (CLANS), a low overhead time synchronization protocol designed for MANETs and enables coarse synchronization without relying on GPS data. CLANS leverages routing information, channel access schemes, and distributed scheduling protocols that typically exist in a MANET. This provides a resilient, distributed time synchronization solution with relaxed hardware requirements. Simulation results show that CLANS can achieve network synchronization within 1 us in lossy multi-hop networks with the presence of packet loss and measurement noise.