Poster abstract: Direct multi-hop time synchronization with constructive interference

Multi-hop time synchronization in wireless sensor networks (WSNs) is often time-consuming and error-prone due to random time-stamp delays for MAC layer access and unstable clocks of intermediate nodes. Constructive interference (CI), a recently discovered physical layer phenomenon, allows multiple nodes transmit and forward an identical packet simultaneously. By leveraging CI, we propose direct multihop (DMH) time synchronization by directly utilizing the time-stamps from the sink node instead of intermediate n-odes, which avoids the error caused by the unstable clock of intermediate nodes. DMH doesn't need decode the flooding time synchronization beacons. Moreover, DMH explores the linear regression technique in CI based time synchronization to counterbalance the clock drifts due to clock skews.