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.