Simulation is a powerful tool for development of wireless networks. One key drawback of simulation-based studies for wireless networking is the need to use a radio propagation model. In this paper, we propose trace-based simulation for 6TiSCH (IPv6 over the TSCH mode of IEEE802.15.4e). We make the 6TiSCH Simula-tor run against connectivity traces collected in a real-world deployment. Our evaluation shows the trace-based simulation can yield almost the same results as experiments, with 1,200 times faster speed in execution time.