This paper considers the time synchronization problem in wireless multihop networks. The objective is to design a protocol that synchronizes the network nodes with respect to one reference node. A set of sender nodes forming a connected dominating set is created to guide the synchronization process in a multihop environment. Each node estimates its clock offset and frequency error parameters to build an adjustment function that transforms its local time to that of the reference node. Our protocol estimates the clock offset and the frequency error on different time scales leading to significant gain in terms of synchronization accuracy. We give the theoretical bounds on the synchronization precision and show its performance through extensive simulations