Disclosed are methods, devices and systems for generating accurate timestamps for wireless communications signals that can be used to correct the clocks of base stations for wireless communications systems. A radio signal timestamping unit (RSTU) receives a wireless signal including timing information broadcast by a base station. The RSTU includes a local clock that is in communication with a high-precision time source and provides high-accuracy timing information to one or more base stations to maintain accurate clock synchronization among the plurality of base stations. The timing synchronization information can be determined at least in part based on the propagation delay of the wireless signals received at the RSTU.