Positioning determination of a communication device in a wireless communication network is supported by a positioning device receiving [230] tight synchronization signals from a master positioning cell; determining [232] therefrom a plurality of time differences between their actual and theoretical times of arrival; synchronizing [234] a positioning cell clock based on the received tight synchronization signals adjusted by the time differences; and emitting [236] to the communication device a positioning signal at a time determined by the synchronization. The positioning signal includes an identifier of the positioning cell, and it is transmitted so as not to interfere with positioning pilot signals transmitted by the wireless communication network. The positioning device may alternatively receive synchronization signals from another positioning cell instead of a master positioning cell.