 These measurements are gathered today during highly expensive drive tests  and will be reported in the near future by users equipments thanks to the 3GPP MDT feature ( still costly in terms of battery consumption and signaling overhead ). In both cases , predicting the coverage on a location where no measurements are available remains a key and challenging task.
<coherence>  These measurements are gathered today during highly expensive drive tests  and will be reported in the near future by users equipments thanks to the 3GPP MDT feature ( still costly in terms of battery consumption and signaling overhead ). In both cases , predicting the coverage on a location where no measurements are available remains a key and challenging task.
 These measurements are gathered today during highly expensive drive tests and will be reported in the near future by users equipments thanks to the 3GPP MDT feature ( still costly in terms of battery consumption and signaling overhead . Therefore , predicting the coverage on a location where no measurements are available remains a key and challenging task.