The present invention provides a method and a controller to control not only cellular radio connections in a cell of a cellular communication system but also direct device-to-device communication links established between terminal devices within the cell. Particularly, the controller selects portion of the terminal devices to function as relay terminals for the other terminals to enable relayed communication links between the terminal devices and the base station through the relay terminals. The relay terminals link device-to-device connections to the cellular radio connections between the relay terminals and the base station.