A first base station receives, from a second base station, a request message indicating a small data transmission (SDT) procedure of a wireless device. The first base station sends, to the second base station, an indication that the first base station keeps a context of the wireless device. The first base station receives, from the wireless device via the second base station, uplink data associated with the SDT procedure. The first base station sends, to the second base station and based on completion of the SDT procedure, a radio resource control (RRC) release message for the wireless device.