According to an embodiment, a wireless communication device performs time-division communication and includes a storage and one or more processors. The storage is configured to store transmission data to be sent in a first period of time. The one or more processors are configured to perform a transmission process of sending the transmission data in a first frame at start of a plurality of frames included in the first period of time, or perform a transmission process of sending a pieces of divided the transmission data in a plurality of successive frames beginning from the first frame and included in the first period of time. After the transmission process, the wireless communication device switches to sleep mode in one or more frames of the first period of time.