A communication system is disclosed that is capable of reducing data delay in transmitted hierarchized data and selecting predetermined data from the transmitted hierarchized data for communication according to conditions of the receiving end. The communication system includes a signal transmitting device that hierarchizes data to be transmitted and transmits the hierarchized data, and a signal receiving device that receives the data from the transmitting device. The signal transmitting device includes a hierarchized data transmitting unit that hierarchizes the data to be transmitted into a number of layers and transmits the data layers. The signal receiving device includes a layer identifying unit that identifies the data layers transmitted from the signal transmitting device, and a hierarchized data receiving unit that selects the identified data layers according to at least one of receiving capability and a propagating environment of the signal receiving device, and receives the selected data layers.