With CSMA/CD two or more stations share a common transmission medium. To transmit a frame, a station must wait for an idle period on the medium when no other station is transmitting. It then transmits the frame by broadcasting it over the medium such that it is "heard" by all the other stations on the network. If another device tries to send data at the same time, a "collision" is said to occur. The transmitting station then intentionally transmits a "jam sequence" to ensure all stations are notified the frame transmission failed due to a collision. The station then remains silent for a random period of time before attempting to transmit again. This process is repeated until the frame is eventually transmitted successfully. CSMA/CD access is used by Ethernet (IEEE 802.3), HomePNA and wireless LANs (IEEE 802.11).