A method of exchanging a round trip time between a transmitting device and a receiving device in a wireless network comprises receiving an echo request command from an audio video control (AVC) layer to a medium access control (MAC) layer, the echo request command including a first identifier for identifying the transmitting device, a second identifier for identifying the receiving device, and a third identifier; transferring a MAC message from the MAC layer to a physical layer, the MAC message including a message preamble, a message type, and the echo request command; transmitting a first physical layer data unit to the receiving device, the first physical layer data unit including at least one header, the MAC message, and audio/video (A/V) data; and receiving a second physical layer data unit from the receiving device, the second physical layer data unit including an echo report command in response to the echo request command, the echo report command including the third identifier.