Improved cycle time synchronization method for isochronous data transfer on Wireless 1394 network

This paper presents the cycle time synchronization to transmit isochronous multimedia data by real time in wireless 1394 network. Wireless 1394 should synchronize the cycle time of a coordinator and those of slaves. In wireless 1394 system, the cycle time of a coordinator is transferred via beacons to slaves periodically. Beacons include cycle time information of a coordinator. This paper proposes a new cycle time synchronization method requiring only one beacon, not consecutive beacons in wireless 1394 network. In a conventional system, all slaves need to receive at least two consecutive beacons from the coordinator. However, it was hard to receive two consecutive beacons every time due to the noise in a wireless channel. Whenever all slaves receive a beacon, they save their beacon number and cycle time in the registers. They can get the time drift from the saved cycle time information of a previous beacon and the cycle time information of a current beacon. As experimental results, the proposed cycle time synchronization scheme achieves 82% performance improvement over the conventional cycle time synchronization method. This will contribute to transfer isochronous multimedia data using a UWB wireless channel. It successfully transfers this stream to the HDTV using two different wireless 1394 systems.