萬代 雅希

To improve success rate performance of data packet transmission without degrading throughput performance, we propose an efficient, Medium Access Control (MAC) protocol in wireless ad-hoc networks with heterogeneous power nodes. In the proposed protocol, a high-power node for-wards the Request-To-Send (RTS) packets and Clear-To-Send (CTS) packets from a low-power node. Therefore, the proposed protocol can reduce collisions that occur after connection establishment, regardless of the size of the transmission range. By computer simulations, we show that the proposed protocol can improve success rate performance of data packet transmission without degrading throughput performance compared with the IEEE 802.11 protocol.

We propose VBR video transmission scheme with isochronous and asynchronous transfer mode over Wireless 1394. In the proposed scheme, to decrease the idle bandwidth in the isochronous area, the video station which uses the isochronous transfer mode is assigned the bandwidth equivalent to the average rate of video stream. The video data over the average rate are transmitted in the asynchronous transfer mode, and the video stations have higher priority of transmitting right than the data stations in the asynchronous transfer mode. By using computer simulations, we show that the proposed scheme can improve the channel utilization performance and the waiting time performance, and we show that the proposed scheme is effective for VBR video transmission.