An Efficient Fragment Packet Transmission Scheme in Wireless Sensor Networks

초록

Data link layer framing in wireless sensor network usually faces a trade-off between large frame sizes for high channel utilization and small frame sizes for effective error recovery. In this paper, a novel design scheme is proposed, which describes a data link layer that resolves the dilemma by decoupling framing from error recovery. Meanwhile, it breaks the data packet into blocks, adds CRC to every block for error detection, and packages several such blocks into a frame. The receiver retransmits erroneous blocks only. Consequently, the FER become irrelevant to frame size. A frame can therefore be sufficiently large in great favor of high utilization of wireless channel. This scheme has been implemented as a new data link layer in TinyOS, and evaluated through real experiment in sensor motes. The result shows that it improves the throughput by at least 20% under typical wireless channel condition.