无线网络数据帧新型传输策略及仿真

该文针对IEEE802．11无线Adhoe网络提出了一种新型的帧传输策略。IEEE802．11无线网络标准支持分布式协调功能(DCF)，即带冲突避免的载波监听多点接入(CSMA／CA)，在数据传输过程中使用“请求发送-确认发送-数据-接收确认(RTS-CTS-DATA-ACK)”模式。但是当数据帧长度较短时，很多带宽被浪费在信道竞争上，而且降低了信道传输成功率，减少了网络吞吐量。因此，根据每个帧携带的延时(Duration)值，调整站点的网络分配向量(NAV)，以此来动态调整数据帧的长度，从而增大网络传输的成功率，提高网络的吞吐量，减小整个网络的传送时延。将这种数据单元长度动态调整的帧传输策略简记为DTUL。

A New Method of Data Frame Transmission in Wireless Network and Simulation

In this paper, we propose a new method of the MAC protocol for IEEE 80 2.11 wireless Ad hoc network. The fundamental access method of the IEEE 802.11 M AC is a DCF known as carrier sense multiple access with collision avoidance, whi ch supports data transmissions using the RTS-CTS-DATA-ACK method. Although the R TS/CTS mechanism reduces the probability of collisions of data packets, much ban dwidth is wasted with the contention when the mean data length is short. What's more, the success radio of transmission and the throughput are also reduced. So we use the method of Dynamic Tuning of the Data Unit Length (DTUL) according to the NAV adjusted by the Duration/ID field in the frame, then the success ratio o f transmission and the throughput are improved, and at the same time the delay o f the whole network is reduced.