一种基于发送队列长度的自适应功率控制机制

An Adaptive Power Control Mechanism Based on Send Queue Length

无线多跳网络具有信道时变性强、拓扑动态变化等特点,需要简单高效的功率控制机制。发射功率影响数据发送速率,而基于发送队列长度的功率控制机制存在可行解。为此,结合无线多跳网络中间节点需要协助其他节点进行数据转发的特点,基于发送队列长度,提出一种功率控制机制。该机制考虑了中间节点转发时发送队列缓冲区溢出丢包的问题,通过扩展控制报文携带发射功率和可容忍噪声等信息动态调整功率,提高信道的空间复用率,优化网络的吞吐量和端到端时延。基于NS2的仿真结果表明,与POWMAC机制及ATPMAC机制相比,该机制的吞吐量提高20%~30%,端到端时延降低10%~20%。

Because of the characteristics of strong time variability channels and dynamic changed topology in wireless multi-hop network, power control mechanism should be simple and efficient. The theory proves that the transmit power affects the data send rate. There is a feasible solution to the power control mechanism based on the length of the send queue. According to the fact that intermediate nodes of wireless multi-hop network need help other nodes to carry out the data forwarding,based on the length of the send queue, this paper proposes a power control mechanism. The mechanism considers the problem of buffer overflow packet loss of send queue when intermediate nodes forward information, dynamicly adjusts power through extension of control message carrying transmit power,information of tolerant noise and so on, thus improves the reusability of space, optimizes the network throughput and the end-to-end delay. Simulation results on NS2 show that, compared with POWMAC mechanism and ATPMAC mechanism, the throughput of the proposed mechanism is higher by 20% ~ 30% , and the end-to-end delay is lower by 10%- 20% .