代码分发协议中的自适应机制研究

Adaptive Mechanisms of Code Dissemination Protocol

代码分发技术是对无线传感器网络进行后期软件维护的关键技术,针对其易受干扰的特点,提出基于喷泉码的代码分发协议自适应机制,通过理论分析与仿真得到给定丢包率下使数据通信量最小的最佳冗余长度;根据实时估计的链路质量分别采用动态调整冗余分组数量和更换数据信道的方法减少总通信量,降低时延。实验结果表明,与固定冗余长度的代码分发协议相比,当丢包率小于0.1时,具有动态冗余长度机制的代码分发协议DRD可以减少约20.45%的通信量以及37.39%的分发时间;当丢包率介于0.1~0.25之间时,结合多信道与动态冗余长度机制的分发协议DRD&MCN可以减少约53.08%的通信量以及64.05%的分发时间。所提方法可使通信量与分发时间显著减少,提高了分发效率,有利于延长无线传感器网络的生存时间。

Code distribution technology is a key technology for later software maintenance of wireless sensor networks.In response to its sus⁃ceptibility to interference,a fountain code based code distribution protocol adaptive mechanism is proposed.Theoretical analysis and simula⁃tion are conducted to obtain the optimal redundant length that minimizes data traffic under a given packet loss rate;Based on the real-time es⁃timated link quality,dynamic adjustment of the number of redundant packets and replacement of data channels are used to reduce total com⁃munication volume and latency.The experimental results show that compared with fixed redundancy length code distribution protocols,DRD with dynamic redundancy length mechanism can reduce communication traffic by about 20.45%and distribution time by 37.39%when the packet loss rate is less than 0.1;When the packet loss rate is between 0.1 and 0.25,the distribution protocol DRD&MCN combining multi-channel and dynamic redundancy length mechanism can reduce approximately 53.08%of communication traffic and 64.05%of distribution time.The proposed method can significantly reduce communication volume and distribution time,improve distribution efficiency,and is bene⁃ficial for extending the survival time of wireless sensor networks.