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代码分发一直是无线传感器网络研究的热点问题.目前的研究工作主要集中在同构场景下的代码分发,广播是这些研究工作中最常用的手段.而对于异构场景下的代码分发问题,研究工作则相对较少,传统的基于广播的方法很难直接适用.文中针对异构网络下的代码分发问题,把该问题归约为最小非叶节点MNN(minimum nonleaf nodes)Steiner树问题,并设计了一种基于多播的代码分发协议HSR(heterogeneous sensor networks scalable reprogramming protocol).该协议利用组件化的思想,为不同类型节点(或代码模块)建立了多棵最优代码分发多播树.并证明了在解决MNN问题时,HSR达到了理论最优近似率ln|R|(R为目标节点数),有效的降低了异构网络下代码分发过程中的通信开销和能耗.在此基础上,文中还设计了两种压缩编码机制:特殊路由日志机制SRL(special routinglog)和跳步受限的局部广播机制HLB(hops-restricted local broadcast),使得多播树的信息可以被无损压缩,增强了HSR协议的可扩展性.在实时性方面,提出了基于多播树的3阶段流水线调度方法,有效缓解了隐藏终端和干扰问题.仿真结果证明了协议的正确性和有效性.
Code distribution has always been a hot issue in the research of wireless sensor network.Currently, the research work mainly focuses on the distribution of code in the isomorphic scene, and broadcasting is the most commonly used method in these research work.For the problem of code distribution in heterogeneous scenes, The work is relatively less, and the traditional broadcast-based method is hard to apply directly. In this paper, the problem of code distribution in heterogeneous networks is reduced to the minimum nonleaf nodes (MNN) Steiner tree problem and designed A heterogeneous sensor networks scalable reprogramming protocol (HSR) is proposed based on Multicast. This protocol uses the idea of componentization to establish multiple optimal multicast code distribution trees for different types of nodes (or code modules). It is proved that the HSR achieves the theoretically optimal approximation ln | R | (R is the number of target nodes) in the solution of MNN, which effectively reduces the communication overhead and energy consumption in the process of code distribution in heterogeneous networks. On the other hand, two kinds of compression coding schemes are also designed: special routinglog (SRL) and hops-restricting d local broadcast) so that the multicast tree information can be losslessly compressed, which enhances the scalability of the HSR protocol.In terms of real-time performance, a 3-stage pipeline scheduling method based on multicast tree is proposed, which effectively alleviates the hidden terminal and interference The simulation results prove the validity and validity of the protocol.