基于能量均衡的无线传感器网络组播路由协议

在无线传感器网络实际应用中,组播技术能够较好地满足网络对资源的要求,但由于能量等多方面的因素限制,使得为无线传感器网络设计一个有效的组播路由变得非常困难.针对无线传感器网络中节点的能量限制,提出一种基于能量均衡树的无线传感器网络组播路由(EBTMR)协议,该协议充分考虑到网络中节点的能耗因素和节点的剩余能量,通过对这2个因素的综合考虑,使得具有较多能量的节点担任组播节点来承担更多的传输任务,为数据流优化路由选择,平衡无线传感器网络中节点的能量消耗,以延长网络的生存时间,仿真结果证明了EBTMR是有效的.     

基于外层空间的无线传感器网络组播路由协议研究*

研究航天器部署在火星表面的无线传感器节点,首次提出了外层空间无线传感器网络(outer space wireless sensor network,OSWSN)的概念,指出该网络的节点以自组织方式组网。基于已有的地面无线传感器网络经典组播路由协议,结合无线自组织网络组播协议建树思想,设计应用于外层空间无线传感器网络的OSWSNMP（OSWSN multicast protocol）。与已有的MAODV组播路由协议以及应用于地面无线传感器网络的EMRS组播路由协议进行比较,在NS2上搭建OSWSNMP仿真环     

无线传感器网络路由协议研究

路由协议提供了从源节点到目的节点的优化路径,在无线传感器网络体系结构中至关重要。本文首先针对无线传感器网络的特点,提出了在路由协议的设计过程中需要重点考虑的性能指标,然后分析了一些当前典型的路由协议,并从拓扑结构、通信模式、路由开销等方面对这些协议进行了比较,最后结合该领域当前的研究现状指出了未来的研究趋势。     

无线传感器网络能耗均衡路由技术研究

无线传感器网络的路由技术提供了从源节点到目的节点的优化路径,因关系到网络的能耗和生命周期而成为当今的技术研究热点。文章介绍了无线传感器网络特点及其经典的路由协议,简要分析了这些路由技术的特点,并针对这些技术存在的不足提出了一种新的兼顾无线传感器网络局部和全局的分类多路径能耗均衡路由方法,阐述了该方法的设计思路。     

基于虚拟Steiner树的无线传感器网络组播随机路由协议研究

针对基于树的组播路由协议中组播树鲁棒性不好,扩展能力差的特点,又结合无线传感器网络自身能量、计算、存储能力有限的特点,提出了基于虚拟Steiner树的组播随机路由协议VMRRP(Virtual-steiner-tree based Multicast Random Routing Protocol)。该协议的随机路由思想,使得组播树中源节点到各个组成员节点的路径是动态变化的,与GMP(Geographic Multicast Routing)协议相比,增加了组播树的鲁棒性,也均衡了网络能量,增加了网络生命周期,并通过NS-2仿真试验得到了验证。     

一种改进的WSN源位置隐私保护路由算法

在无线传感器网络通信中,针对已有幻象路由协议可能因失效路径而降低源节点安全时间的问题,提出了一种基于最短距离路由的无线传感器网络源节点位置隐私保护路由算法.该路由算法包括初始化过程、改进的源节点幻象路由策略和避开源节点可视区的最短距离路由策略.理论分析和实验结果表明,与已有的幻象路由协议相比,该路由算法生成的幻象节点能较好地远离源节点,并且提高了源节点的安全时间,可以较好地保护源节点位置的隐私安全.     

基于带状区域路由的无线传感器网络QoS协议

提出了一种基于带状区域路由的无线传感器网络QoS协议。根据网络传输路径的能耗模型分析,将路由的转发节点控制在以源节点与Sink节点连线的带状区域,有效降低了路径上的传输能耗。另外,在改进型QoS协议中,转发节点根据当前QoS约束动态重新建立新的带状区域宽度,使传输路径最大程度拟合源节点和Sink节点的连线,达到路径传输能耗最优。仿真实验表明,无线传感器网络QoS协议在满足网络QoS约束下,节省了网络能耗,延长了网络生存时间。     

基于预测时延的无线mesh网络组播路由算法

通过对无线mesh网络的特性分析及其对路由的影响,提出一种基于预测时延的路由选择的组播路由算法,该算法通过选择从源节点到目的节点传输时延最小的路径,通过路径合并,形成组播路由树。这种路由算法具有低时延QoS保障能力,并具有局部修复能力。基于NS2对算法进行仿真,结果证明了算法的有效性。     

无线传感器网络分层路由协议的研究

无线传感器网络作为一种新兴的信息获取技术,是当前的研究热点。由于无线传感器网络节点能量有限,因此对其路由协议的研究成为重中之重。对近年来无线传感器网络路由协议进行归纳和分析,并基于分层路由协议提出一种均衡能量消耗的改进方案。首先,使用K-means聚类算法形成分簇,分簇形成后综合考虑节点能量和到簇中心的距离两个因素选出簇头。其次,使用多跳路由的方式进行通信,根据簇头到汇聚节点的距离形成最佳路径。     

基于分簇的无线传感器网络安全组播路由协议

针对无线传感器网络节点能量、计算和带宽有限的特点．提出一种适用于无线传感器网络的基于分簇的安全组播路由协议（CSMR）。该协议采用了HiM-TORA的树形组播寻路机制，并引入了TESLA密钥链与时间同步等安全机制，能够自动且安全地构建覆盖所有组播组成员的组播树，且在路由建立的阶段就能对成员的身份和相关的信息进行认证，有效的防止了对组播路由的各种攻击。同时分析了该协议的安全性与有效性。     

Scalable Base-Station Model-Based Multicast in Wireless Sensor Networks

Multicast is essential for wireless sensor network (WSN) applications. Existing multicast protocols in WSNs are often designed in a P2P pattern, assuming small number of destination nodes and frequent changes in network topologies. In order to truly adopt multicast in WSNs, we propose a base-station model-based multicast, SenCast, to meet the general requirements of applications. SenCast is scalable and energy-effcient for large group communications in WSNs. Theoretical analysis shows that SenCast is able to approximate the Minimum Nonleaf Nodes (MNN) problem to a ratio of ln |R| (R is the set of all destinations), the best known lowest bound. We evaluate our design through comprehensive simulations and prototype implementations on Mica2 motes. Experimental results demonstrate that SenCast outperforms previous multicast protocols including the most recent work uCast.     

异构无线传感器网络中一种可扩展的代码分发技术

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.     

Resource deadlocks and performance of wormhole multicast routingalgorithms

We show that deadlocks due to dependencies on consumption channels are a fundamental problem in wormhole multicast routing. This type of resource deadlocks has not been addressed in many previously proposed wormhole multicast algorithms. We also show that deadlocks on consumption channels can be avoided by using multiple classes of consumption channels and restricting the use of consumption channels by multicast messages. We provide upper bounds for the number of consumption channels required to avoid deadlocks. In addition, we present a new multicast routing algorithm, column-path, which is based on the well-known dimension-order routing used in many multicomputers and multiprocessors. Therefore, this algorithm could be implemented in existing multicomputers with simple changes to the hardware. Using simulations, we compare the performance of the proposed column-path algorithm with the previously proposed Hamiltonian-path-based multipath and an e-cube-based multicast routing algorithms. Our results show that for multicast traffic, the column-path routing offers higher throughputs, while the multipath algorithm offers lower message latencies. Another result of our study is that the commonly implemented simplistic scheme of sending one copy of a multicast message to each of its destinations exhibits good performance provided the number of destinations is small     

A scalable code dissemination protocol in heterogeneous wireless sensor networks

Code dissemination is currently a major research issue in wireless sensor networks (WSNs).Many studies focus on code dissemination in homogeneous WSNs,mainly using a broadcast approach to solve this problem;few studies on code dissemination in heterogeneous WSNs.Furthermore,broadcasting cannot readily be used to solve the heterogenous WSN code dissemination problem directly,which is where we have focused our attention.We transformed this problem into a minimum non-leaf nodes (MNN) Steiner tree problem.We designed a scalable multicast protocol,named Heterogeneous Sensor Networks Scalable Reprogramming Protocol (HSR) to solve the MNN problem.HSR can build different multicast trees according to different nodes or code modules to disseminate different codes to them.HSR is able to approximate the MNN tree problem to a ratio of ln|R| (R is the set of all destinations) best known lowest bound.Therefore,the communication cost is significantly decreased and the total energy required by WSNs is reduced.We further designed two scalable schemes,special routing log and hops-restricted local broadcast,which compress the multicast tree information and deliver the multicast messages without loss.We also designed a 3-stage pipeline to speed up the transmission of packets,which alleviated interference and hidden terminal issues.We evaluated our design through comprehensive simulations and prototype implementations on Mica2 motes.Experimental results demonstrate that HSR outperforms previous protocols including the most recent studies on Sprinkler and uCast.     

Reconfigurable multicast routing for Networks on Chip

Several unicast and multicast routing protocols have been presented for MPSoCs. Multicast protocols in NoCs are used for cache coherency in distributed shared memory systems, replication, barrier synchronization, or clock synchronization. Unicast routing algorithms are not suitable for multicast, as they increase traffic, congestion and deadlock probability. Famous multicast schemes such as tree-based and path-based schemes have been proposed originally for multicomputers and recently adapted to NoCs. In this paper, we propose a switch tree-based multicast scheme, called STBA. This method supports tree construction with a minimum number of routers. Our evaluation results reveal that, for both synthetic and real traffic loads, the proposed scheme outperforms the baseline tree-based routing scheme in a conventional mesh by up to 41% and reduces power consumption by up to 29%.     

Unicast-based fault-tolerant multicasting in wormhole-routed hypercubes

A unicast-based fault-tolerant multicasting method is proposed for hypercubes, which can still work well when the system contains enough faults. A multicast message may be unable to reach a destination if Hamming distance between the destination and the multicast source is large enough. A multicast message fails if any one of the destinations is unreachable from the source. An effective destination ordering scheme of the destinations is proposed for one-port systems first, it is extended to all-port systems for unicast-based fault-tolerant multicasting. Unreachable destinations from the source based on the local safety information are forwarded to a reachable destination, where the multicast message can be routed reliably. Destination ordering is completed based on Hamming distance. A multiple round p-cube routing scheme is presented for a deadlock-free fault-tolerant routing for each unicast step in hypercubes, where the same virtual channel is used for each round of p-cube routing. Sufficient simulation results are presented by comparing with the previous methods.     

RPT到SPT组播切换丢包问题研究

协议无关组播-稀疏模式是目前应用最广泛的组播路由协议之一。它以汇聚点为基础建立共享树进行数据传输,由接收者发起到源的最短路径树的建立,通过最短路径树进行组播数据的分发。在共享树向最短路径树切换时会发生部分数据包丢失现象。该文分析了RPT向SPT切换时数据包丢失的原因及相关因素,提出了改进和解决方案。     

自适应阈值参数的无线传感器网络组播路由算法

针对现有协议组播树开销难以达到最低的不足,提出了一种新的基于自适应阈值参数的组播路由算法.在初始化阶段对目的节点进行最佳合并分区,初始化完成后则在当前源节点处计算对应各目的节点路径有效因子α的值,自适应地选择阈值参数P对α进行评估,根据评估结果选择当前源节点的下一跳转发节点,直到数据包发送到所有目的节点.仿真结果表明,该算法降低了构建组播树的通信开销,并具有较低的算法复杂度.     

A distributed multicast routing protocol for real-time multicast applications

Multicast routing is establishing a tree which is rooted from the source node and contains all the multicast destinations. A delay bounded routing tree is a tree in which the accumulated delay from the source node to any destination along the tree does not exceed a pre-specified bound. This paper presents a distributed routing protocol which constructs delay bounded routing trees for real-time multicast connections. A constructed routing tree has a near optimal network cost under the delay bound constraint. The proposed algorithm is fully distributed, efficient in terms of the number of messages required, and flexible in multicast membership changes. A large number of simulations have been done to show the network cost of the routing trees generated by our method is better than the other major existing algorithms.     

Neighbor supported reliable multipath multicast routing in MANETs

The limited battery power, unpredictable mobility and large variation of received signal strength in nodes of Mobile Ad Hoc Networks (MANETs) create link and node vulnerability and instability. Multicast routing in MANETs for group communication requires the establishment of reliable links between neighboring nodes called as reliability pair beginning from the source and extending such reliability pairs enroute to the destination. We propose a scheme for Multipath Multicast Routing in MANETs using reliable Neighbor Selection (MMRNS) mechanism. A mesh of multipath routes are established from source to multicast destinations using neighbors that have high reliability pair factor. MMRNS operates in the following phases. (1) Computation of reliability pair factor based on node power level, received differential signal strength between the nodes and mobility. (2) Pruning neighbor nodes that have reliability pair factor smaller than a threshold. (3) Discovery of multipath multicast mesh routes with the help of request and reply packets. (4) Multipath priority assignment based on minimum value of reliability pair factor of a path and information transfer from source to the multicast destinations and (5) route maintenance against link/node failures. The scheme is simulated to evaluate the performance parameters like packet delivery ratio, memory overhead, message overhead, control overhead and packet delays in comparison to the mesh based multicast routing protocols such as On-demand Multicast Routing Protocol (ODMRP) and Enhanced ODMRP (EODMRP). MMRNS performs better than ODMRP and EODMRP as observed from the simulation results.