基于剩余级别负载均衡的RPL路由协议

低功耗有损网络LLNs(Low-Power and Lossy Networks)中,RPL路由协议可以减少能耗和延长网络生命周期,但是负载的不均衡严重影响了RPL路由协议的性能.据此,提出了一种优化的RPL路由协议—WLB-RPL.该协议以节点剩余能量以及节点平均邻居距离为权重计算剩余级别,并通过动态调整通信半径完成路由构建,以均衡能量.仿真结果表明,改进后的路由协议可以对之前的负载均衡进行更好的优化,达到了理想的效果.     

无线传感器网络的 RPL 路由协议研究

路由协议执行网络拓扑描述、路由选择和数据包转发的功能,影响整个网络的性能和存活时间.现有的路由协议需要发送大量数据包维护网络拓扑,以及大量的存储空间来存储路由条目.由于硬件的限制,无线传感器节点无论是能量,还是其处理能力、存储能力都受到极大的制约.因此,IETF RoLL 工作组提出了一种针对低功耗有损网络的 IPv6路由协议,即 RPL 路由协议.文中对 RPL 路由协议的拓扑构建过程、数据包路由过程和 Trickle 定时器的算法等进行了分析,通过使用 COOJA 仿真工具对其进行仿真,验证了 RPL 路由协议在低功耗有损网络中具有较高的性能     

无线传感器网络中一种基于GEAR协议的节点调度策略

基于无线传感器网络地理能量感知路由(GEAR)协议,提出了一种面向查询式路由的节点调度策略GNSS.该策略针对GEAR协议中存在大量空闲节点和冗余节点的能耗问题,根据周期性路由信息,对节点进行角色分类,不同角色的节点执行不同的调度策略.通过节点调度节省了大量能量消耗,同时减少了数据传输量和通信碰撞带来的开销.仿真结果表明:与改进前的GEAR协议相比,该策略使网络生命周期提高了50%以上.     

基于簇的无线传感器网络密钥管理协议

无线传感器网络密钥管理协议的研究是一个热点问题.针对无线传感器网络体系结构的特征,提出一种基于无线传感器网络簇路由选择协议的集中控制密钥管理协议.将逻辑密钥树协议应用于无线传感器网络中,降低基站节点和普通传感器节点的存储开销和降低普通传感器节点的密钥计算开销,各个簇内采用逻辑密钥树协议作为密钥管理协议,命令控制节点采用Kerberos方法对基站节点实行安全管理.最后对提出的密钥管理协议进行了性能分析.     

RPL路由协议的研究与改进

RPL路由协议在非存储模式下大量通告对象消息聚积,导致网络拥塞,并且转发过程中占用节点缓冲区。针对上述问题,提出一种改进路由协议。通过向子节点发送后向压力消息及时调整Delay DAO定时器的值,从而控制中间节点对DAO消息的转发,利用现有节点的多频特性,在物理上隔离控制信息报文和数据包。实验结果表明,相比于传统低功耗有损网络路由协议的非存储模式,该协议节省了节点缓冲区占用的空间,减少了网络的拥塞和数据包传递过程中的掉包现象。     

无线传感器网络的RPL路由协议研究

路由协议执行网络拓扑描述、路由选择和数据包转发的功能,影响整个网络的性能和存活时间。现有的路由协议需要发送大量数据包维护网络拓扑,以及大量的存储空间来存储路由条目。由于硬件的限制,无线传感器节点无论是能量,还是其处理能力、存储能力都受到极大的制约。因此,IETFRoLL工作组提出了一种针对低功耗有损网络的IPV6路由协议,即RPL路由协议。文中对RPL路由协议的拓扑构建过程、数据包路由过程和Trickle定时器的算法等进行了分析,通过使用COOJA仿真工具对其进行仿真,验证了RPL路由协议在低功耗有损网络中具有较高的性能。     

基于期望寿命的能量均衡RPL研究

目前基于能量均衡的低功耗有损网络路由协议RPL (Routing Protocol for Low power and lossy networks)在网络拓扑构建的过程中由于未考虑备选父节点上一跳节点的期望寿命,从而导致所构建的网络不能较好地实现能量均衡的问题。对此提出一种基于期望寿命的能量均衡RPL(Expected Life Time-based Energy Balance RPL, ELT-EB-RPL)。构造一种复合路由判据,包括传输跳数、期望传输次数和节点期望寿命,同时,节点在选择最优父节点时需综合考虑其备选父节点及备选父节点上一跳节点的期望寿命。在不增加额外控制开销的前提下,提出一种"节点间期望寿命信息通告"策略,以便节点作出正确的路由选择。通过仿真实验对该方案的性能进行了对比分析。结果表明,在不同发包速率下该方案能够有效实现能量均衡和延长网络寿命。     

无线传感器网络中一种基于分簇的能量高效虚拟MIMO传输策略

协作式MIMO技术被认为是传感器网络中有效的节能解决方案之一.针对中小规模传感器网络设计了一种基于分簇的能量高效的协作式虚拟MIMO传输策略(ECCM).在考虑了分布式STBC编码信道训练开销的情况下,分析了该传输策略的系统总体能耗.基于该能耗模型,建立了一种基于端到端的全网能耗最优化模型,并用该模型来求解最优的虚拟MIMO域(分簇)个数、协作节点(虚拟天线)个数以及传输速率等网络通信参数.仿真结果表明,通过选取最优协议参数,即使考虑到电路能耗和信道训练开销,ECCM策略也能显著降低节点传输能耗,延长网络寿命.     

基于受限泛播技术的可伸缩性QoS组播路由协议

随着远程会议、远程教育和交互式仿真等分布式多媒体应用的兴起,组播技术受到网络研究人员的重视.而这些应用的QoS(quality of service)需求又进一步推动了QoS敏感的组播路由协议的发展.在已提出的各种QoS组播路由协议中,如何提高呼叫成功率、增强规模伸缩性、降低控制报文开销,仍然是一个有待探索的问题.提出了一个新的QoS组播路由协议,其基本思想是使路由器只存储其两层邻居节点的可达性信息以及链路的QoS状态信息,以减少路由器存储开销,提高协议的规模伸缩性(scalability).协议采用受限的泛播技术,构造了一个接受节点发起的、采用多路径技术的、分布式路由算法.描述了协议的数据结构、组播树的构造算法,并给出了模拟实验结果.分析表明,基于受限泛播技术的组播路由协议具有节点存储开销小、呼叫接收成功率高等特点.虽然该协议付出了泛播引起的额外带宽开销较大的代价,但是由于协议所需要的控制数据总量不大,加上两层存储结构在一定程度上限制了泛播通信量,因此该方案具有很好的性能.     

OLSR路由协议的改进及其NS2仿真分析

研究了移动Ad hoc网络中的一种典型先应式表驱动路由协议:RFC3626最优链路状态路由协议(Optimized Link State Routing Protocol,OLSR),指出了该协议对MPR(Multipoim Relays)集合选择算法会导致该集合可能存在过多的冗余节点的不足之处,提出了一种改进的OLSR路由协议,通过对原MPR集合中节点的再次排序判断,除去了冗余节点.仿真结果表明:经过改进的OLSR在TC分组的发送数目、节点接受TC分组总数目、平均端到端延迟都得到了很大的改善,从而减少了TC分组的洪泛,提高了网络性能.     

Optimized mobility management for RPL/6LoWPAN based IoT network architecture using the firefly algorithm

RPL (Routing Protocol for low-power and Lossy Networks) is a new attractive model that secures the networks from different routing risks. The dynamic environment and limited resources motivated the research towards identifying a stable, reliable, energy efficient, and scalable routing design. IPv6 over low-power Wireless Personal Area Network (6LoWPAN) is a standard RPL IPv6 routing protocol that provides Low power and Lossy Networks (LLNs) interoperability. In this research work, an energy efficient and optimization-based mobility management framework in RPL routing protocol was proposed (mRPL-based firefly optimization algorithm) to achieve a reliable and stable protocol. From the results, it can be inferred that the proposed system (mRPL+firefly optimizer) showed better performance with regard to the Packet_Delivery_Ratio (PDR), number of hops, End_To_End delay and power consumption when compared to existing systems: RPL, mRPL, mRPL+PSO, and mRPL+ACO. The experimental outcome showed that the proposed system improved the PDR on an average of 2.31% in comparison with existing systems.     

基于三角模算子的RPL协议路由优化算法

针对当前低功耗有损网络拓扑构建及路径选择的参考度量单一,能量均衡性差的问题,提出了一种基于三角模算子的RPL协议路由优化算法。本文阐述了低功耗有损网络路由协议的网络拓扑构建机理和路由过程,基于三角模融合算法,重新定义了网络节点的能量指标和逻辑距离隶属度并进行了融合,更为合理地进行父节点选定,实现数据采集传输业务可靠性和有效性的进一步提升,最后通过实验仿真验证了改进后的路由协议性能。     

无线传感器网络中组播路由协议分析

无线传感器网络由小型无线通信传感设备密集部署形成。组播是一种将数据包从源节点有效传递到一组目的节点的基本路由服务技术。组播协议中,源节点到目的节点的一些路径可由多个目的节点共享,所共享的路径越大,总带宽消耗越低。在分析无线传感器网络基本特征的基础上,对无线传感器网络中现有的组播路由协议进行了分类分析和比较,最后对无线传感器网络组播路由协议的未来发展趋势提出展望。     

基于置信区域设置的低功耗有损网络路由

现有多数低功耗有损网络路由(RPL)协议没有考虑真实环境中移动节点的定位误差。为此,提出基于移动节点置信区域的低功耗有损路由协议,记为KPRPL。KPRPL协议考虑了静态和移动两类节点,并正视真实环境下的定位误差。在静态节点间路由,KPRPL协议考虑传统的期望传输次数(ETX)为路由度量;而针对有移动节点参与的路由,采用新的RPL度量。每个移动节点依据信道条件产生置信区域,利用Kalman滤波修正移动节点位置。再依据经Kalman滤波后的修正位置和方差,移动节点重新构建置信区域,并形成候选锚节点集。最终,移动节点利用端到端ETX估计值,选择最优的路径。仿真结果表明,与传统的RPL协议相比,KPRPL协议提高了在恶劣环境下的可靠性和鲁棒性。     

IRPL: An energy efficient routing protocol for wireless sensor networks

This study aims to overcome the disadvantages of the original RPL (IPv6 Routing Protocol for Low power and Lossy networks) routing protocol (RPL including problems with energy consumption and energy load balance). We developed a relatively balanced RPL – the improved protocol (IRPL). This protocol is based on an efficient clustering algorithm and an effective topology control model of the loop domain communication route. The clustering algorithm can be used to calculate the optimal number of cluster heads by assumption of the network model. Combined with the clustering probability model and the node competition mechanism, the cluster head node in the wireless sensor network was used to complete the clustering process. In the topology control model, the wireless sensor network was divided into concentric rings with equal areas. Nodes determined the best network route, depending on different levels of ring domain and the optimal forwarding communication area defined in this study. Simulation results indicate that the IRPL routing protocol can reduce overall network energy consumption, balance network energy consumption, and prolong network lifetime.     

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     

能量均衡的低功耗有损网络路由协议

针对目前低功耗有损网络路由协议（RPL）中存在节点能耗不均衡、网络生存时间短以及网络后期父节点状态信息更新不及时的问题,提出一种带有电量估算策略的能量均衡RPL（EB-RPL）。首先,构造了一种复合期望传输次数和节点剩余能量的路由度量,通过机制设计使节点在不同时期能自适应地调整网络拓扑;然后,设计了一种基于能量消耗速率的父节点电量估算策略,在不增加额外控制包开销的同时,子节点可以计算父节点电量,作出正确的路由决策;最后,通过实验对比分析了EB-RPL的性能。仿真结果显示,与RPL相比,EB-RPL显著降低了同级节点间功率标准差,并且在不同发包频率和网络规模中,分别平均延长了29.4%和39.4%的平均网络生存时间。EB-RPL能够有效实现能量均衡、显著延长网络生存时间。     

A framework for the IPv6 based implementation of a reactive routing protocol in ns-3: Case study using LOADng

The lightweight on-demand ad hoc distance-vector - next generation (LOADng) is a reactive routing protocol proposed for low-power and lossy networks (LLNs). ITU-T G.9903 standard for power line communication specifies LOADng as its default routing protocol. LOADng establishes bidirectional routes and has routing mechanisms for unicast, multicast and broadcast packets. This paper discusses a general framework for the IPv6 based implementation of a reactive routing protocol in ns-3. The framework is then used to implement LOADng routing protocol in ns-3 as per the latest Internet-draft recommendation. Our implementation of LOADng module in ns-3 is useful to study the potentials and pitfalls of the protocol, to investigate the impact of the various protocol parameters, to derive some non-trivial insights into the protocol behavior, and to compare its performance with other routing protocols proposed for LLNs. Our implementation is flexible enough to be modified and augmented with new features. To reduce the control overhead, the Smart-RREQ concept is incorporated as an extension to the basic framework. Another important feature added to this basic module is the multipath capability. Performance improvements with these new features are verified. The module is also tested for its performance with different route metrics. The framework is useful for implementation of other reactive routing protocols in ns-3.