一种控制消息广播与合并策略的低开销路由算法

针对现有基于社区的机会社会网络多副本消息传输机制中网络控制开销较大和网络资源浪费的问题,提出了一种基于广播策略的机会社会网络低开销路由算法.该算法采用了"ACK消息快速产生机制"和"控制消息合并机制"两种新机制,能够有效减少网络中数据消息副本不必要的转发次数和降低网络控制开销.理论分析和仿真验证表明,相较于现有的基于社区的消息机会传输路由算法和基于重叠社区的消息机会转发路由算法,所提算法能有效减少网络控制开销和节省网络资源.     

容迟网络中一种改进型ProPHET路由算法研究

由于ProPHET路由没有限制网络中消息数量,因此其网络开销很高。文章提出了新的消息转发度量化函数,并据此给出一种改进的概率路由算法P-DFM（ProPHET Based on DFM）。该算法利用节点与目的节点的接触概率和节点间的相遇频率来计算节点的消息转发度,通过比较节点的DFM决定转发消息的副本数目。采用TheONE对Epidemic路由、ProPHET路由及P-DFM路由进行仿真,结果表明提出的P-DFM算法有效地提高了消息投递率,降低了网络开销的成本。     

无线自组织网络中一种拥塞意识的多径路由算法

提出了无线自组织网络中一种拥塞意识的多径路由算法。该算法在路由发现过程中,综合节点的队列长度和路径跳数来动态确定路由请求消息的转发概率,可以在保证路由请求消息有一定送达率的条件下,降低路由开销;在路径选择和流量分配过程中,综合考虑节点的队列长度和路径质量作为路由度量,发现流量高吞吐量低拥塞路径,并基于该度量值进行流量分配。仿真结果显示,所提出的多径路由算法能有效提高网络性能。     

一种基于动态概率转发的AODV路由协议

在Ad hoc网络(自组织网络)的路由建立过程中,由于AODV(Ad hoc按需距离矢量)路由采用洪泛方式转发RREQ(路由请求)消息会产生很多不必要的重传,很可能引发广播风暴而影响网络性能。文章提出了一种基于动态概率转发RREQ消息的改进方案,该方案根据邻居节点的个数选择不同的概率转发RREQ消息。仿真结果表明,在网络节点较多且网络比较稠密的情况下,改进方案能有效减少网络端到端时延,提高网络吞吐量和分组投递率。     

一种基于节点能量的机会网络概率路由算法

在机会网络中,节点之间可能不存在端到端的路径.为了节省网络中节点消耗的能量,在概率路由算法的基础上提出了一种基于节点能量的概率路由算法(Energy-based Probabilistic Routing Protocol using History of Encounters and Transitivity,EBPROPHET).首先,计算两个节点相遇时节点的通信开销,然后相遇节点的剩余能量作为一个参量引入算法,选择节点剩余能量多的节点作为转发节点,最后,进行消息的转发.仿真表明,EB-PROPHET算法具有良好的路由性能,降低了整个网络的能量消耗,延长了网络的生存周期.     

基于网关信息素更新的MANET接入Internet开销控制方法

 寻找可用网关是MANET接入Internet过程中产生开销最大的一个环节。为了有效控制接入过程中的路由开销,根据蚂蚁寻径与移动节点寻找网关的相似性,提出了一种基于网关信息素更新的接入网络开销控制算法。该算法模仿蚁群算法中信息素更新方式,运用路由应答报文中携带的信息对网关信息素进行更新。节点在寻路时根据路径上的信息素浓度、链路带宽和时延等参数计算转发概率并进行转发。通过运用NS2.29对该算法进行仿真,结果表明该算法虽然平均端到端时延略有增加,但是有效地减少了归一化路由开销,并提高了分组投递率,验证了算法的有效性。     

基于多Agent强化学习的Ad hoc网络跨层拥塞控制策略

该文首先证明基于MAC层竞争造成的网络拥塞模型中存在纳什均衡点。其次,基于WOLF-PHC学习策略提出了一种跨层拥塞控制(WCS)机制。它在路由层中选择一对去耦合节点作为转发节点,同时在MAC层对源节点的发送数据进行分流,从而提高链路的空间重用性。仿真结果表明:在不需要交互任何信息的情况下,通过节点之间的相互博弈以后,采用WOLF-PHC算法能够找到每个节点的最佳分流概率进而使整体网络吞吐量达到最大值;同时当外界环境发生改变时,该算法能够较快地找到新的最佳分流概率从而实现对环境的自适应能力。     

ZigBee网络自剪裁路由算法

ZigBee网络中的AODVjr算法通过全网广播路由请求RREQ消息而获得分组发送的最短路径,但节点大量广播RREQ消息增加了网络控制开销,导致网络节点耗能剧增,同时网络堵塞的可能性也大大提升。针对AODVjr算法存在的网络节点耗能剧增问题,在AODVjr算法基础上,结合节点邻居表,提出筛选RREQ消息转发节点,从而限制RREQ消息转发次数的路由算法Zig Bee树节点自剪裁转发算法(ZigBee On-tree Self-pruning Rebroadcast Algorithm,ZOSR)和ZigBee转发节点选择算法(ZigBee On-tree Forwarding Node Selection Algorithm,ZOFNS)。仿真结果表明,算法能有效降低网络节点的转发次数,从而降低网络整体功耗,延长网络工作时间。     

ad hoc网络中一种基于信任模型的机会路由算法

由于ad hoc网络具有缺乏足够的物理保护、拓扑结构动态变化、采用分布式协作、节点的带宽和计算能力有限等特点,导致传统的路由安全机制不再适合ad hoc网络路由协议的设计。最近当前研究热点之一的机会路由能够在链路不可靠的情况下充分利用无线广播和空间多样性的特性提高网络的吞吐量。因此,考虑在机会路由中引入信任相似性概念设计信任机会路由,建立了基于节点信任度和最小成本的信任机会转发模型,提出了最小成本的机会路由算法MCOR,并对算法进行了理论上的分析和证明。最后采用仿真实验对该算法进行验证,又与经典机会路由协议ExOR以及其他经典的信任路由协议TAODV和Watchdog-DSR进行性能对比。仿真结果表明,MCOR算法能够防范恶意节点的攻击,在吞吐量、端到端时延、期望转发次数(ETX)和成本开销等方面都比其他3种协议表现出性能上的优势。     

基于动态分段网络编码的DTN高效路由算法

针对DTN现有的动态分段网络编码(Dynamic Segmented Network Coding,DSNC)路由算法在编码包头部存在冗余字段、ACK反馈阶段存在冗余开销和节点因无序转发编码包而影响数据包端到端时延等问题,提出基于动态分段网络编码的DTN高效路由算法—ERBNC(Efficient Routing Based on dynamic segmented Network Coding).该算法通过采取压缩编码包头部字段、删除冗余的ACK分组、设置编码包的发送优先级等措施以减少网络开销和数据包平均端到端时延.仿真结果表明,与DSNC算法相比,ERBNC算法在网络开销和端到端时延方面的性能均得到改善.     

一种低时延的短波自组网优化链路状态路由协议

优化链路状态路由(Optimized Link State Routing,OLSR)协议是一种先验式路由协议,网络中的所有节点通过周期性地发送控制消息来计算全网路由信息。在短波自组织网络中,节点周期性地发送控制消息会占据大量的信道资源,大幅增加网络的控制开销,浪费短波有限的带宽资源,导致网络通信性能急剧下降。其次,受到地形地貌、天线方向和接收性能的个体差异等影响,造成无线链路不稳定,导致网络中存在非对称链路,增加了通信端到端时延。为此,提出了一种低时延的短波自组网OLSR协议。该协议在执行MPR(Multipoint Relay)选择算法时综合考虑了节点的连接度和链路可靠性,在优化MPR节点个数的同时选择链路可靠性较大的节点作为MPR节点,在进行路由选择时能够利用网络中的非对称链路。仿真结果表明,该协议能优化数据包投递成功率、吞吐量、端到端时延和网络控制开销等性能指标。     

Load balancing routing with queue overflow prediction for WSNs

The ease of deployment of Wireless Sensor Networks (WSNs) makes them very popular and useful for data collection applications. Nodes often use multihop communication to transmit data to a collector node. The next hop selection in order to reach the final destination is done following a routing policy based on a routing metric. The routing metric value is exchanged via control messages. Control messages transmission frequency can reduce the network bandwidth and affect data transmission. Some approaches like trickle algorithm have been proposed to optimize the network control messages transmission. In this paper, we propose a collaborative load balancing algorithm (CoLBA) with a prediction approach to reduce network overhead. CoLBA is a queuing delay based routing protocol that avoids packet queue overflow and uses a prediction approach to optimize control messages transmission. Simulation results on Cooja simulator show that CoLBA outperforms other existing protocols in terms of delivery ratio and queue overflow while maintaining a similar end-to-end delay.

     

Bayesian inference approach for establishing efficient routes in wireless ad-hoc networks

Mobile ad hoc networks (MANETs) are dynamic wireless networks that have no fixed infrastructures and do not require predefined configurations. In this infrastructure-less paradigm, nodes in addition of being hosts, they also act as relays and forward data packets for other nodes in the network. Due to limited resources in MANETs such as bandwidth and power, the performance of the routing protocol plays a significant role. A routing protocol in MATET should not introduce excessive control messages to the network in order to save network bandwidth and nodes power. In this paper, we propose a probabilistic approach based on Bayesian inference to enable efficient routing in MANETs. Nodes in the proposed approach utilize the broadcast nature of the wireless channel to observe the network topology by overhearing wireless transmissions at neighboring nodes in a distributed manner, and learn from these observations when taking packet forwarding decision on the IP network layer. Our simulation results show that our routing approach reduces the number of control message (routing overhead) by a ratio up to 20 % when the network size is 60 nodes, while maintaining similar average route establishment delay as compared to the ad-hoc on demand routing protocol.     

一种基于最短路径树的无线Ad hoc网络拓扑维护算法

该文主要研究了无线Ad hoc网络中节点失效的情况下,如何维护网络的连通性和拓扑的性能,并且尽可能地降低拓扑维护的开销。提出了基于最短路径树的拓扑维护算法。该算法在拓扑变化时首先触发失效节点的邻节点响应(即重新运行拓扑控制算法),在不增加额外通信开销的情况下,响应的节点根据相互发送的Hello分组来判断网络是否连通;如果不能确定网络是连通的,再触发失效节点的其它可达邻近节点响应。仿真研究表明,算法显著地减少了拓扑维护的开销,维护后的拓扑结构在功率有效性和功率扩展因子等方面也取得了好的性能。     

基于博弈的协作路由算法

协作虚拟多输入多输出（VMIMO）传输是一种有效的无线传输性能优化技术。将物理层协作VMIMO技术和网络层路由选择技术相结合,设计跨层VMIMO路由选择方案可以利用VMIMO的分集增益,显著地降低网络传输能耗。如何设计VMIMO协作路由协议抵抗无线网络的自私节点和欺骗行为,保证高数据转发率和低传输能耗成为路由设计中的重大挑战。为了提高自私网络的VMIMO路由性能,提出了一种基于重复路由博弈的VMIMO协作路由算法。该算法将网络划分成多个Group、Group间使用VMIMO传输数据。将Group间路由选择过程建模为重复路由博弈过程。为了提高数据转发的成功率,提出适用度函数评估节点参与数据分组转发的信誉。以此为基础,提出基于适用度的路由选择子算法和路由转发子算法。理论证明所提重复路由博弈可达到帕累托最优。仿真实验结果表明本算法可以促进自私节点相互合作,可获得较高的数据转发率,较好地减少数据传输时延以及能量消耗。     

城市环境VANETS下的基于beacon控制的路由方案

车载网络(Vehicular ad hoc networks,VANETs)是一种特殊形式的网络,具有节点高速移动、拓扑频繁的变化的特性。这些特性为消息的传播带来挑战。路由机制是实现消息传递的关键因素。地理位置路由被广泛地应用于VANETS,要求节点周期广播beacon消息。然而,节点周期地广播beacon消息,降低了路由性能,特别是在城市区域,由于节点密集,每个节点均广播beacon消息,恶化了路由性能。为此,针对城市环境,提出基于beacon控制的路由协议RPBC(Routing protocol with beacon control)。在RPBC中,并非每个节点广播beacon消息,而设置有效的机制选择部分节点广播,从而降低了beacon冗余,同时,采用最短路径算法,减少数据传输跳数。仿真结果表明,提出的RBPC在分组投递率、端到端传输时延以及路由开销方面均有较好的性能。     

An improved distance‐based ant colony optimization routing for vehicular ad hoc networks

Vehicular ad hoc network (VANET) has earned tremendous attraction in the recent period due to its usage in a wireless intelligent transportation system. VANET is a unique form of mobile ad hoc network (MANET). Routing issues such as high mobility of nodes, frequent path breaks, the blind broadcasting of messages, and bandwidth constraints in VANET increase communication cost, frequent path failure, and overhead and decrease efficiency in routing, and shortest path in routing provides solutions to overcome all these problems. Finding the shortest path between source and destination in the VANET road scenario is a challenging task. Long path increases network overhead, communication cost, and frequent path failure and decreases routing efficiency. To increase efficiency in routing a novel, improved distance‐based ant colony optimization routing (IDBACOR) is proposed. The proposed IDBACOR determines intervehicular distance, and it is triggered by modified ant colony optimization (modified ACO). The modified ACO method is a metaheuristic approach, motivated by the natural behavior of ants. The simulation result indicates that the overall performance of our proposed scheme is better than ant colony optimization (ACO), opposition‐based ant colony optimization (OACO), and greedy routing with ant colony optimization (GRACO) in terms of throughput, average communication cost, average propagation delay, average routing overhead, and average packet delivery ratio.     

Asymptotically Optimal Energy-Aware Routing for Multihop Wireless Networks With Renewable Energy Sources

In this paper, we develop a model to characterize the performance of multihop radio networks in the presence of energy constraints and design routing algorithms to optimally utilize the available energy. The energy model allows us to consider different types of energy sources in heterogeneous environments. The proposed algorithm is shown to achieve a competitive ratio (i.e., the ratio of the performance of any offline algorithm that has knowledge of all past and future packet arrivals to the performance of our online algorithm) that is asymptotically optimal with respect to the number of nodes in the network. The algorithm assumes no statistical information on packet arrivals and can easily be incorporated into existing routing schemes (e.g., proactive or on-demand methodologies) in a distributed fashion. Simulation results confirm that the algorithm performs very well in terms of maximizing the throughput of an energy-constrained network. Further, a new threshold-based scheme is proposed to reduce the routing overhead while incurring only minimum performance degradation.     

基于跨层设计的无线传感器网络节能双向梯度路由算法

针对现有无线传感器网络梯度路由算法在下行路由创建过程和能量更新机制中存在冗余控制开销的问题,该文提出一种采用跨层和功率控制机制,具有节能功能的双向梯度路由算法(Cross-layer Energy-efficient Bidirectional Routing,CEBR):无需使用专门的控制分组,采用源路由方式以较小开销建立从Sink节点通往传感器节点的下行路由;通过跨层信息共享,定期采集节点剩余能量信息并按需发布;设计使用含跳数和节点剩余能量的合成路由度量标准,减少节点能量和网络带宽消耗的同时均衡节点能耗;结合RSSI(Received Signal Strength Indication)测距实现节点发射功率控制从而在数据及查询分组发送过程中节约节点能量。理论分析表明了CEBR的有效性;仿真结果显示:与现有的典型相关算法相比,CEBR能够在建立双向梯度路由的前提下,至少降低34.5%的归一化控制开销和27.12%的数据分组平均能耗,并使网络生存期延长18.98%以上。     

Stability-Based RREQ Forwarding Game for Stability-Oriented Route Discovery in MANETs

In traditional stability-oriented route discovery of mobile ad hoc networks, in-between nodes need to rebroadcast identical route request (RREQ) packets, which contain same source node ID and broadcast sequence number, to discover more stable route, yet it increases routing overhead and data transmission delay obviously. Therefore, a stability-oriented route discovery algorithm is proposed to limit routing overhead and decrease transmission delay. In this algorithm, all neighbor nodes of some node will play a mix strategy game named stability-based RREQ forwarding game after receiving an identical RREQ, and independently determine the RREQ forwarding probability based on Nash equilibrium, respectively. The simulation results show that the proposed stability-oriented route discovery algorithm not only reduces routing overhead and transmission delay effectively, but also improve other routing performance.