蜂窝网格的单播路由算法

六角形蜂窝网格是一种具有良好网络拓扑性质的并行多处理机互连网络.蜂窝网格在某些特性上优于二维网格.不过,这种网络不存在单信道最短路径无死锁路由算法.文中针对该网络设计了两个部分自适应无死锁虫孔路由算法.一个是基于转弯模型单信道非最短路径路由算法,另一个则是采用了虚拟双信道的最短路径路由算法.对第二个算法,还进一步使用转弯模型对其改进.通过仿真实验,结果显示这两个路由算法都具有较好的性能.     

二维环网中基于自适应维度气泡路由的组播算法

介绍了一种称为二维环网维度气泡组播路由(2DTDBMR)的新型算法.基于在一套网络中,采用相同的路由策略支持报文的单播操作和组播操作的思想,在二维环网中,基于TADBR自适应路由,设计实现了2DTDBMR组播算法.该组播算法在路由器中实现了多目标路由以及报文复制,而且算法是无死锁的.通过对二维环网中报文所有可能的路由情况进行分析发现当采用2DTDBMR组播算法时,报文最终都可以到达目标点.最后,在自行设计的模拟工具RingNetSim上实现了2DTDBMR组播算法.在RingNetSim上分析了2DTDBMR算法的性能,结果显示环网维度气泡组播算法的性能优异.     

具有不连通子立方体的超立方体中广播路由

基于扩展的局部k—维子立方体连通的超立方体网络Hn,提出了超立方体网络Hn中新的广播容错路由算法。算法分析表明,基于扩展局部k—维子立方体连通的广播路由算法比基于局部k-子立方连通的广播路由算法提高了超立方体网络的容错性和通用性。     

双环Petersen图互联网络及路由算法

Petersen图由于具有短直径和正则性等特性,因此在并行与分布式计算中具有良好的性能.基于双环结构,构造了一个双环Petersen图互联网络DLCPG(k).同时,分别设计了DLCPG(k)上的单播、广播和容错路由算法.证明了DLCPG(k)不但具有良好的可扩展性、短的网络直径和简单的拓扑结构等特性,而且对于10k个节点组成的互联网络,DLCPG(k)还具有比二维Torus以及RP(k)互联网络更小的直径和更优越的可分组性.另外,还证明了其上的单播、广播路由算法的通信效率与RP(k)上的单播和广播路由算法的通信效率相比均有明显的提高.仿真实验表明,新的容错路由算法也具有良好的容错性能.     

二维mesh上的自适应容错路由算法

基于故障块模型提出了二维ｍｅｓｈ上的自适应无死锁容错路由算法。该算法将网络分为两个虚拟网络ＶＩＮ０和ＶＩＮ１。消息根据源与目的节点的相对位置判断进入哪一个虚拟网络。消息在没有遇上故障时经由最短路径路由。算法的容错技术是基于故障环和故障链的概念。最后,将该算法与另一个二维ｍｅｓｈ上的容错路由算法ｆ－ｃｕｂｃ２进行性能比较。     

具有大量错误结点的超立方体网络中的单播路由算法的设计与分析

本文讨论具有大量错误结点的超立方体网络中的单播路由算法，假定Hn是一个局部3－维子立方体连通的n-维超立方体网络并且每一个基本的3－维子立方体中分别最多有1个和2个错误结点，本文提出的单播路由算法能够在线性时间找到路径长度分别为源结点和目的结点之间大约1．5倍和2倍海明距离的次优路径，我们提出的单播路由算法只需要结点知道其邻结点的状态，而无需知道整个网络信息，也就是说，该算法是基于局部信息的，因而该算法具有很强的实际意义。     

蜂窝环上的全广播算法*

主要研究蜂窝环上的全广播路由算法.第一个全广播算法的设计思路是找到一条通过所有节点的路径,关键是确定边界上的一些特殊节点;第二个全广播算法应用了蜂窝环的哈密尔顿性质.假设一个有n个处理机的蜂窝环,前者每个节点有自己专用的路由策略,时间复杂度为3n,因为计算时间往往比数据传送时间低得多,所以总的通信时间可以降低到n;后者...     

低开销的无线传感器网络下行路由协议

下行路由是无线传感器网络路由的一个重要组成部分.利用分布式编址算法为每个节点分配一个下行地址,在转发下行报文时,中间节点利用目的地址即可确定下一跳节点,从而可以通过单播转发实现基站到单个传感器节点的下行通信.在TinyOS上实现了编址算法和下行路由,仿真结果表明和基于广播转发的下行路由协议相比,该协议可以大幅减少报文转发次数,降低了路由开销.同时,因为减少了通信冲突,该下行路由协议对上行数据传输的影响也较小,适合那些既需要上行通信也需要频繁进行下行通信的无线传感器网络使用.     

不规则网络的数学模型实现

基于Duato的新方法论把无死锁路由算法与全适应路由算法联合起来,把每一个物理通道与V个虚拟通道相对应,避免网络中消息传递时发生等待死锁,从而使消息等待时间最小。计算每个消息的平均等待时间,再汇总计算所有消息的平均等待时间,从而使建立的数学模型在估算网络性能时有很高的准确性。该模型提供了计算下一跳的地址的方法,实现了对网络性能的计算。     

基于局部扭曲立方体的多播路由算法

局部扭曲立方体是一种新提出来用于并行计算的互联网络。经研究发现,局部扭曲立方体中已有最小路由算法存在着死锁。因此,在原有算法的基础上,提出了一种新的无死锁路由算法并给出了无死锁证明。利用将物理通道分成两条虚拟通道进而形成两个不相交的虚拟网络,将不同的点对之间的路由限定在某一个虚拟网络中,从而有效地避免了死锁的产生。同时,利用一个局部扭曲立方体可由两个低维子立文体和2-扭曲立方体构成这一性质,在局部的低维子立方体和2-扭曲立方体中均采用自适应路由,从而提高了算法的自适应性。在此基础上提出了一种多播路由算法。     

故障三维Mesh网络中的容错路由

该文在k—Mesh子网连通概念的基础上提出了三维Mesh网络中局部k—Mesh子网弱连通的概念,证明了局部k—Mesh子网弱连通的三维Mesh网络存在全局连通性。基于局部k—Mesh子网弱连通的三维Mesh网络提出了单播、广播容错路由算法。这些算法提高了容错能力且是基于局部信息的,因而具有很好的实际意义。     

一种蓝牙分散网拓扑结构创建和网络路由分布式算法

蓝牙分散网潜在的广阔应用前景使它逐渐成为自组网络研究热点之一。蓝牙分散网所具有的特殊限制和特性给有效创建分散网络拓扑结构和网络路由带来了挑战。提出和分析了一种分布式蓝牙分散网拓扑结构创建算法和以此为基础的网络路由算法。它是一种简单有效的可递归算法，具有良好的扩展性。文章假定通信距离内的两结点间能建立物理连接。通过数学证明和仿真试验，算法具有以下性能：时间复杂度为O（log N)，消息复杂度为O（N），分散网网络直径为O（log N)。利用特殊的地址表示法，运行简单的路由算法可实现单播和广播路由。     

内容发布订阅系统的组播路由

基于内容的发布订阅系统多数采用泛洪和匹配优先的路由算法。本文提出了基于事件空间划分的发布订阅系统的实现方法,采用组播的方式实现了目标代理到多个订阅者之间的通知路由算法。与采用贪婪路由思想的单播路由算法相比较,该算法提高了在通知路由阶段的发布订阅系统的路由效率。算法对解决基于内容的发布订阅系统中相关的路由问题具有重要的作用和意义。最后给出了算法的仿真实验。     

服务于TCP的高移动性无线网络路由协议

提出了一种基于地理位置信息的无线网络路由协议LADRU,以增强高移动性网络TCP的性能。协议采用单播和广播相结合的礼花式广播来减少系统开销,以随机竞争方式探测路由,减少寻找新路由的代价。通过估计网络节点的运动速率来自动调节路由探测周期,使路由得到及时更新。采用标签路由方法传递数据包,解决源路由方式数据包头过大和路由切换问题。仿真结果表明LADRU能有效地提高数据传输率和系统吞吐率。     

A broadcast algorithm for all-port wormhole-routed torus networks

A new approach to broadcast in wormhole-routed two- and three-dimensional torus networks is proposed. The underlying network is assumed to support only deterministic, dimension-ordered unicast routing. The approach extends the graph theoretical concept of dominating nodes by accounting for the relative distance-insensitivity of the wormhole routing switching strategy. The proposed algorithm also takes advantage of an all-port communication architecture, which allows each node to simultaneously transmit messages on different outgoing channels. The resulting broadcast operation is based on a tree structure that uses multiple levels of extended dominating nodes(EDNs). Performance results are presented that confirm the advantage of this method over other approaches     

Multi-constraint multi-objective QoS aware routing heuristics for query driven sensor networks using fuzzy soft sets

In this paper, a fuzzy based distributed power aware routing scheme considering both energy and bandwidth constraints, especially for query driven applications in the asynchronous duty-cycled wireless sensor networks are devised. The proposed multi-constraint, multi-objective routing optimization approach under strict resource constraints guarantees reliability and fast data delivery along with efficient power management in spite of unreliable wireless links and limited power supply. In query driven applications, the request from the sink to the individual sensor node will be a broadcast message, whereas the individual sensor nodes replies back to sink as unicast messages. In the proposed work, the fuzzy approach and “A Star” algorithm are utilized for satisfying energy and bandwidth constraints to route the broadcast messages of the sink while querying all the sensor nodes in the network. Every node will be provided with a guidance list, which is used to decide the next best neighbor node with good route quality for forwarding the received multi-hop broadcast messages. The route quality of the every node is estimated with fuzzy rules based on the network parameters such as maximum remaining energy, minimum traffic load and better link quality to increase the network lifetime. The provision of overhearing the broadcast messages and acknowledgements within the transmission range minimizes the effort to search for the active time of nodes while routing the broadcast messages with asynchronous scheduling. Further, in the proposed work only the time slot of its nearest neighbor relay node (to which packets are to be forwarded) is learnt to reduce the number of message transmissions in the network. For the unicast message replies, the fuzzy membership function is modified and devised based on the routing metrics such as higher residual energy, minimum traffic loads and minimum hop count under energy and bandwidth constraints. Also, the multi-hop heuristic routing algorithm called Nearest Neighbor Tree is effectively used to reduce the number of neighbors in the guidance list that are elected for forwarding. This helps to increase the individual sensor node’s lifetime, thereby maximizes the network lifetime and guarantees increased network throughput. The simulation results show that the proposed technique reduces repeated transmissions, decreases the number of transmissions, shortens the active time of the sensor nodes and increases the network lifetime for query driven sensor network applications invariant to total the number of sensor nodes and sinks in the network. The proposed algorithm is tested in a small test bed of sensor network with ten nodes that monitors the room temperature.     

一种基于AODV改进的城市车载自组网路由协议研究

针对城市环境下车载自组网的特点及AODV协议广播式路由探测的不足,采用贪婪转发的单播式路由探测和经典AODV协议的广播式路由探测相结合的路由探测方式,并且单播路由探测在选择下一跳转发节点时同时考虑贪婪转发和链路稳定两个因素,减少了广播帧的发送,提高了路由的稳定性。仿真实验表明,改进后AODV协议比经典AODV协议更加适合城市车载自组网。     

Localized topology control for unicast and broadcast in wireless ad hoc networks

We propose a novel localized topology-control algorithm for each wireless node to locally select communication neighbors and adjust its transmission power accordingly such that all nodes together self-form a topology that is energy efficient simultaneously for both unicast and broadcast communications. We theoretically prove that the proposed topology is planar, which meets the requirement of certain localized routing methods to guarantee packet delivery; it is power-efficient for unicast - the energy needed to connect any pair of nodes is within a small constant factor of the minimum; it is also asymptotically optimum for broadcast - the energy consumption for broadcasting data on top of it is asymptotically the best among all structures constructed using only local information; it has a constant bounded logical degree, which will potentially save the cost of updating routing tables if used. We further prove that the expected average physical degree of all nodes is a small constant. To the best of our knowledge, this is the first localized topology-control strategy for all nodes to maintain a structure with all these desirable properties. Previously, only a centralized algorithm was reported. Moreover, by assuming that the node ID and its position can be represented in O(log n) bits for a wireless network of n nodes, the total number of messages by our methods is in the range of theoretical results are corroborated in the simulations.     

The influence of broadcast traffic on IEEE 802.11 DCF networks

The performance of the IEEE 802.11 protocol depends on multiple factors. One of them is related with the relative amounts of broadcast and unicast traffic in the total load due to the coexistence of the different transmission schemes applied to each of these types of traffic. This paper presents an analytical model to compute the 802.11 probability of a successful transmission of a frame and the average transmission delay assuming the presence of both unicast and broadcast traffic. Several realistic issues are addressed, as pre- and post-transmission backoffs, variable frame length and finite MAC buffers. Broadcast frame transmission has a swifter algorithm. When compared to broadcast, unicast frame transmission exhibits a more reliable scheme to avoid a frame from being discarded when it collides, but creates a trade off as it can introduce larger transmission delays. Simulation results are presented and compared to the analytical computations validating the model’s accuracy. Finally, interesting results related with the influence of the amount of broadcast or unicast traffic on the network’s performance for non-saturation and saturation operating zones are discussed for different data transmission rates. This is particularly relevant as most of the ad hoc routing algorithms rely heavily on broadcast.     

蚁群算法在无线传感器网络路由中的应用研究

设计合理的路由算法是无线传感器网络中的核心问题之一。基于蚁群算法提出了一种可用于无线传感器网络的单播路由算法,该算法利用蚁群算法正反馈及分布式计算的特点寻找从源节点目的节点的最少跳数路径。仿真实验证明了该算法是合理的及有效的,具有可扩展性的特点,同时在收敛速度和鲁棒性上优于典型的单播路由算法。