Linear time distributed construction of colored trees for disjoint multipath routing

Disjoint multipath routing (DMPR) is an effective strategy to achieve robustness in networks where data is forwarded along multiple link- or node-disjoint paths. DMPR poses significant challenges in terms of obtaining loop-free multiple (disjoint) paths and effectively forwarding data over the multiple paths, the latter being particularly significant in datagram networks. One approach to reduce the number of routing table entries for disjoint multipath forwarding is to construct two trees, namely red and blue, rooted at a destination node such that the paths from a source to the destination on the two trees are link/node-disjoint. This paper develops the first distributed algorithm for constructing the colored trees whose running time is linear in the number of links in the network. The paper also demonstrates the effectiveness of employing generalized low-point concept rather than traditional low-point concept in the DFS-tree to reduce the average path lengths on the colored trees.     

无线传感器网络一种不相交路径路由算法

无线传感器网络经常被用来采集物理数据,监测环境变化.由于低功耗无线通信不确定性、链路质量不稳定性以及节点失效等问题,传感器网络很容易导致路由数据包丢失.为了提高网络路由的可靠性,人们提出多路径路由算法.多路径路由中源节点到目的节点的多条路径可能含有公共节点,或者公共边,如果公共节点或者公共链路失效,则这个数据包也丢失,因此又有人提出不相交多路径路由算法.不相交多路径路由算法又分为链路不相交多路径路由算法和节点不相交多路径路由算法.提出了一种不相交路径路由算法,可以将感知节点采集到的数据通过不相交路径传送到汇聚节点,提高路由的可靠性.而且,这个算法还可以很方便地应用到多Sink节点的网络当中.该路由算法用到的路由表大小为|K|,其中|K|表示路径数.算法的运行时间复杂度是O(|L|),其中|L|表示网络中的边数.     

MANET节点不相关的多路路由算法

针对不相关路由路径之闯可能存在特定关键节点问题,提出一种特定节点不相关多路路由算法,通过寻找关键节点,使数据报文经单路径到达关键节点的上一跳节点后,向多条不相关路径的节点进行转发,使数据报文可以同时在多条节点不相关的路径上路由到达目的节点。仿真实验结果表明,如果存在关键节点,该算法能够提高分组投递率、降低端到端延迟;如果不存在关键节点,该算法的性能与节点不相关算法相当。     

MANET节点不相交多路径安全源路由协议

多路径路由实现是移动Ad hoc网络(MANET)可靠运行的有效保证.现有MANET节点不相交多路径路由协议主要关注节点不相交多路径的可实现性和效率问题.针对节点不相交多路径路由协议MNDP协议在主动攻击者安全模型中的安全缺陷,提出了可证明安全的MANET节点不相交多路径动态源路由协议--SMNDP协议.SMNDP协议路由请求算法中,建立了中间节点路由请求消息传播策略的检错机制,SMNDP协议路由应答算法中建立了消息防篡改机制和身份认证机制.基于攻陷的网络拓扑模型,扩展了可模糊路由概念,提出了多路径可模糊路由集合概念和节点不相交多路径源路由协议的安全定义,并应用于SMNDP协议的安全分析.SMNDP协议的安全性可以归约为消息认证码和签名机制的安全性.     

Fault-tolerant routing over shortest node-disjoint paths in hypercubes

This paper presented a routing algorithm that finds n disjoint shortest paths from the source node s to target node d in the n-dimensional hypercube. Fault-tolerant routing over all shortest node-disjoint paths has been investigated to overcome the failure encountered during routing in hypercube networks. In this paper, we proposed an efficient approach to provide fault-tolerant routing which has been investigated on hypercube networks. The proposed approach is based on all shortest node-disjoint paths concept in order to find a fault-free shortest path among several paths provided. The proposed algorithm is a simple uniform distributed algorithm that can tolerate a large number of process failures, while delivering all n messages over optimal-length disjoint paths. However, no distributed algorithm uses acknowledgement messages (acks) for fault tolerance. So, for dealing the faults, acknowledgement messages (acks) are included in the proposed algorithm for routing messages over node-disjoint paths in a hypercube network.     

Guaranteed on-demand discovery of node-disjoint paths in ad hoc networks

In recent years, the low cost and abundance of WLAN products has led to the deployment of self-configuring multihop ad hoc networks. Multipath routing has been increasingly studied to improve network reliability and throughput. However, no existing work guarantees discovery of node-disjoint paths when they exist, which limits their applicability in real networks. This paper presents a theoretical framework that establishes the equivalence between multipath discovery and flow network assignment. This equivalence is used to guarantee the on-demand discovery of an arbitrary number of node-disjoint paths between a pair of nodes as long as they exist. We also present an example protocol that integrates the theoretical framework with the Dynamic Source Routing (DSR) protocol to find two node-disjoint paths, which can be easily extended to finding k node-disjoint paths. Analysis of the example protocol demonstrates a good tradeoff between complexity and capability, particularly when compared with existing on-demand multipath routing protocols. Our simulation data shows the effectiveness of the discovered paths.     

All-to-all disjoint multipath routing using cycle embedding

In this paper, we evaluate the performance of disjoint multipath routing approaches for all-to-all routing in packet-switched networks with respect to packet overhead, path length, and routing table size. We develop a novel approach based on cycle embedding to obtain two node-disjoint paths between all source–destination pairs with reduced number of routing table entries maintained at a node (hence the reduced lookup time), small average path length, and less packet overhead. We study the trade-off between the number of routing table entries maintained at a node and the average length of the two disjoint paths by: (a) formulating the cycle-embedding problem as an integer linear program; and (b) developing a heuristic. We show that the number of routing table entries at a node may be reduced to at most two per destination using cycle-embedding approach if the average length of the disjoint paths are allowed to exceed the minimum by 25%.     

移动WSN节点不相交多路径路由算法

针对移动无线传感器网络不相交多路径路由中的路径断裂问题,提出基于HSV色彩空间的节点不相交多路径路由算法。采用HSV色彩空间模型为每条链路建立数值化的（h,s,v）三元组,使其属于不同的色彩平面,以寻找从源节点到目标节点的多条节点不相交路径。针对节点移动问题,设计基于可变时间间隔链路接收信号强度指示值探测的不相交多路径维护机制,该机制无需借助地理位置信息。实验结果表明,当使用3条路径传输时,该算法的数据传输成功率可达到80％以上,而对比的经典算法均低于70％。此外,其在网络吞吐量、能量消耗等方面也具有较好的性能。     

Transient chaotic neural network-based disjoint multipath routing for mobile ad-hoc networks

Due to mobility of wireless hosts, routing in mobile ad-hoc networks (MANETs) is a challenging task. Multipath routing is employed to provide reliable communication, load balancing, and improving quality of service of MANETs. Multiple paths are selected to be node-disjoint or link-disjoint to improve transmission reliability. However, selecting an optimal disjoint multipath set is an NP-complete problem. Neural networks are powerful tools for a wide variety of combinatorial optimization problems. In this study, a transient chaotic neural network (TCNN) is presented as multipath routing algorithm in MANETs. Each node in the network can be equipped with a neural network, and all the network nodes can be trained and used to obtain optimal or sub-optimal high reliable disjoint paths. This algorithm can find both node-disjoint and link-disjoint paths with no extra overhead. The simulation results show that the proposed method can find the high reliable disjoint path set in MANETs. In this paper, the performance of the proposed algorithm is compared to the shortest path algorithm, disjoint path set selection protocol algorithm, and Hopfield neural network (HNN)-based model. Experimental results show that the disjoint path set reliability of the proposed algorithm is up to 4.5 times more than the shortest path reliability. Also, the proposed algorithm has better performance in both reliability and the number of paths and shows up to 56% improvement in path set reliability and up to 20% improvement in the number of paths in the path set. The proposed TCNN-based algorithm also selects more reliable paths as compared to HNN-based algorithm in less number of iterations.     

无线Ad Hoc网络中增强安全性的多路径路由算法

针对无线ad hoc网络的数据安全性问题,提出了一种增强安全性的多路径路由算法．该算法通过目标节点发送检测数据包的机制,动态维护多路径路由信息的有效性．源节点则根据收到检测包的信息自适应地更新当前的最优传输路径,充分利用路由寻找及维护过程中的信息建立多条可用路径,提供最优的路由方案,并增强了无线ad hoc网络数据传输的安全性．仿真结果表明此算法的数据传输安全性达到了合理的水平．     

A game theoretic framework for stochastic multipath routing in self-organized MANETs

In this paper we propose a game theoretic framework for stochastic multipath routing in mobile ad hoc networks (MANETs). In a MANET, intelligent and adaptive attackers may try to hijack, jam or intercept data packets traveling from source to destination. In our proposed game, at each stage the source node keeps track of the available multiple paths, the residual bandwidth of the paths and the strategy of the attackers from the information gathered during the previous stage. Based on these observations, the source node selects a path for data communication and switching strategy among the multiple established paths between the source node and the destination node. Accordingly, it selects an optimal routing strategy to send data packets to the destination at each stage of the game. Using minimax-Q learning, the selected routing strategy maximizes the expected sum of per stage discounted payoff, which is the utilization of residual bandwidth between a source–destination pair along with the probability that the path is safe. Performance analysis and numerical results show that our proposed scheme achieves significant performance gains in terms of residual bandwidth utilization, average end-to-end delay, packet delivery ratio, routing overhead and security.     

Routing permutations on baseline networks with node-disjoint paths

Permutation is a frequently-used communication pattern in parallel and distributed computing systems and telecommunication networks. Node-disjoint routing has important applications in guided wave optical interconnects where the optical "crosstalk" between messages passing the same switch should be avoided. In this paper, we consider routing arbitrary permutations on an optical baseline network (or reverse baseline network) with node-disjoint paths. We first prove the equivalence between the set of admissible permutations (or semipermutations) of a baseline network and that of its reverse network based on a step-by-step permutation routing. We then show that an arbitrary permutation can be realized in a baseline network (or a reverse baseline network) with node-disjoint paths in four passes, which beats the existing results [M. Vaez et al., (2000)], [G. Maier et al., (2001)] that a permutation can be realized in an n /spl times/ n banyan network with node-disjoint paths in O(n/sup 1/2/) passes. This represents the currently best-known result for the number of passes required for routing an arbitrary permutation with node-disjoint paths in unique-path multistage networks. Unlike other unique path MINs (such as omega networks or banyan networks), only baseline networks have been found to possess such four-pass routing property. We present routing algorithms in both self-routing style and central-controlled style. Different from the recent work in [Y. Yang et al., (2003)], which also gave a four-pass node-disjoint routing algorithm for permutations, the new algorithm is efficient in transmission time for messages of any length, while the algorithm in [Y. Yang et al., (2003)] can work efficiently only for long messages. Comparisons with previous results demonstrate that routing in a baseline network proposed in this paper could be a better choice for routing permutations due to its lowest hardware cost and near-optimal transmission time.     

A multipath routing strategy to prevent flooding disruption attacks in link state routing protocols for MANETs

Multipath routing has been proposed to increase resilience against network failures or improve security in Mobile Ad Hoc Networks (MANETs). The Optimized Link State Routing (OLSR) protocol has been adopted by several multipath routing strategies. They implement Multipoint Relay (MPR) nodes as a flooding mechanism for distributing control information. Ideally, the construction of multiple disjoint paths helps to increase resilience against network failures or malicious attacks. However, this is not always possible. In OLSR networks, partial link-state information is generated and flooded exclusively by the MPRs. Therefore, the nodes only obtain a partial view of the network topology. Additionally, flooding disruption attacks may affect either the selection of the MPRs or the propagation of control traffic information. As a consequence, the chances of constructing multiple disjoint paths are reduced. We present a strategy to compute multiple strictly disjoint paths between any two nodes in OLSR-based networks. We provide mechanisms to improve the view of the network topology by the nodes, as well as handling potential flooding disruption attacks to the multipath construction mechanism in OLSR-based networks. We conduct simulations that confirm our claims.     

基于相关因子的节点不相交的Ad Hoc多路径路由算法

多路径路由算法可以均衡负载、提高可靠性，但是Ad Hoc网络的无线多播特性（WMA）使得多路径数据传输存在严重的；中突隐患，即便是节点不相交的多路径，以并发的方式来进行数据传输的效率并没有理论上的高．为此本文提出基于相关因子的节点不相交的多路径路由算法（NDCF），该算法引入相关因子来衡量多条节点不相交路径以并发的方式进行数据传输时发生；中突的可能性的大小，从而选择冲突可能性最小的节点不相交路径．仿真结果表明，NDCF算法可明显提高数据包的投递率．降低端到端的传输时延．     

基于事件与能量感知的WMSNs节点不相交多路径算法

在无线传感器网络中建立从源节点到目标节点的多条不相交路径,提出了一种基于事件与能量感知的节点不相交多路径算法（ EEDMA）。建立了基于事件与能量感知的多路径模型,基于对事件类型和各路径中节点剩余能量的感知,为不同的事件类型的数据选择合适的路径进行传输。通过仿真结果验证：这种算法为实现异常事件提供了可靠、快速的传输路径,并且为平衡整个网络的能量消耗有重要意义。     

一种累计多路径的移动自组网络路由策略

描述了一种基于多路径移动自组网络按需路由策略.在移动自组网络,由于网络节点的移动性及拓扑结构的易变性,路由成为最受关注的问题.在以前的移动自组网络路由算法中,主要采用的是传统的单路径方式.最近,多路径方式也逐渐出现,因为相对单路径路由而言,多路径为移动自组网络提供的QoS支持更可行、更高效.鉴于现有的移动自组网络多路径策略未能为源节点提供充分的信息,提出了一种新型的移动自组网络多路径路由算法.该算法可以将路由信息保存在源节点中,并依此在源节点中采用替换路径或多路径并发的方式进行数据传输.     

一个低开销的无线传感器网络多径路由协议

针对多对一的周期性数据收集应用,提出一个低开销的逐跳多径路由协议LOMP,综合利用定期和实时估计器评估链路质量,在此基础上实现高质量的多径路由。与现有的多径路由协议相比,LOMP并不提供端到端的节点独立的多径路由,而只是确保在报文的每一跳转发过程中都有多条路径可用。仿真结果表明LOMP能够提高选路质量,以较小的能量开销提高数据传输的可靠性。     

Loop-free constrained path computation for hop-by-hop QoS routing

We present the distributed multi-constrained routing (DMR) protocol for the computation of constrained paths for QoS routing in computer networks. DMR exploits distance vectors to construct a logical shortest multipath (LSM) for each destination with regard to a given optimization metric, from which a set of non-dominated paths are locally derived at each node. As such DMR is able to find feasible paths as well as optimize the utilization of routing resources.DMR operates in line with the hop-by-hop, connectionless routing model assumed in the IP Internet, and maintains instantaneous loop freedom. Nodes running DMR need not maintain a global view of network state (topology and resource information), and routing updates are sent only to neighboring nodes. This is in sharp contrast with all previous approaches that rely on complete or partial network state for constrained path computation, which incurs excessive communication overhead in large networks and is hard to achieve in practice.     

基于生命期预测的移动Ad hoc网络多径路由策略

在移动自组网中,由于网络节点的移动性和拓扑结构的多态性,多路径路由在稳定性,均衡负载方面优于单路径路由,非常适合Ad hoc网络。考虑到移动自组网中节点能量的局限性,在DSR协议的基础上提出了一种新型的多径路由算法。该算法结合节点路径的能量消耗率,预测出链路的生命期,以求找到多条有效路径并进行传输。仿真结果表明,该协议比DSR具有更好的吞吐量和端到端延迟。