Average Routing Path Length Research Articles

The Construction of a Virtual Backbone with a Bounded Diameter in a Wireless Network

We usually use a digraph to represent a wireless network (WN). Correspondingly, a connected dominating set (CDS) of the digraph is usually used to denote a virtual backbone (VB) of the corresponding WN. In this article, focusing on the problem of a minimum strongly connected dominating and absorbing set (MSCDAS) with a bounded diameter (or guaranteed routing cost) for a digraph, which is strongly connected, we introduce two algorithms. One is called the guaranteed routing cost strongly connected dominating and absorbing set (GOC-SCDAS), which can generate a strongly connected dominating and absorbing set (SCDAS) with a performance ratio 14.4k+1/22 in respect of the optimal solution. Another is called the α guaranteed routing cost strongly connected bidirectional dominating and absorbing set (α-GOC-SCBDAS), which can generate a strongly connected bidirectional dominating and absorbing set (SCBDAS) with a performance ratio 8.8443k+1/22k+1/22 in respect of the optimal solution and a better routing cost, where k=rmax/rmin and rmin,rmax is the transmission range of nodes in the network. Through the simulation experiments, we obtain the conclusion that in terms of the diameter and average routing path length (ARPL) of CDS, the outputs of our algorithms are better than those of the algorithm in (Du et al. 2006).

A cost-effective low-latency overlaid torus-based data center network architecture

In this paper, we present the design, analysis, and implementation of a novel data center network architecture named CLOT, which delivers significant reduction in the network diameter, network latency, and infrastructure cost. CLOT is built based on a switchless torus topology by adding only a number of most beneficial low-end switches in a proper way. Forming the servers in close proximity of each other in torus topology well implements the network locality. The extra layer of switches largely shortens the average routing path length of torus network, which increases the communication efficiency. We show that CLOT can achieve lower latency, smaller routing path length, higher bisection bandwidth and throughput, and better fault tolerance compared to both conventional hierarchical data center networks as well as the recently proposed CamCube network. Coupled with the coordinate based geographical addresses and credit based flow control, the specially designed POW routing algorithm helps CLOT achieve its maximum theoretical performance. Besides, an automatic address configuration mechanism and malfunction detection mechanism are provided to facilitate the network deployment and configuration. The sufficient mathematical analysis and theoretical derivation prove both guaranteed and ideal performance of CLOT.

An efficient probability routing algorithm for scale-free networks

To better utilize hub nodes within a network, this paper proposed an efficient probability (EP) routing algorithm which features using the importance degree to target critical nodes and subsequently redistribute incoming packets. Simulation results reveal that the proposed strategy is able to improve the network capacity in comparison to the shortest path (SP) routing strategy and the centrality-degree-based probability path (PP) routing algorithm. Moreover, the average routing path length of the EP is over 30% shorter than that of the PP, though it is 10% longer than that of the SP.

A Hybrid Approach for Path Vulnerability Matrix on Random Key Predistribution for Wireless Sensor Networks

In this paper, we address the problem of physical node capture attack from an adversarial view. In this type of attack, an adversary intelligently captures the node(s) and extracts the cryptographic information to destroy the privacy, safety and reliability of the network. We propose a novel hybrid approach for constructing the path vulnerability matrix that maximizes the attacking efficiency and lowers the resource expenditure of the adversary. The main strength of the proposed matrix lies in incorporating various criteria such as the type of application running on the nodes, capturing cost, key dominance ranking, articulation point and intersecting shortest path nodes in estimating the vulnerability. The location of the data sink is considered as a major factor in estimating the vulnerability of the nodes in the network. The proposed matrix is compared with existing attacking strategies in terms of the number of attacking rounds, energy cost and fraction of compromised traffic. Although in this paper, we have considered adversarial point of view but the proposed matrix can be extended for the defender application also. The path vulnerability matrix provides vulnerability estimation that can be used to analyze system security weakness and helps to defend against them effectively and efficiently. The performance of proposed approach has been validated with respect to average path compromise ratio, average routing path length and average route successful ratio. We have also introduced an attack resistant random key predistribution scheme based on the proposed approach and the results confirm its effectiveness in decreasing node capture impact.

An energy efficient and load balanced distributed routing scheme for wireless sensor networks with holes

Abstract In this paper we present a new approach to route packets in the presence of routing holes. In our proposal, nodes cooperate to determine the approximate polygon of a specific hole and then exchange information about the approximate polygon. Based on the hole covering parallelogram and the hole view angle of a specific node, packets can be forwarded along an escape route that bends around the hole. We rigorously prove that the Euclidean stretch of an escape route is bounded. Simulation results show that the proposed scheme can save more than 16% of the energy consumption and 7% of the network lifetime in the comparison with existing routing algorithms. The average length of routing paths in our approach is less than 60% of other routing schemes.

HyCube: A distributed hash table based on a variable metric

Distributed Hash Tables (DHT) proved to be scalable decentralized systems providing efficient resource location. This paper concentrates on efficiency and resilience to node failures of DHT systems and presents a novel model of a distributed hash table based on a hierarchical hypercube geometry, called HyCube. The DHT geometry, the choice of the metric defining logical distances between nodes, and the routing algorithm have fundamental influence on routing efficiency and resilience. The use of the one-dimensional model (placing the nodes logically on a ring) allows the nodes to maintain sets of references called sequential neighbors - certain numbers of neighbors that are the closest existing nodes in both directions on the ring. Such a model yields a very high level of resilience to node failures. The new approach, presented in the paper, employs a variable multi-dimensional metric adopting the Steinhaus transform. Routing, lookup and search algorithms are discussed, as well as routing table nodes selection and self-organization techniques. It is shown that the new approach allows reaching a higher level of resilience to node failures, as well as a shorter average routing path length than with the use of the sequential neighbors sets.

Towards cost-effective and low latency data center network architecture

This paper presents the design, analysis, and implementation of a novel data center network architecture, named NovaCube. Based on regular Torus topology, NovaCube is constructed by adding a number of most beneficial jump-over links, which offers many distinct advantages and practical benefits. Moreover, in order to enable NovaCube to achieve its maximum theoretical performance, a probabilistic oblivious routing algorithm PORA is carefully designed. PORA is a both deadlock and livelock free routing algorithm, which achieves near-optimal performance in terms of average routing path length with better load balancing thus leading to higher throughput. Theoretical derivation and mathematical analysis together with extensive simulations further prove the good performance of NovaCube and PORA.

A Virtual Coordinate-Based Bypassing Void Routing for Wireless Sensor Networks

To solve the routing void problem in geographic routing, high control overhead and transmission delay are usually taken in wireless sensor networks. Inspired by the structure composed of edge nodes around which there is no routing void, an efficient bypassing void routing protocol based on virtual coordinates is proposed in this paper. The basic idea of the protocol is to transform a random structure composed of void edges into a regular one by mapping edge nodes coordinates to a virtual circle. By utilizing the virtual circle, the greedy forwarding can be prevented from failing, so that there is no routing void in forwarding process from source to destination and control overhead can be reduced. Furthermore, the virtual circle is beneficial to reduce average length of routing paths and decrease transmission delay. Simulations show the proposed protocol has higher delivery ratio, shorter path length, less control packet overhead, and energy consumption.

An Efficient Bypassing Void Routing Protocol Based on Virtual Coordinate for WSNs

Inspired by the structure composed of edge nodes without routing voids, a routing protocol based on virtual coordinates is proposed in this letter. The basic idea of the proposed protocol is to transform a random structure composed of edge nodes into a regular one by mapping edge nodes to virtual nodes on a virtual circle. The virtual circle can prevent greedy forwarding from failing by proposed strategies, so that control overhead and the average length of routing paths can be reduced. Simulations show the proposed protocol has higher delivery ratio, shorter path length, and less control packet overhead and energy consumption.

An Efficient Timer Based Minimum Path D-Equivalence CDS Construction for Wireless Adhoc Networks

Objective: The main intent of this research is to enhance the network capacity and compute the shortest path for reducing congestion in the wireless adhoc networks. Methods: In this manuscript, an innovative technique is introduced which is used to enhance the performance of α-MOC-CD based broadcasting and routing by using D equivalence classes of CDS. With that, we also apply minimum spanning tree for calculating the shortest path for avoiding the congestion to accomplish proficient broadcasting and routing in wireless networks. Results: The alpha-DEC-MOC-CDS (alpha-D-equivalence classMOC-CDS) shows high network capacity when compared to the existing alpha-MOC-CDS. The proposed method improves the network capacity by using D equivalence classes and also the minimum spanning tree is used to recognize the shortest path. If the number of iterations is increased, the transmission capacity in alpha-DEC-MOC-CDS is 4.07, the medium, routing path length is 6.72 and the average routing path length is 5.73. The comparison result shows that the proposed method achieves better network capacity when compared to the existing system. Conclusion: The findings demonstrate that the alpha-D-equivalence class-MOC-CDS method is presented and suggested that this method high network capacity.Keywords: ConnectedDominating Set(CDS),D-Equivalence Classes, Minimum Routing Cost CDS (α-MOC-CDS), Minimum Support Tree, Shortest Path

An Efficient Bypassing Void Routing Algorithm for Wireless Sensor Network

Since the sensor node’s distribution in a wireless sensor network (WSN) is irregular, geographic routing protocols using the greedy algorithm can cause local minima problem. This problem may fail due to routing voids and lead to failure of data transmission. Based on the virtual coordinate mapping, this paper proposes an efficient bypassing void routing protocol to solve the control packet overhead and transmission delay in routing void of WSN, which is called EBVRPVCM. The basic idea is to transfer the random structure of void edge to a regular one through mapping the coordinates on a virtual circle. In EBVRPVCM, some strategies, executed in different regions, are selected through virtual coordinates to bypass routing void efficiently. The regular edge is established by coordinate mapping that can shorten the average routing path length and decrease the transmission delay. The virtual coordinate mapping is not affected by the real geographic node position, and the control packet overhead can be reduced accordingly. Compared with RGP and GPSR, simulation results demonstrate that EBVRPVCM can successfully find the shortest routing path with higher delivery ratio and less control packet overhead and energy consumption.

AN ADAPTIVE HEURISTIC ALGORITHM WITH THE PROBABILISTIC SAFETY VECTOR FOR FAULT-TOLERANT ROUTING ON THE (n, k)-STAR GRAPH

The (n, k)-star graph is a generalization of the n-star graph. It has better scalability than the n-star graph and holds some good properties compared with the hypercube. This paper focuses on the design of the fault-tolerant routing algorithm for the (n, k)-star graph. We adopt the idea of collecting the limited global information used for routing on the n-star graph to the (n, k)-star graph. In the preliminary version of this paper, we built the probabilistic safety vector (PSV) with modified cycle patterns and developed the routing algorithm to decide the fault-free routing path with the help of PSV. Afterwards, we observed that the routing performance of PSV gets worse as the percentage of fault nodes increases, especially it exceeds 25%. In order to improve the routing performance with more faulty nodes, an adaptive method of threshold assignment for the PSV is also proposed. The performance is judged by the average length of routing paths. Compared with distance first search and safety level, PSV with dynamic threshold gets the best performance in the simulations.

Probability routing strategy for scale-free networks

This study proposes a probability routing strategy for improving traffic capability on scale-free networks. Compared with the shortest path routing strategy depending on central nodes largely and the efficient routing strategy avoiding hub routers as much as possible, the probability routing strategy makes use of hub routers more efficiently, transferring approximate average amount of packs of the whole network. Simulation results indicate that the probability routing strategy has the highest network capacity among the three routing strategies. This strategy provides network capacity that can be more than 30 times higher than that of the shortest path routing strategy and over 50% higher than that of the efficient routing strategy. In addition, the average routing path length of our proposed strategy is over 10% shorter than that of the efficient routing strategy and only about 10% longer than that of the shortest path routing strategy.

Quasi-Kautz Digraphs for Peer-to-Peer Networks

The topological properties of peer-to-peer overlay networks are critical factors that dominate the performance of these systems. Several nonconstant and constant degree interconnection networks have been used as topologies of many peer-to-peer networks. The Kautz digraph is one of these topologies that have many desirable properties. Unlike interconnection networks, peer-to-peer networks need a topology with an arbitrary order and degree, but the Kautz digraph does not possess these properties. In this paper, we propose MOORE: the first effective and practical peer-to-peer network based on the quasi-Kautz digraph with O(logd n) diameter and constant degree under a dynamic environment. The diameter and average routing path length, respectively, are shorter than that of CAN, butterfly, and cube-connected cycle, and are close to that of the de Bruijn and Kautz digraphs. The message cost of node joining and departing operations are at most 2.5d\logd n and (2.5d+1)\logd n, and only d and 2d nodes need to update their routing tables. MOORE can achieve optimal diameter, high performance, good connectivity, and low congestion, evaluated by formal proofs and simulations.

A location‐aware peer‐to‐peer overlay network

AbstractThis work describes a novel location‐aware, self‐organizing, fault‐tolerant peer‐to‐peer (P2P) overlay network, referred to as Laptop. Network locality‐aware considerations are a very important metric for designing a P2P overlay network. Several network proximity schemes have been proposed to enhance the routing efficiency of existing DHT‐based overlay networks. However, these schemes have some drawbacks such as high overlay network and routing table maintenance overhead, or not being completely self‐organizing. As a result, they may result in poor scalability as the number of nodes in the system grows.Laptop constructs a location‐aware overlay network without pre‐determined landmarks and adopts a routing cache scheme to avoid maintaining the routing table periodically. In addition, Laptop significantly reduces the overlay maintenance overhead by making each node maintain only the connectivity between parent and itself. Mathematical analysis and simulations are conducted to evaluate the efficiency, scalability, and robustness of Laptop. Our mathematical analysis shows that the routing path length is bounded by logd N, and the joining and leaving overhead is bounded by d logd N, where N is the number of nodes in the system, and d is the maximum degree of each node on the overlay tree. Our simulation results show that the average latency stretch is 1.6 and the average routing path length is only about three in 10 000 Laptop nodes, and the maximum degree of a node is bounded by 32. Copyright © 2006 John Wiley & Sons, Ltd.

A novel constant degree and constant congestion DHT scheme for peer-to-peer networks

Degree, diameter and congestion are important measures of distributed hash table (DHT) schemes for peer-to-peer networks. Many proposed DHT schemes are based on some traditional interconnection topologies and the Kautz graph is a topology with good properties such as optimal network diameter. In this paper, FissionE, a novel DHT scheme based on the Kautz graph, is proposed. FissionE is the first constant degree and O (log N ) diameter DHT scheme with (1+ o (1))-congestion. FissionE shows that the DHT scheme with constant degree and constant congestion can achieve O (log N ) diameter, which is better than the lower bound Ω ( N 1/d ) conjectured before. The average degree of FissionE is 4 and the diameter is 2*log 2 N , and the average routing path length is about log 2 N , . The average path length of FissionE is shorter than CAN or Koorde with the same degree when the P2P network is large scale.