Fault Tolerant Routing

IntroductionA hypercube is a distributed parallel systemconsisting of 2nidentical processors, each providedwith its own sizable memory and interconnectedwith n neighbors. It has a homogeneoussymmetric structure and has necessarilyrich connectivity. It also has useful topologyin which many other topologies, such asmeshes, rings, trees can be embedded (Saadand Schultz, 1988, 1989).Hypercube structure started to be investigatedin the 1970's and provided a good

In this paper, we propose two cross layer geographic forwarding schemes which address congestion in wireless video sensor networks (VSN) to provide reliable video delivery. The first scheme Load Balanced Reliable Forwarding (LBRF) introduces the notion of local load balancing where a sensor dynamically determines the next hop among the alternative neighbors providing positive advancement towards the sink by considering the balance of their buffer occupancy levels at the time of delivery. LBRF utilizes a modified version of SMAC where the packet structure as well as the operation of SMAC is modified for the accurate monitoring of the buffer occupancy conditions of the neighbors. The second scheme Directional Load Balanced Spreading (DLBS) combines local and direction-based (spatial) load balancing approaches to provide more reliable and faster video delivery by benefiting from the advantages of both approaches. The performance of the forwarding schemes are compared using simulation with two geographic routing schemes where one applies no load balancing and the other applies spatial load balancing. The results show that both LBRF and DLBS provide more reliable video delivery as compared to other schemes, whereas DLBS is more reliable and faster as compared to LBRF. In addition, DLBS provides more energy efficient video delivery in terms of energy expenditure per successfully delivered frame to the sink as compared to LBRF and the other two schemes.

This paper presents a fault-tolerant routing algorithm for mesh-based Networks-on-Chip (NoC) with faulty links. It is a distributed, adaptive and congestion-aware routing algorithm where only two virtual channels are used for both adaptiveness and fault-tolerance. The proposed routing method has a multilevel fault-tolerance capability and therefore it is capable to tolerate more faulty links in more complicated faulty situations with additional hardware costs. The network performance, fault-tolerance capability and ...

Hand-held and palm-held computing devices are becoming increasingly strong. For example, today’s high-end devices have the same (theoretical) computing power and memory capacity as high-end desktops of merely five years ago. Judging from the development of laptops, this trend is likely to continue at an even faster paste in the next few years. These powerful computing devices come equipped with commodity operating systems, such as Linux and Windows CE, which will progressively resemble their desktop OS counterparts as the devices become even more powerful. At the same time, hand-held and palm-held computing devices are being equipped with wireless and cellular communication capabilities, whose bandwidth is gradually approaching standard LAN speeds. Of particular interest to us is wireless communication, due to its hardware broadcast nature, as well as its relative high bandwidth, low cost, and low power consumption when compared to cellular communication.

Wireless Sensor Networks (WSN) based Internet-of-Things (IoT) systems offer high efficient data transmission with enhanced Quality of Service (QoS). A multi-constraint based energy-efficient and fault-tolerant routing algorithm using Fractional Gaussian Firefly Algorithm (FGFA) and Darwinian Chicken Swarm Optimization (DCSO) are presented for performing optimal multipath communication. FGFA is an improved Firefly Algorithm in which the fractional theory and Gaussian function are incorporated to improve the convergence speed with higher efficiency. Likewise, the DCSO is an improved model of CSO based on the survival theory of Darwin to decrease the computation time and improve the convergence by eliminating the local optimal challenges. Initially, the network is clustered and the cluster heads (CH) are chosen optimally by FGFA based on the objective function with multiple QoS constraints. Then the best routing paths are chosen by DCSO through similar objective function with inter-cluster and intra-cluster delay additionally included. The optimal paths are sorted in a hierarchical order from which multiple paths are utilized for data communication. The FGFA+DCSO routing protocol is assessed in NS-2 simulator and the outcomes shown the proficiency of the suggested approach with 6.3% reduced delay, 6% improved throughput, 26.7% minimized energy, 11% increased lifetime, 20% higher PSNR, and hop count reduced by 1.

Currently, some coarse measures like global network latency are used to compare routing protocols. These measures do not provide enough insight of traffic distribution among network nodes in presence of different fault regions. This paper presents a detailed traffic analysis of f-cube routing algorithm achieved by a especially developed tool. Per-node traffic analysis illustrates the traffic hotspots caused by fault regions and provides a great assistance in developing fault tolerant routing algorithms. Based on such detailed information, a simple yet effective improvement of f-cube is suggested. Moreover, the effect of a traffic hotspot on the traffic of neighboring nodes and global performance degradation is investigated. To analyze the per-node traffic, some per-node traffic metrics are introduced and one of them is selected for the rest of work. In an effort to gain deep understanding of the issue of traffic analysis of faulty networks, this paper is the first attempt to investigate per-node traffic around fault regions.

Fault-tolerant routing algorithms are key concerns in Network-on-Chip (NoC) communication. This paper proposes a high performance fault-tolerant routing algorithm based on Fault-Tolerant-Routing (FTR) as a new solution to decrease delay of the messages over the on-chip interconnection mesh networks. The FTR algorithm is a wormhole-switched routing for 2-D mesh networks and has been used for block faults. This algorithm uses virtual channels to pass faulty regions. We have improved the FTR algorithm to decrease message delays in the network without adding new extra virtual channels which led to an Improved-Fault-Tolerant-Algorithm (i-FTR). Moreover, to simulate FTR and i-FTR algorithms, same network conditions namely network size, message length and number of generated messages has been considered. It can be deduced from results that i-FTR performs better compared to FTR algorithm. Furthermore, results show that the interconnection network of NoC which has been used for i-FTR can deal with higher message rates and can tolerate higher traffic loads.

Congestion is a challenging problem in wireless sensor networks, which exacerbates with the high volume of data traffic imposed by video applications such as video surveillance and target tracking. Deployment of multiple sinks is a candidate solution for congestion and is also promising in terms of reliability and energy-efficiency. In order to gain the maximum benefit from multiple sinks, it is essential to distribute the load among them evenly. In this paper, we propose a cross layer geographic forwarding scheme MLBRF (Multi-Sink Load Balanced Reliable Forwarding) which aims to provide reliable and energy efficient video delivery in a multi-sinked sensor network for target tracking. In order to provide load balancing among the sinks, MLBRF proposes a sink selection mechanism based on fuzzy logic for the frame forwarding which evaluates the traffic density in the direction of each sink by combining two dynamic criteria which are the number of contenders and the buffer occupancy levels in the neighborhood with the static distance criterion. The performance of the fuzzy sink selection mechanism is compared using simulation with various sink selection mechanisms. The results show that MLBRF gains the maximum benefit from deploying multiple sinks in terms of reliability, latency and energy efficiency by using the proposed fuzzy sink selection mechanism.

Hand-held and palm-held computing devices are becoming increasingly strong. For example, today’s high-end devices have the same (theoretical) computing power and memory capacity as high-end desktops of merely five years ago. Judging from the development of laptops, this trend is likely to continue at an even faster paste in the next few years. These powerful computing devices come equipped with commodity operating systems, such as Linux and Windows CE, which will progressively resemble their desktop OS counterparts as the devices become even more powerful. At the same time, hand-held and palm-held computing devices are being equipped with wireless and cellular communication capabilities, whose bandwidth is gradually approaching standard LAN speeds. Of particular interest to us is wireless communication, due to its hardware broadcast nature, as well as its relative high bandwidth, low cost, and low power consumption when compared to cellular communication.

With nowadays popularity of large-scale parallel computers, Multiprocessors System-on-Chip (MP-SoCs), multicomputers, cluster computers and peer-to-peer communication networks, fault-tolerant routing becomes an important issue in developing these systems. Fault-tolerant routing algorithms in such systems aim at providing continuous operations in the presence of one or more failures by allowing the graceful degradation of system. The Software-Based fault-tolerant routing scheme has been suggested as an efficient routing algorithm to preserve both communication performance and fault-tolerant demands in parallel computer systems. To study network performance, a number of different analytical models for fault-free routing algorithms have been proposed in the past literature. However, there has not been reported any similar analytical model of fault-tolerant routing in the presence of faulty components. This paper presents a new analytical modeling approach for determining the effects of...

Congestion is a challenging problem in wireless sensor networks, which exacerbates with the high volume of data traffic imposed by video applications such as video surveillance and target tracking. Deployment of multiple sinks is a candidate solution for congestion and is also promising in terms of reliability and energy-efficiency. In order to gain the maximum benefit from multiple sinks, it is essential to distribute the load among them evenly. In this paper, we propose a cross layer geographic forwarding scheme MLBRF (Multi-SinkLoadBalanced Reliable Forwarding) which aims to provide reliable and energy efficient video delivery in a multi-sinked sensor network for target tracking. In order to provide load balancing among the sinks, MLBRF proposes a sink selection mechanism based on fuzzy logic for the frame forwarding which evaluates the traffic density in the direction of each sink by combining two dynamic criteria which are the number of contenders and the buffer occupancy levels in the neighborhood with the static distance criterion. The performance of the fuzzy sink selection mechanism is compared using simulation with various sink selection mechanisms. The results show that MLBRF gains the maximum benefit from deploying multiple sinks in terms of reliability, latency and energy efficiency by using the proposed fuzzy sink selection mechanism.

We consider the problem of computing the best swap edges of a shortest-path tree T r rooted in r. That is, given a single link failure: if the path is not affected by the failed link, then the message will be delivered through that path; otherwise, we want to guarantee that, when the message reaches the edge (u,v) where the failure has occurred, the message will then be re-routed using the computed swap edge. There exist highly efficient serial solutions for the problem, but unfortunately because of the structures they use, there is no known (nor foreseeable) efficient distributed implementation for them. A distributed protocol exists only for finding swap edges, not necessarily optimal ones. In [6], distributed solutions to compute the swap edge that minimizes the distance from u to r have been presented. In contrast, in this paper we focus on selecting, efficiently and distributively, the best swap edge according to an objective function suggested in [13]: we choose the swap edge ...