Routing Tasks Research Articles

Energy Efficient Clustering in Wireless SensorNetworks Using Fuzzy Approach to Improve LEACH Protocol

The most important consideration in designing protocols for wireless sensor networks is the energy constraint of nodes because in most cases battery recharging is inconvenient or impossible. Therefore, many researches have been done to overcome this demerit. Clustering is one of the main approaches in designing scalable and energy-efficient protocols for wireless sensor networks. The cluster heads take the task of data aggregation and data routing to decrease the amount of communication and this prolongs the network lifetime. LEACH protocol is one of the famous of them. In this paper, we proposed a novel scheme to investigate the cluster, the Fuzzy Logic Cluster Leach Protocol (FUZZY-LEACH), which uses Fuzzy Logic Inference System (FIS) in the cluster process. We demonstrate that using multiple parameters in cluster reduces energy consumption. We compare our technique with the LEACH protocol to show that using a multi parameter FIS enhances the network lifetime significantly. Simulation results demonstrate that the network lifetime achieved by the proposed method could be increased by nearly 28.5% more than that obtained by LEACH protocol in  scenario, and by nearly 26.4% more than that LEACH protocol in  scenario.

JOKER: A Novel Opportunistic Routing Protocol

The increase in multimedia services has put energy saving on the top of current demands for mobile devices. Unfortunately, batteries’ lifetime has not been as extended as it would be desirable. For that reason, reducing energy consumption in every task performed by these devices is crucial. In this work, a novel opportunistic routing protocol, called JOKER, is introduced. This proposal presents novelties in both the candidate selection and coordination phases, which permit increasing the performance of the network supporting multimedia traffic as well as enhancing the nodes’ energy efficiency. JOKER is compared in different-nature test-benches with BATMAN routing protocol, showing its superiority in supporting a demanding service such as video-streaming in terms of QoE, while achieving a power draining reduction in routing tasks.

Community Detection Using Inter Contact Time and Social Characteristics Based Single Copy Routing in Delay Tolerant Networks

Delay Tolerant Networks (DTNs) where the node connectivity is opportunistic and end-to-end path between any pair of source and destination is not guaranteed most of the time. Hence the messages are transferred from source to destination via intermediate nodes on hop to hop basis using store-carry-forward paradigm. Due to quick advancement in hand held devices such as smart phone and laptop with support of wireless communication interface carried by human being, it is possible in coming days to use DTNs for message dissemination without setting up infrastructure. The routing task becomes challenging in DTNs due to intermittent network connectivity and the connection opportunity arises only when node comes in transmission range of each other. The performance of the routing protocols depend on the selection of appropriate relay node which can deliver the message to final destination in case of source and destination do not meet at all. Many social characteristics are exhibited by the human being like friendship, community, similarity and centrality which can be exploited by the routing protocol in order to take the forwarding decisions. Literature shows that by using these characteristics, the performance of DTN routing protocols have been improved in terms of delivery probability. The existing routing schemes used community detection using aggregated contact duration and contact frequency which does not change over the time period. We propose community detection through Inter Contact Time (ICT) between node pair using power law distribution where the members of community are added and removed dynamically. We also considered single copy of each message in entire network to reduce the network overhead. The proposed routing protocol named Social Based Single Copy Routing (SBSCR) selects the suitable relay node from the community members only based on the social metrics such as similarity and friendship together. ICTs show power law nature in human mobility which is used to detect the community structure at each node. A node maintains its own community and social metrics such as similarity and friendship with other nodes. Whenever node has to select the relay node then it selects from its community with higher value of social metric. The simulations are conducted using ONE simulator on the real traces of campus and conference environments. SBSCR is compared with existing schemes and results show that it outperforms in terms of delivery probability and delivery delay with comparable overhead ratio.

Computational Optimization of Placement and Routing using Genetic Algorithm

In the VLSI chip designing process, Floor-planning is one of the vital stages which in turn have Placement and Routing tasks. This paper concentrates on solving the problems which occur in VLSI floor planning and gives an overview of placement and routing problems in ICs. This approach depends on recursive optimization prototypes with redefined algorithm. The searching for best solutions is carried out by Genetic Algorithm (GA) on each iteration since these algorithms is already known and proven to solve similar type of problems. GA has been tested randomly and is simulated. By conducting experiments on GA we can realize optimized solutions for the above said problems.

Developing a Distributed Software Defined Networking Testbed for IoT

The rapid proliferation of the Internet of Things (IoT) has led to growth in the ad-hoc networking scenario. With the recent upcoming technologies of network programmability like SDN may be effectively integrated to create a communication platform. In this work, we present the details of our preliminary study of how to determine the effectiveness of an approach to build a cluster network using Software-Defined Networking (SDN). We will provide an overview of optimum path routing protocol with cluster interaction. Our proposed scheme is a starting point for some experiments providing perspective over SDN deployment in a cluster environment for IoT. With this aim in mind, we propose a routing protocol that manages routing tasks over Cluster-SDN. By using network virtualization and OpenFlow technologies to generate virtual nodes, we simulate a prototype system controlled by SDN. Our designed testbed, is a real openflow protocol evaluation environment comprising networks and applications, which provide flexible control of framework support for large scale experiments.

Dynamic greedy routing in overlay networks using virtual coordinates from the hyperbolic plane

AbstractGreedy routing algorithms based on virtual coordinates have attracted considerable interest in recent years. Those based on coordinates taken from the hyperbolic plane have interesting theoretical scalability properties. However, their scalability and reliability are yet to be ensured when applied to large‐scale dynamic networks. In this paper, we propose a scalable and reliable solution for creating and managing dynamic overlay networks where nodes have hyperbolic coordinates. In this context, our solution provides a greedy routing algorithm based on the hyperbolic distance. To cope with network dynamics, we have defined two methods for avoiding temporary local minima and one method for maintaining the greedy embedding over time. Through analysis, we evaluate the complexity costs of our solution. Through simulations, we assess the scalability of our solution on static networks and its reliability on dynamic networks. Results show that using our solution based on hyperbolic geometry provides scalability and reliability to both addressing and routing tasks in dynamic overlay networks. Copyright © 2015 John Wiley & Sons, Ltd.

Learning automata based multipath multicasting in cognitive radio networks

Cognitive radio networks (CRNs) have emerged as a promising solution to the problem of spectrum under utilization and artificial radio spectrum scarcity. The paradigm of dynamic spectrum access allows a secondary network comprising of secondary users (SUs) to coexist with a primary network comprising of licensed primary users (PUs) subject to the condition that SUs do not cause any interference to the primary network. Since it is necessary for SUs to avoid any interference to the primary network, PU activity precludes attempts of SUs to access the licensed spectrum and forces frequent channel switching for SUs. This dynamic nature of CRNs, coupled with the possibility that an SU may not share a common channel with all its neighbors, makes the task of multicast routing especially challenging. In this work, we have proposed a novel multipath on-demand multicast routing protocol for CRNs. The approach of multipath routing, although commonly used in unicast routing, has not been explored for multicasting earlier. Motivated by the fact that CRNs have highly dynamic conditions, whose parameters are often unknown, the multicast routing problem is modeled in the reinforcement learning based framework of learning automata. Simulation results demonstrate that the approach of multipath multicasting is feasible, with our proposed protocol showing a superior performance to a baseline state-of-the-art CRN multicasting protocol.

Integrated tasks assignment and routing for the estimation of the optimal number of AGVS

A fundamental problem in the management of an automated guided vehicle system (AGVS) is the determination of the load to be transported and the vehicle to transport it. The time for the loading and unloading of pallets must be specified as soon as possible. Typical objectives are minimization of travel times and costs by the reduction of the number of vehicles required to fulfill a given transportation order. This article presents a methodology for the estimation the minimum number of AGVs (considering all the available ones at the shop floor level) required to execute a given transportation order within a specific time-window. A comparison is made between the algorithms Shortest Job First and meta-heuristic Tabu Search (applied to an initial solution) for a task assignment. An enhanced Dijkstra algorithm is used for the conflict-free routing task. The number of vehicles is estimated so as to provide an efficient distribution of tasks and reduce the operational costs of the materials handling system. Simulation results of two typical industrial warehouse shop floor scenarios are provided. Although the study focuses on pre-planning of order fulfillment of materials handling, the proposed methodology can also be utilized as an important tool for investment analysis of the warehouse layout design and for estimating the ideal number of AGVs.

Stabilization Algorithms for Automatic Control of the Trajectory Movement of Quadcopter

The article considers an automatic quadcopter routing task. The quadcopter is an unmanned aerial vehicle (UAV), which has four engines. Currently, such already widely used vehicles are controlled, mainly, from the operator’s control panel. A relevant task is to develop a quadcopter control system that enables an autonomous flight. The aim of this paper is to study the possibility for solving this problem using an algorithm of the stabilization and trajectory control. A mathematical model of the quadrocopter is the fairly complicated non-linear system, which can be obtained by using the Matlab Simulink and Universal Mechanism software systems simultaneously. Comparison of the simulation results in two software packages, i.e. Matlab wherein the nonlinear system of equations is modeled and UM wherein the flight path and other parameters are calculated according to transmitted forces and moments may prove correctness of the model used. Synthesis of controllers for the orientation and stabilization subsystem and trajectory control subsystem, is performed on traditional principles, in particular using the PID controllers and method based on Lyapunov functions known in the literature as backstepping. The most appropriate controls are selected by comparing the simulation results. Responses to the stepped impacts and to tracking the given paths have been simulated. It has been found that the flight path of a quadcopter almost coincides with designated routing, changes of coordinates for the quadcopter mass center of two controllers under comparison are almost the same, but a deviation range of the angular position for the controller backstepping is much smaller than that of for the PID controller.

Evaluation of Dynamic Ambulance Routing for the Transportation of Patients with Acute Coronary Syndrome in Saint-petersburg

Abstract Effective treatment of acute coronary syndrome (ACS) patients depends on the transportation time to a hospital. But selection of an optimal route and target hospital for an ambulance within a large city is a complex problem. It requires taking into account the dynamical nature of an urban environment. Such dynamic factors as traffic flow, changing road graph, population mobility, and hospital capabilities are sources of uncertainty in decision making on hospitalization, and eventually they influence the functioning quality of emergency medical services (EMS) in a city. This work is devoted to the analysis of this problem for the city of Saint-Petersburg (Russia) with the use of statistical data, public geographic information services (OpenStreetMap), and real-time data on traffic flow (Yandex.Maps). It is shown that dynamic traffic conditions influence selection of a hospital and have to be considered within the task of ambulance routing. The results may be applied in order to design a more efficient EMS decision support system for ambulance personnel and dispatchers.

Exploring Routing Security in Ad Hoc Networks

Ad Hoc networks are the ones don’t use any network axillary element for routing, but participated nodes in these networks have task of network routing. Security in Ad hoc networks has a particular condition, because besides problems such as existed problems in wire networks, we face with problems such as simple hearing and information changing in transferring, possibility of people impersonation or damage routing operations, non-possibility of using coded key distribution infrastructures and so on. One of the most important security cases in ad hoc networks is providing a secured routing algorithm in these networks. It has been tried in recent years to provide a secured routing algorithm in ad hoc networks, amongst, there are protocols such as ARAN, SAODA, SRP, Ariadne, SEAD, etc. but each one has its particular problems. Moreover, lack of an acceptable algorithm both according to security and network efficiency is felt.

An enhanced location-free Greedy Forward algorithm with hole bypass capability in wireless sensor networks

Greedy Forward is a technique for data routing in Wireless Sensor Networks (WSNs) in which data packets are forwarded to the node that is geographically closer to the destination node. Two main concerns can be found in routing algorithms based on this technique: first, it requires all sensor nodes to know their physical location. Second, this kind of algorithm does not work in cases when a node is located in a network ’hole’, i.e., the node does not have any neighbor closer to the destination node. In this work, we propose a new Greedy Forward algorithm that can be used in routing protocols for WSNs that does not require localization of the nodes and also is able to deal with nodes located near network holes. Differently from current greedy forward algorithms, our approach uses only the Received Signal Strength Indicator (RSSI) of exchanged packets. Based on this observation, we propose the RSSR (Received Signal Strength Routing) algorithm with two variants: RSSR Election and RSSR Selection. In the RSSR Election, the next hop is dynamically elected and no packets are required for the routing task. In the RSSR Selection, neighbors exchange packets with RSSI information and the next hop of the packet is then selected from a routing table. Then, we present a novel technique for dealing with network holes even when the physical location of the nodes is unknown. This technique improves the reliability and applicability of the proposed schemes in most WSN scenarios. Our results indicate clearly that the proposed algorithms have all the benefits of a greedy forward algorithm but with better performance, better packet delivery rate and without requiring position information.

Energy-Efficient Adaptive Routing and Context-Aware Lifetime Maximization in Wireless Sensor Networks

We design and implement a Bezier-based multipath routing algorithm that allows a given source node to send samples of data to a given sink node in large scale sensor networks. Multipath routing can distribute the energy load onto the multiple routes and thus increase the lifetime and quality of the network. It is important to stress the fact that evenly regulating the routing task among the more nodes of the network can also protect a node from failure considering that a node with heavy duty is likely to deplete its power quickly. On the contrary, all the traffic would be shipped along the shortest path routing, corresponding to the heavily congested path case, which in turn leads to overload of the nodes along the optimal routes between the sink and source pair and finally shortens the lifetime of the network. Also, multipath routing can increase end-to-end throughput and provide load balancing. Our view is that minimizing energy consumption while meeting acceptable latency for applications can lead to significant power savings. Our simulation results demonstrate that Bezier-based multipath routing approach significantly outperforms previous SWEEP, Tributaries and Deltas, and the shortest path approaches in terms of lifetime and latency.

Approach to a Message Routing for Wireless Mesh Networks with a Rapidly Changing Topology

A development of the major part of economy branches nowadays is provided through the wide scale adaptation of social networks, which are capable of connecting resources of both legal persons and physical persons. That trend requires a developed infrastructure based on new solutions for the aggregation of mobile devices in a so called wireless mesh networks. One of the central tasks of that aggregation is message routing in networks with a rapidly changing topology. The purpose of the presented paper is an attempt to analyze the main message routing algorithms in wireless networks with respect to mesh networks with rapidly changing topology, and to make recommendations for their improvement and development. As the primary reason, which prevents the achievement of a quality routing in networks with a rapidly changing topology, the instability of links between network nodes is considered. For the assessment of quality of channels between nodes, the implementation of following parameters is proposed: package transmission delay, available network capacity and time of life of a communication channel, which can be easily adjusted by empirically-selectable threshold values. For the solution of the task of message routing of wireless mesh networks with a rapidly changing topology, a criteria is proposed which implements weighted values of proposed parameters. The selection of threshold values of parameters and their weights in order to calculate criterion expression is the important part of a network design, and depends on its expected work characteristics.

Comparative Study of Dominant Routing Protocols in Ad Hoc Networks

An network is an autonomous self-organized wireless network. It consists of a collection of wireless nodes in which the communication paradigm is decentralized. The term ad hoc refers to the lack of any preexisting communication infrastructure such as routers in wired networks or access points in the traditional wireless networks. Instead, each node participates in routing by forwarding data for other nodes, so the determination of which nodes forward data is made dynamically on the basis of network connectivity. The network is an autonomous system in which mobile hosts connected by wireless links are free to move randomly and often act as routers at the same time. As a result, the routing task in such type of networks introduces several types of challenges which were never apparent in the traditional infrastructure-based networks. The main objective of this study is to investigate the routing problem in wireless networks. More specifically, the performance of the different routing protocols which are dominantly adopted in such types of network environments will be examined. A simulation model with MAC and physical layer models, based on the simulation tool ns-2, was used in studying the behavior of two different protocols, namely, Ad Hoc On-Demand Distance Vector Routing (AODV), and DestinationSequenced Distance-Vector Routing (DSDV). Two performance metrics were used to establish a comparison between these routing algorithms: Average End-to-End Delay, and Packet Delivery Ratio. Simulation results showed that On-Demand routing protocol, AODV, provides a higher Packet Delivery Ratio. However, Table-Driven routing protocol, DSDV outperformed AODV in minimizing the Endto-End Delay.

Optimal answerer ranking for new questions in community question answering

Community question answering (CQA) services that enable users to ask and answer questions have become popular on the internet. However, lots of new questions usually cannot be resolved by appropriate answerers effectively. To address this question routing task, in this paper, we treat it as a ranking problem and rank the potential answerers by the probability that they are able to solve the given new question. We utilize tensor model and topic model simultaneously to extract latent semantic relations among asker, question and answerer. Then, we propose a learning procedure based on the above models to get optimal ranking of answerers for new questions by optimizing the multi-class AUC (Area Under the ROC Curve). Experimental results on two real-world CQA datasets show that the proposed method is able to predict appropriate answerers for new questions and outperforms other state-of-the-art approaches.

Improve Reliability and Load Balancing of using ACO Mechanism in Ad hoc Network

Ad hoc network consist of autonomous self-organized nodes. Nodes use a wireless medium for communication. Thus two nodes can communicate directly if and only if they are within each other’s transmission radius. In Ad hoc networks, routing not only has to be fast and efficient, but also adaptive to the changes in the network topology; otherwise, the performance may be severely degraded. In a routing task, a message is sent from a source to a destination node in a given network. Two nodes normally communicate via other nodes in a multi-hop fashion. In this paper we analyze an ACO (Ant Colony Optimization) based routing algorithm with AOMDV protocol for load balancing to route packets through shorter and feasible routes. Each ant while moving towards destination collects information about address of each visited node of the followed path means the pheromones values. During backward travel, local network traffic model and routing table is modified by ant based on the goodness of the followed path. The performance of ACO with AOMDV has provides the possibility of light load traffic routes that is not possible to find in normal AOMDV routing protocol and provides the efficient load balancing on the basis of high and low pheromones value. Simulation results shows that the proposed ACO based routing protocol gives performance improvement over other routing protocol by continuously checking for better paths in the network with less overhead. Index Terms Routing, Ad hoc network, AOMDV, ACO, Load balancing

A centrality-based topology control protocol for wireless mesh networks

Nodes in wireless multi-hop networks establish links with their neighbors, which are used for data transmission. In general, in this kind of networks every node has the possibility of acting as a router, forwarding the received packets when they are not the final destination of the carried data. Due to the routing protocol procedures, when the network is quite dense the overload added by the routing management messages can be very high. To reduce the effects of this overload a topology control mechanism can be used, which can be implemented using different techniques. One of these techniques consists of enabling or disabling the routing functionality in every node. Many advantages result from selecting just a subset of nodes for routing tasks: reduction of collisions, protocol overhead, interference and energy consumption, better network organization and scalability. In this paper, a new protocol for topology control in wireless mesh networks is proposed. The protocol is based on the centrality metrics developed by social network analysts. Our target network is a wireless mesh network created by user hand-held devices. For this kind of networks, we aim to construct a connected dominating set that includes the most central nodes. The resulting performance using the three most common centrality measures (degree, closeness and betweenness) is evaluated. As we are working with dynamic and decentralized networks, a distributed implementation is also proposed and evaluated. Some simulations have been carried out to analyze the benefits of the proposed mechanism when reactive or proactive routing protocols are used. The results confirm that the use of the topology control contributes to a better network performance.

Robust routing and channel allocation in multi-hop cognitive radio networks

Jointly consider routing and spectrum selection is essentially and necessary in multi-hop cognitive radio networks. System cost and throughput are commonly used to evaluate performance of routing and spectrum selection schemes. Traditional methods mostly translate these metrics into a single objective function, and corresponding weights are allocated to each metric representing impact on the entire network performance. Optimal solutions of these approaches are sensitive to the weight settings which are usually hard to appropriately chosen. In this work, the task of routing and channel allocation is modeled as a two-objective optimization problem. Two conflicting metric functions system total throughput and total cost are optimized simultaneously, and a novel memetic algorithm which adopts a new neighborhood search procedure is proposed to solve this problem. Incorporated with robustness consideration on routing, a new robustness metric is also presented to work as a decision mechanism to ensure the robustness of the entire network. The aim of this task is to find the best compromise routing and channel allocation scheme on system throughput, cost and robustness among the feasible solution set. Simulation results demonstrate that the optimal solution set obtained by the memetic algorithm can clearly show the conflicting relationship of the system cost and throughput when choosing different routing and channel selection schemes. The best solution made by the additional robustness metric among these solutions can achieve the best performance of the cognitive radio network.

A design assembly framework for FPGA back-end acceleration

There are well known cases where FPGAs provide high performance within a modest power budget, yet unlike conventional desktop solutions, they are oftentimes associated with long wait times before a device configuration is generated. Such long wait times constitute a bottleneck limiting the number of compilation runs performed in a day; thus limiting to FPGA adaptation in modern computing platforms. This work presents an FPGA development paradigm that exploits logic variance and hierarchy as a means to increase FPGA productivity. The practical tasks of logic partitioning, placement and routing are examined and a resulting assembly framework, Quick Flow (qFlow), is implemented. Fifteen International Workshop on Logic and Synthesis (IWLS) 2005 benchmark designs and five large designs are used to evaluate qFlow. Experiments show up to 10× speed-ups using the proposed paradigm compared to vendor tool flows.