Dynamic Routing Mechanism Research Articles

On Enhancing Network Dynamic Adaptability for Compressive Sensing in WSNs

Both energy efficiency and network dynamic adaptability are crucial research issues in wireless sensor networks (WSNs). Compressive sensing has been widely adopted in WSNs for efficient data gathering. Random walk is a typical dynamic routing mechanism. Integrating compressive sensing with random walk offers the opportunity to achieve both efficiency and dynamic adaptability. However, there are still many problems in the existing schemes, such as semi-dynamic routing (which contains both dynamic and static routing), non-uniform sampling and relying on global coordinate information. In order to address these problems, we propose a dual random walk based compressive sensing. First, we design a dual random walk, which is a directed random walk but does not depend on the coordinate information of each node, and it also achieves a uniform sampling. Then, we construct a dynamic compressive sensing data gathering scheme based on the dual random walk, which effectively enhances the network dynamic adaptability. Both theoretical analysis and experimental evaluation are conducted. The experimental evaluation results demonstrate that it outperforms the most closely related work.

Dynamic clustering approach with ACO-based mobile sink for data collection in WSNs

Enhancing the network lifetime of wireless sensor networks is an essential task. It involves sensor deployment, cluster formation, routing, and effective utilization of battery units. Clustering and routing are important techniques for adequate enhancement of the network lifetime. Since the existing clustering and routing approaches have high message overhead due to forwarding collected data to sinks or the base station, it creates premature death of sensors and hot-spot issues. The objective of this study is to design a dynamic clustering and optimal routing mechanism for data collection in order to enhance the network lifetime. A new dynamic clustering approach is proposed to prevent premature sensor death and avoid the hot spot problem. In addition, an Ant Colony Optimization (ACO) technique is adopted for effective path selection of mobile sinks. The proposed algorithm is compared with existing routing methodologies, such as LEACH, GA, and PSO. The simulation results show that the proposed cluster head selection algorithm with ACO-based MDC enhances the sensor network lifetime significantly.

A hop-by-hop dynamic distributed multipath routing mechanism for link state network

High reliability is always pursued by network designers, operators and users. Multipath routing can provide multiple paths for transmission and failover, and is considered to be effective in the improvement of network reliability.Existing multipath routing algorithms are tailored to find as many paths as possible and to guarantee loop-freeness, with their computation or communication overhead often overlooked. For example, a router either constructs multiple shortest path trees, or exchanges information with its neighbors for every destination, witnessing a particularly high cost when connecting with a large number of neighbors. Moreover, these algorithms typically perform a recomputation from scratch whenever the network state changes, leading to further resource scarcity.We propose an algorithm, DMPA (dynamic multipath algorithm), for a router in a link-state network to compute multiple next-hops for each destination. The algorithm constructs one single shortest path tree based on ordinary network link states, and dynamically adjusts it in response to network state changes, so the sets of next-hops can be efficiently computed and incrementally updated. At the same time, DMPA guarantees loop-freeness of the induced routing path by implicitly maintaining a partial order of the routers underpinning it. And also, we present a further extension of DMPA (DMPA-e) by incorporating hop count, a topology dependent metric.We evaluate the proposed algorithms and compare them with several latest multipath algorithms, using some real and inferred ISP topologies, and also a set of synthetic topologies. Our results show that our proposed algorithms can provide good reliability and fast recovery for the network with very low overhead.

Dynamicity of the scout bee phase for an Artificial Bee Colony for optimized cluster head and network parameters for energy efficient sensor routing

Data transmitted to the base station from the sensor node by selecting an optimal cluster head is a massive challenge subjected to the routing protocol, in the case of the wireless sensor network. An energy efficient clustering method, depending on the Artificial Bee Colony (ABC) algorithm and the Fractional Artificial Bee Colony (FABC) algorithm, has a propensity to maximize the energy of the network and life time of nodes by the optimal cluster head selection (CHS). When conveying data, an ABC-Dynamic Scout bee algorithm is presented that multiplies the scout bee production to enlarge the number of alive nodes and the of CH energy. An assessment among the performances of the implemented ABC-based Dynamic Scout bee algorithm routing mechanism in opposition to that of ABC-based CHS and FABC-based CHS routing is done. The experimental outcome demonstrates that the implemented method increases the quantity of alive nodes with 25% of maximum energy for the normalized network compared with conventional protocols.

Dynamic Cloudlet-Assisted Energy-Saving Routing Mechanism for Mobile Ad Hoc Networks

In mobile ad hoc networks (MANETs), if mobile devices frequently leave or join the overlay of MANETs, the communication links between mobile devices or between mobile devices and cloud will lose or reestablish; for searching and routing the needed cloud services again, more energy will be consumed. 5G is the fifth generation mobile communication technology, and fog computing is defined as a distributed computing infrastructure that is able to handle billions of Internet-connected devices. Therefore, combining fog computing with 5G, we present a novel and effective dynamic cloudlet-assisted routing mechanism (DCRM) for MANETs to solve the energy-saving problem of link breakages. First, for every mobile device in MANETs, we build a temporary file to record its identity and route information in a certain time. Moreover, as a key promising technology of 5G, device-to-device is used as the communication way between mobile devices, because it can enhance the communication ability and the information sharing ability between mobile devices. Second, cloudlets can be considered as small data centers, and we set the sharing relation table and the cooperation mechanism between cloudlets. Then, relying on these, mobile devices can quickly route and search the requested services regardless of the frequent movement of mobile devices in MANETs. The experimental results show that DCRM can save more time and several times more energy, and display more advantages than the network model without the proposed mechanism in many ways, consequently enable cloud to provide services that are more realistic for the future mobile network applications.

Design and implementation of a low-cost prototype system for continuous monitoring of electric fields generated by mobile base stations in the 850 MHz and 1900 MHz frequency bands

This paper describes the development of a scalable, autonomous and inexpensive monitoring system of electric fields generated by mobile phone base stations in the 850 MHz and 1900 MHz frequency bands, in Peru. The developed system is scalable because it consists of a ZigBee wireless network with electric field strength sensor and repeater nodes in a mesh topology with a dynamic routing mechanism. Sensor and repeater nodes are autonomous because they get their power from a small photovoltaic system. All electronic circuits were developed using low-cost technology. To manage the system elements and to store the information captured by the sensors, a web platform was developed. Tests in laboratory and field were performed to assess the accuracy of the sensor node. For this, a calibrated isotropic Narda SRM 3000 electric field meter was used. The results were very satisfactory for 1900 MHz frequency band but not for 850 MHz; some recommendations are given to improve the accuracy in the latter case. The performance of the sensor node's photovoltaic system was also assessed through the monitoring of the continuity of the system operation over time. It was verified that the sensor node was kept operating continuously without failures during a three-month test.

Research on dynamic routing mechanisms in wireless sensor networks.

WirelessHART is the most widely applied standard in wireless sensor networks nowadays. However, it does not provide any dynamic routing mechanism, which is important for the reliability and robustness of the wireless network applications. In this paper, a collection tree protocol based, dynamic routing mechanism was proposed for WirelessHART network. The dynamic routing mechanism was evaluated through several simulation experiments in three aspects: time for generating the topology, link quality, and stability of network. Besides, the data transmission efficiency of this routing mechanism was analyzed. The simulation and evaluation results show that this mechanism can act as a dynamic routing mechanism for the TDMA-based wireless sensor network.

Agent-based Simulation Testbed for On-demand Mobility Services

New markets for personalized and efficient transport are creating a need for on-demand mobility services. To rigorously analyse new control mechanisms for these services, we introduce an open-source agent-based simulation testbed that allows users to eva- luate the performance of multi-agent, on-demand transport schemes. In particular, our testbed provides a framework to compare both centralized and decentralized, static and dynamic passenger allocation and vehicle routing mechanisms under various con- ditions; including varying vehicle fleets, road network topologies and passenger demands. Our testbed supports all stages of the experimental process; from the implementation of control mechanisms and the definition of experiment scenarios, through to simu- lation execution, analysis, and interpretation of results. Ultimately, the testbed accelerates the development of control mechanisms for emerging on-demand mobility services and facilitates their comparison using well-defined benchmarks.

Fairness Based Dynamic Routing Technique (FsBDRT) in Wireless Mesh Network

This study aims to present a joint solution of routing and fair resource allocation which in terms of OSI layered architecture belongs to two different layers but both cannot be considered as individual problems. The routing problem in WMNs is concerned with finding “good and optimum path” from source to destination. The objective of this research is to provide a new dynamic technique for efficient and reliable self-path utilization and provision of better and efficient way of handling issues of load balancing and congestion control in WMN. For fairness of resource allocation, this study presents the method of load balancing, where multiple paths to destination are used to distribute the traffic. These multiple paths are ultimately figured out using dynamic routing, which not only improves performance but also provides reliability, especially in presence of lossy channels. In this study we propose a Fairness Based Dynamic Routing Technique (FsBDRT) a dynamic routing mechanism to adapt an optimal path, as well as identification of lossy channel becomes due to congestion.

A Dynamic Routing Mechanism Based on Collection Tree Protocol in Industrial Wireless Sensor Networks

无线HART(Highway Addressable Remote Transducer)是当前工业无线传感器网络中应用最为广泛的协议，但无线HART没有提供动态路由机制以满足对工业无线网络应用至关重要的稳定性和鲁棒性。该文在无线HART协议基础上，提出一个基于收集树协议的可应用于工业无线传感器网络的动态路由机制。它占用时分多址(TDMA)超帧中的前几个时间片来产生和维护网络拓扑。通过仿真实验从3个方面对该动态路由机制进行了评估：拓扑生成时间，链路质量及网络拓扑的稳定性。仿真和评估结果表明该动态路由机制可以在基于TDMA的工业无线传感器网络中应用。

Analyzing the Effect of Varying CBR on AODV, DSR, IERP Routing Protocols in MANET

Mobile Ad Hoc Networks (MANET) are wireless networks which do not require any infrastructure support for transferring data packet between two nodes. Mobile ad-hoc network have the attributes such as wireless connection, continuously changing topology, distributed operation and ease of deployment. The mobile nodes perform both as a host and a router forwarding packets to other nodes. Routing in these networks is highly complex. It can be used for various applications areas as sensor applications, disaster management, conferences, rescue operations, military communications, hybrid wireless network architectures and wireless mesh networks and many more. Traditional routing mechanism and protocol of wired network are inapplicable to ad-hoc networks which initiated the need of a dynamic routing mechanism in ad-hoc network. This paper evaluates the performance of AODV, DSR (Reactive) and IERP (Hybrid) routing protocols with respect to varying Constant Bit Rate (CBR). A detailed simulation has been carried out in QualNet Simulator 6.1. The performance analysis is based on different network metrics such as Average End to End delay, Throughput, Average Jitter, Packet Delivery Ratio. Keywords: AODV, DSR, IERP, Mobile Ad-hoc networks, QualNet 6.1

Switching Neuronal Inputs by Differential Modulations of Gamma-Band Phase-Coherence

Receptive fields (RFs) of cortical sensory neurons increase in size along consecutive processing stages. When multiple stimuli are present in a large visual RF, a neuron typically responds to an attended stimulus as if only that stimulus were present. However, the mechanism by which a neuron selectively responds to a subset of its inputs while discarding all others is unknown. Here, we show that neurons can switch between subsets of their afferent inputs by highly specific modulations of interareal gamma-band phase-coherence (PC). We measured local field potentials, single- and multi-unit activity in two male macaque monkeys (Macaca mulatta) performing an attention task. Two small stimuli were placed on a screen; the stimuli were driving separate local V1 populations, while both were driving the same local V4 population. In each trial, we cued one of the two stimuli to be attended. We found that gamma-band PC of the local V4 population with multiple subpopulations of its V1 input was differentially modulated. It was high with the input subpopulation representing the attended stimulus, while simultaneously it was very low between the same V4 population and the other input-providing subpopulation representing the irrelevant stimulus. These differential modulations, which depend on stimulus relevance, were also found in the locking of spikes from V4 neurons to the gamma-band oscillations of the V1 input subpopulations. This rapid, highly specific interareal locking provides neurons with a powerful dynamic routing mechanism to select and process only the currently relevant signals.

Application of MIH for the lightweight deployment of LTE-advanced systems through mobile relaying

In a conventional cellular network end users connect directly to a Base Station (BS). Mobile relaying allows establishing an indirect two-hop link between the end user, called Mobile Node (MN), and the BS through a Mobile Relay (MR). This spreads out the cell coverage and increases the cell-edge throughput hence improving fairness among nodes. This article is focused on a Long Term Evolution Advanced (LTE-A) cellular network where MNs and MRs are connected through a Wireless Fidelity (WiFi) ad-hoc connection. It is proposed the use of Media Independent Handover (MIH) signaling to define an efficient dynamic routing mechanism for MR in this framework. The proposed mechanism, called MIH-Driven Relay Selection Mechanism (MIDRES), detects which is the best direct or indirect link with the BS based on information collected using MIH messages. The MNs or MRs send MIH messages when experiencing bad channel conditions, that is detected thanks to predefined thresholds. Then, the BS starts a polling process, again supported by MIH signaling, and performs optimal route selection either through the LTE-A radio interface or through a WiFi ad-hoc interface. This article examines the implementation of this mechanism and obtains the optimal thresholds that maximize operational performance. Moreover, the potential benefit of this LTE-compliant mobile relaying solution is evaluated using a calibrated simulation tool. The results show significant savings in cost of network deployment.

Dynamic Routing and Operational Controls in Workflow Management Systems

Businesses around the world are paying more attention to process management and process automation to improve organizational efficiency and effectiveness. In this paper, we describe a general framework for implementing dynamic routing and operational control mechanisms in Workflow Management Systems (WMSs). The framework consists of three techniques: workflow control tables, sequence constraints, and event-based workflow management rules. Our approach offers several unique features that are missing in commercial workflow management systems: (1) it provides more flexibility in process modeling and control; (2) it permits rework on an ad hoc basis; (3) it handles exceptions to routing and operational controls; and (4) it exploits parallelism to increase system throughput and response time. Finally, the workflow management techniques are applied to the case of consumer loan management and compared with other approaches based on static routing.