Current Issue : October - December Volume : 2014 Issue Number : 4 Articles : 5 Articles
Wireless sensor networks (WSNs) have been broadly studied with advances in ubiquitous computing environment. Because the\nresource of a sensor node is limited, it is important to use energy-efficient routing protocol inWSNs.The cluster-based routing is\nan efficient way to reduce energy consumption by decreasing the number of transmitted messages to the sink node. LEACH is the\nmost popular cluster-based routing protocol, which provides an adaptive cluster generation and cluster header rotation. However,\nits communication range is limited since it assumes a direct communication between sensor nodes and a sink node. To resolve\nthis problem, we propose a new energy-efficient cluster-based routing protocol, which adopts a centralized clustering approach to\nselect cluster headers by generating a representative path. To support reliable data communication, we propose a multihop routing\nprotocol that allows both intra- and intercluster communications. Based on a message success rate and a representative path, the\nsensor nodes are uniformly distributed in clusters so that the lifetime of network can be prolonged. Through performance analysis,\nwe show that our energy-efficient routing protocol outperforms the existing protocols up to 2 times, in terms of the distribution of\ncluster members, the energy consumption, and the reliability of a sensor network....
Nonuniform node deployment makes the cluster-based routing protocol less efficient in wireless sensor networks (WSNs). Energy\naware distributed clustering (EADC) is one of the cluster-based routing protocols proposed for networks with nonuniform node\ndistribution, which can effectively balance the energy consumption among the nodes. However, due to the nonuniform node\ndistribution, there is a redundancy in sensed and transmitted data in dense area. This unnecessary energy consumption is not\nconsidered in EADC. Therefore, in this paper, a new algorithm called scheduled activity EADC (SA-EADC) is proposed. SAEADC\nexploits the redundant nodes and turns them off for the current round. The redundant nodes are scheduled based on their\nresidual energy to work alternatively.The results show that SA-EADC significantly decreases the energy consumption and extends\nthe network lifetime without degradation in coverage and sensing reliability of the network....
Data aggregation is a useful technology that can decrease the communication bandwidth cost in the process of data gathering in\nVANETs. However, data aggregation may lose some data accuracy. Current data aggregation schemes in VANETs only consider\nsaving bandwidth cost while ignoring the application requirement, which may result in the inaccuracy of aggregated data for\ndynamic routing application.Therefore, we propose a framework in which application demands are considered in the process of\ndata aggregation to ensure the accuracy of aggregated data for dynamic routing application.The framework consists of three parts:\nextracting QoI constraints of aggregated data, distributing the QoI-based data gathering queries, routing and aggregating data with\nQoI constraints. First, we propose average allocation method to handle the demand of single user and utilize convex optimization\nto handlemultiuser demands. Then, we distribute theQUERY message withQoI constraints in the interested area. Last, we propose\nQoI-DG protocol to do two kinds of data aggregation operation, namely, AVERAGE aggregation and HISTOGRAM aggregation.\nSimulation experiments show that our proposed method can increase about 20 percent in the collected data rate and save 15 percent\ncommunication bandwidth cost in the process of data gathering in VANETs....
Routingmetric helps select optimal path fromsource node to destination node. It is the key for the whole network performance and\nneeds to be designed carefully. Existing routing metrics have at least one of the limitations listed below. (1) Internet-oriented traffic\nis considered only, and client-oriented traffic is omitted, or vice versa. (2) Route selection is done in mesh network with a single\ngateway, so route selection is only related to selecting a route path without selecting gateway node. (3) The isotonic requirement\ncannot be satisfied. In order to conquer the limitations aforementioned and guide route selection, an isotonic differentiated service\nbased interference-aware routing metric is proposed for mesh networks withmultiple gateways. Traffic pattern, node load, gateway\nload, and intraflow and interflow interference are all taken into consideration to guide the selection of best path and best gateway.\nSimulations reveal that the proposed metric outperforms state-of-art metrics in terms of the average network throughput and\naverage end-to-end delay....
A wireless sensor network (WSN) is a collection of sensor nodes that dynamically self-organize themselves into a wireless network\nwithout the utilization of any preexisting infrastructure. One of the major problems inWSNs is the energy consumption, whereby\nthe network lifetime is dependent on this factor. In this paper, we propose an optimal routing protocol for WSN inspired by the\nforaging behavior of ants. The ants try to find existing paths between the source and base station. Furthermore, we have combined\nthis behavior of ants with fuzzy logic in order for the ants to make the best decision. In other words, the fuzzy logic is applied to\nmake the use of these paths optimal. Our algorithm uses the principles of the fuzzy ant colony optimization routing (FACOR) to\ndevelop a suitable problem solution. The performance of our routing algorithm is evaluated by Network Simulator 2 (NS2). The\nsimulation results show that our algorithm optimizes the energy consumption amount, decreases the number of routing request\npackets, and increases the network lifetime in comparison with the original AODV....
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