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ABSTRACT: Various data dissemination methods have been proposed over the years to reduce energy consumption in wireless sensor networks. One thing common and pivotal to every dissemination approach's performance is the network topology used underneath. Moving sink and moving event pose major challenge while developing data dissemination schemes for wireless sensor networks. In this paper, we propose a dual radio based grid construction scheme which exploits dual radio mode of a sensor node to form a grid across sensor field. Grid construction is initiated by the sink appearing in the sensor field when no valid grid is present. Any sink appearing during valid grid period shares existing grid and thus obviate the need to construct new grid. Both short and long radio transmission ranges of a dual radio decides the cell size and all nodes with in a cell form a cluster with one of nodes at corners of the cell acting as cluster head. Based upon this grid, we develop novel methods for handling multiplicity and movements of sinks and events in sensor field so as to ensure continuous data delivery from source nodes to sink or sinks. We conducted simulation experiments to evaluate GBDD in different scenarios and compared it with Two-Tier Data Dissemination (TTDD) approach. Results clearly show significant improvements in performance in most of scenarios as compared to TTDD.
Advanced Computing and Communications, 2008. ADCOM 2008. 16th International Conference on; 01/2009
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ABSTRACT: A wireless sensor network has potential to monitor stimulus around it. Sensor networks have severe energy constraints, low data rate with high redundancy, and many-to-one flows. Thus, data centric mechanisms that perform in-network aggregation of data are needed. Clustering is one of the data centric mechanisms in which various cluster heads perform in-network aggregation of data. Thus, there is more load on cluster heads than regular nodes. Therefore, for load balancing the role of cluster head should be rotated among other regular nodes. Moreover, cluster heads may fail and disrupt communication. Handling such faulty cluster heads is vital to correct and efficient working of these networks. In this paper, we propose a dynamic and distributed new cluster head election algorithm with fault tolerance capabilities based upon two-level clustering scheme. If energy level of current cluster head falls below a certain limit or any cluster head fails to communicate then election process is started. Based on energy levels, election process appoints a cluster head and a back-up node to handle cluster head failure. Back-up node automatically takes over the role of cluster head once it detects failure of current cluster head. All sensors are homogeneous in nature and working in dual mode. Simulation results show significant energy savings when compared with other clustering scheme like energy efficient multi-level clustering (EEMC).
Networks, 2008. ICON 2008. 16th IEEE International Conference on; 01/2009
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ABSTRACT: In this paper, we propose a caching scheme for wireless sensor networks which exploits cooperation among various sensor nodes in a zone formed around few sensor nodes. Zones are created by using dual radio mode of sensor nodes i.e. high and low power transmission ranges define zone size. In order to realize much larger cumulative cache, a node along with its own storage utilizes storage of sensor nodes in zone formed around it. Zone size is taken such that all nodes in a zone communicate with each other in single-hop using low power radio and hence conserves energy in cumulative cache management. Considering multiple and mobile sinks in sensor field, we develop unique token based cache admission control, cache discovery and least importance based item replacement policy. Proposed caching scheme is applied to two-tier data dissemination (TTDD) approach and newly proposed dual radio based data dissemination (DRDD) approach. Simulation results show significant gains in energy efficiency when cooperative caching is used in both approaches as compared to scenarios when these dissemination schemes do not employ caching.
Networks, 2008. ICON 2008. 16th IEEE International Conference on; 01/2009
