Histogram and median queries in wireless sensor networks

  • Author / Creator
    Ammar, Khaled A.
  • Recently, Wireless Sensor Networks (WSNs) have been used in many monitoring applications, e.g., environment monitoring. A WSN consists of a set of nodes, each having one or more sensors to measure a phenomena. Nodes are connected to each other using wireless radio communications. Typically, there is at least one base station that functions as an interface between the monitored area and the end user.

    In many applications, users are interested in statistical summaries of the observed data, e.g., histograms reflecting the distribution of the collected values. In this thesis we propose two main contributions: (1) an efficient algorithm for answering Histogram queries in a WSN, and (2) efficient algorithms for answering snapshot and continuous Median queries in a WSN.

    While designing applications for the WSN, the main challenge is the battery life time. For WSN nodes, sending a message consumes a significantly higher amount of energy than processing information inside the node. Therefore, we design our proposed algorithms in order to minimize the energy consumption and/or transmission cost, i.e. number of sent bytes, and consequently extend its lifespan. Our experimental results, using synthetic and real datasets, show that our proposed solutions are indeed able to substantially extend the lifespan of the WSN when compared to previously proposed solutions.

  • Subjects / Keywords
  • Graduation date
    Fall 2011
  • Type of Item
  • Degree
    Master of Science
  • DOI
  • License
    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.