Acquisitional Query Processing In Sensor Networks • 125 Section 6 discusses our adaptive, power-sensitive model for query execution and result collection. 2. SENSOR NETWORK OVERVIEW We begin with an overview of some recent sensor network deployments, and then discuss properties of sensor nodes and sensor networks in general, provid-

بیشتر

The TinyDB [8,9] and Cougar [14,15] projects investigate tree-based routing and scheduling techniques for processing aggregate queries like avg, count, sum, min and max in sensor networks. The concept of semantic routing trees (SRTs) [9] is used to forward queries only to children that satisfy the query …

بیشتر

Wireless sensor networks (WSNs) have received increasing attention in the past decade. In existing studies for query processing of WSNs, each sensor node measures environmental parameters such as ...

بیشتر

we introduce our model of a sensor network, sensor data, and the class of queries that we consider in this paper. We then demonstrate our algorithms to process simple aggregate queries with in-network aggregation (Section 3), and investigate the interaction between the routing layer and the query …

بیشتر

in-network processing in sensor networks. The filter framework [7] in Directed Diffusion allows custom code to run on the sensor nodes. Thus, filters can be used to process the information (aggregation) in the network before data reaches the querying node. TinyDBD is an attempt to use this architecture to implement an SQL-like query ...

بیشتر

New Applications: network monitoring, sensor networks, telecom call records • Data arrives in the form of continuous stream – Order and rate or arrival not under the control of the system • Queries are long running • Most assumptions in relational database systems break Computation over Data Streams

بیشتر

In addition, when the sensing areas of sensor nodes are disjoint, the coordinator of each sensor becomes itself and we perform traditional aggregate query processing. Thus, the problem we are considering is a generalization of the traditional in-network aggregation problem.

بیشتر

network aggregation and distributed query processing. Yao and Gehrke in [14] extend the previous guidelines focusing the query processing issue and propose the definition of a query layer that improves the capabilities of a generic sensor network, and define a de-clarative language for efficiently in-network query processing.

بیشتر

This study proposes a method of in-network aggregate query processing to reduce the number of messages incurred in a wireless sensor network. When aggregate queries are …

بیشتر

Aggregate queries. Approximation. 1. Introduction. Densely distributed sensor networks are used in a variety of monitoring applications ranging from measurements of meteorological data (like temperature, pressure, humidity), noise levels, chemicals etc., to complex military vehicle surveillance and tracking applications.

بیشتر

on sensor networks has been advocated [24, 29], with particular attention paid to efficient query processing for aggregation queries [24, 29, 31]. In the TAG system [24], users connect to the sensor network using a workstation or base station directly connected to a sensor designated as the sink. Aggregate queries over the sensor data are ...

بیشتر

aggregate query processing definition - aggregate query processing definition, optimizing aggregate queries in cache. request: regionbased query processing in sensor networks. the processing of grouped aggregate queries. however, since a region in our approach is defined as a .. inside a circle having a diameter d by definition 1.

بیشتر

aggregate queriesover sensor networksin anenergy{e cient manner. 1.1 Query Processing in Sensor Networks From the database perspective, in{network aggregation is a mode for evaluating aggregate queries over the sensor net-work. The common approach to (aggregate) query process-ing in sensor networks has two phases: the dissemination phase and ...

بیشتر

TinyDB: In-Network Query Processing in TinyOS. Version 0.4, September 2003. 9. Madden, Robert Szewczyk, Michael J. Franklin, and David Culler. Supporting Aggregate Queries Over Ad-Hoc Wireless Sensor Networks.

بیشتر

Assembling Regions for Efficacious Aggregate Query Processing in Wireless Sensor Networks by Apostolos Fertis Diploma, Electrical and Computer Engineering (2003) National Technical University of Athens Submitted to the Department of Electrical Engineering and Computer Science in partial fulfillment of the requirements of

بیشتر

sensor networks. Users acquire interesting data by issuing SQL-like queries while the underlying data retrieval and col-lection processes are transparent to them. Many of the early works on query processing in sensor networks have focused on aggregate queries such as COUNT, SUM and MAX, and have developed in-network aggregation techniques that sig-

بیشتر

running queries on the sensor readings, and periodically receives data from the network (typically via a single node, called the sink). Aggregate queries (e.g., SUM, MAX, etc.) constitute a wide and important query class in sensor networks. In the naive case, the querier collects all the raw data from the sensors and performs the aggregation ...

بیشتر

region specified in the query is changed. Our query processing scheme is also related to aggregate queries in sensor networks. Even if many works have been proposed to process aggregate queries, only a few works deal with grouped aggregate queries. TAG [10] propose a grouped in-network aggregation method. In this method,

بیشتر

Abstract: An important class of queries over sensor networks are network-wide aggregation queries. In this work we study a class of aggregation queries which we refer to as aggregate threshold queries. The goal of an aggregate threshold query is to continuously monitor the network and give a notification every time an aggregated value crosses a predetermined threshold …

بیشتر

sensor network, we focus on the processing of spatial aggregation queries. 2.2 Spatial Aggregation Queries Without loss of generality, we assume that each sensor maintains data in the following form: readings,loc. Based on the grid structured sensor network, our spatial aggregation query is expressed in an SQL-like syntax as exemplified in the ...

بیشتر

1.1 Query Processing in Sensor Networks From databases perspective, in–network aggregation is a mode for evaluating aggregate queries over the sensor network. Sensor network applications rely heavily on aggregate queries. Queries are also considered a natural way for users to interact with the sensor network [23]. Therefore, several studies ...

بیشتر

niques designed for wireless sensor networks. On the other side, the aggregate query processing module is embedded in-side the server to support aggregate query processing over anonymized locations. TinyCasper system administrators can change the privacy requirement, i.e., k-anonymity re-quirement, at anytime. Finally, system users can issue snap-

بیشتر

nell University [24] (Cougar) have developed energy efficient query processing architectures over sensor networks. Their approach is based on a couple of observations : first, for a user, the individual sensor values do not hold much value. For example, in a sensor network spanning thousands of nodes, the user would like to know

بیشتر

Sensor nodes are generally highly constrained, in particular regarding their energy and memory resources. While simple queries such as SELECT and AGGREGATE queries in wireless sensor networks have been addressed in the literature, the processing of join queries in sensor networks remain to be investigated.

بیشتر

Interplay of processing and routing in aggregate query optimization for sensor networks Niki Trigoni Alexandre Guitton Antonios Skordylis Computing Laboratory, University of Oxford, Oxford OX1 3QD, UK Abstract. This paper presents a novel approach to processing continuous aggre-gate queries in sensor networks, which lifts the assumption of tree ...

بیشتر

Recent sensor networks research has produced a class of data stor-age and query processing techniques called Data-Centric Storage that leverages locality-preserving distributedindexes like DIM,DIFS, and GHT to efciently answer multi-dimensional range and range-aggregate queries. These distributed indexes offer a rich design

بیشتر

1 INTRODUCTION. Wireless sensor networks (WSNs), constituted of a large number of resource-limited sensor nodes, complete monitoring and investigation through data aggregation and query, creating a wide range of application scenes [1, 2].WSNs are applied to all aspects of life, such as national defence, military, aerospace, traffic management, environmental monitoring and so on [3, 4].

بیشتر

This paper presents a query-driven approach to routing and processing continuous aggregate queries in sensor networks. Given a query workload and a special-purpose gateway node where results are expected, the query optimizer exploits query correlations in order to generate an energyefficient distributed evaluation plan.

بیشتر

12%Query processing on continuous aggregates. In this work, we assume sensor nodes have been organized into a spanning tree and each sensor will generate a sensing value in each round (a short time period). After the creation of a network topology, users can pose a continuous aggregate query, such as AVG, to the network.

بیشتر

Supporting Aggregate Queries Over Ad-Hoc Wireless Sensor Networks Madden UC Berkeley With Robert Szewczyk, Michael Franklin, and David Culler WMCSA June 21, 2002 Motivation: Sensor Nets and In-Network Query Processing Many Sensor Network Applications are Data Oriented Queries Natural and Efficient Data Processing Mechanism Easy (unlike ...

بیشتر