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Proceedings ArticleDOI

Processing Location Dependent Continuous Queries in Distributed Mobile Databases using Mobile Agents

07 Feb 2008-pp 119-125
TL;DR: This paper presents a system that supports distributed processing of location-dependent continuous queries on distributed mobile data in a mobile environment using mobile agents and proposes a shared incremental update mechanism, which caches the results of the previously evaluated queries and avoids redundant results thereby minimizing the data traffic in wireless environment.
Abstract: With the increase in the number of mobile users, the need for new type of services and applications is also on the rise. Particularly, a growing area of interest is to provide location dependent services to the mobile users. In this paper, we present a system that supports distributed processing of location-dependent continuous queries on distributed mobile data in a mobile environment using mobile agents. We investigate a scenario in which both the querying unit and the object being queried (target object) are capable of movement and the mobile unit is equipped with more powerful capabilities, including the storage of a small database and the capacity of data processing. Since our system deals with continuous queries, we propose a shared incremental update mechanism, which caches the results of the previously evaluated queries and avoids redundant results thereby minimizing the data traffic in wireless environment. To further reduce the data transfer we share the cached data among different queries. Our system uses mobile agents for evaluating queries, which involves data from both the server and mobile unit, and it helps in parallel processing of data and it, can efficiently track the mobile units involved in the system. The conventional query processing method like join processing of data from mobile units and server is directly applied in the mobile environment.
Citations
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Patent
03 May 2012
TL;DR: In this paper, the authors concerne des techniques for suivre de grands nombres d'objects mobiles dans un systeme de traitement d'evenements, permettant de ce fait le traitement en parallele d'une ou de plusieurs interrogations continues.
Abstract: L'invention concerne des techniques pour suivre de grands nombres d'objets mobiles dans un systeme de traitement d'evenements. Dans un ensemble de modes de realisation, un flux d'evenements d'entree peut etre recu, les evenements dans le flux d'evenements d'entree representant le deplacement d'une pluralite de geometries ou d'objets. Le flux d'evenements d'entree peut ensuite etre partage entre un certain nombre de nœuds de traitement du systeme de traitement d'evenements, permettant de ce fait le traitement en parallele d'une ou de plusieurs interrogations continues pour suivre les objets. Dans un mode de realisation particulier, le partage peut etre effectue de sorte que (1) chaque nœud de traitement soit configure pour suivre des objets dans une region spatiale predefinie, et (2) les regions spatiales pour au moins deux nœuds se superposent. Cette fenetre de superposition permet a un nœud unique de trouver, par exemple, tous les objets dans les limites d'une distance particuliere d'un objet cible, meme si l'objet cible se deplace de la region de ce nœud vers la region de superposition d'un autre nœud.

1 citations

Journal Article
TL;DR: A new approach for processing location-dependent queries is introduced that deals with scenarios where users issuing queries as well as objects involved in such queries can change their location, and provides a completely decentralised solution that optimises wireless communication costs by using mobile agents.
Abstract: Nowadays the number of mobile device users is continuously increasing. However the available data services for those users are rare and usually provide an inefficient performance. More particularly, a growing interest is arising around location-based services but the processing of location-dependent queries is still a subject of research in the new mobile computing environment. Special difficulties arise when considering the need of keeping the answer to these queries up-to-date, due to the mobility of involved objects. In this paper we introduce a new approach for processing location-dependent queries that presents the following features: 1) it deals with scenarios where users issuing queries as well as objects involved in such queries can change their location, 2) it deals with continuous queries and so answers are updated with a certain frequency, 3) it provides a completely decentralised solution and 4) it optimises wireless communication costs by using mobile agents. We focus on the way in which data presented to the user must be refreshed in order to show an up-to-date answer but optimising communications effort.
References
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Journal ArticleDOI
TL;DR: This paper is an effort to survey these techniques and to classify this research in a few broad areas in the area of data management in mobile computing.
Abstract: The emergence of powerful portable computers, along with advances in wireless communication technologies, has made mobile computing a reality. Among the applications that are finding their way to the market of mobile computing-those that involve data management-hold a prominent position. In the past few years, there has been a tremendous surge of research in the area of data management in mobile computing. This research has produced interesting results in areas such as data dissemination over limited bandwidth channels, location-dependent querying of data, and advanced interfaces for mobile computers. This paper is an effort to survey these techniques and to classify this research in a few broad areas.

416 citations

Proceedings ArticleDOI
20 May 2001
TL;DR: This paper gives a formalization of location relatedness in queries and distinguishes location dependence and location awareness and provides thorough examples to support the approach.
Abstract: The advances in wireless and mobile computing allow a mobile user to perform a wide range of aplications once limited to non-mobile hard wired computing environments As the geographical position of a mobile user is becoming more trackable, users need to pull data which are related to their location, perhaps seeking information about unfamiliar places or local lifestyle data In these requests, a location attribute has to be identified in order to provide more efficient access to location dependent data, whose value is determined by the location to which it is related Local yellow pages, local events, and weather information are some of the examples of these dataIn this paper, we give a formalization of location relatedness in queries We differentiate location dependence and location awareness and provide thorough examples to support our approach

129 citations

Journal ArticleDOI
TL;DR: A system that supports distributed processing of continuous location-dependent queries in mobile environments and uses mobile agents to carry the processing tasks wherever they are needed.
Abstract: With the current advances of mobile computing technology, we are witnessing an explosion in the development of applications that provide mobile users with a wide range of services. In this paper, we present a system that supports distributed processing of continuous location-dependent queries in mobile environments. The system that we propose presents the following main advantages: 1) it is a general solution for the processing of location-dependent queries in scenarios where not only the users issuing queries, but also other interesting objects can move; 2) it performs an efficient processing of these queries in a continuous way; 3) it is especially well adapted to environments where location data are distributed in a network and processing tasks can be performed in parallel, allowing a high scalability; and 4) it optimizes wireless communications. We use mobile agents to carry the processing tasks wherever they are needed. Thus, agents are in charge of tracking the location of interesting moving objects and refreshing the answer to a query efficiently. We evaluate the usefulness of the presented proposal showing that the system achieves a good precision and scales up well

85 citations


"Processing Location Dependent Conti..." refers background or methods in this paper

  • ...This network of agents helps in processing the query and getting the reply back to the query issuer [ 11 ] [12]....

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  • ...The architecture presented in [ 11 ] and [12] presents a hierarchical network of agents from the query issuer to the target proxy....

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  • ...An architecture based on mobile agents [ 11 ] for evaluating LDCQ was described by the authors Sergio Ilarri et.al....

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  • ...Location dependent continuous queries in a wireless environment can be processed with the help of agents [10] [7] [ 11 ][12]....

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  • ...Apart from their previous works they have also described a system in paper [ 11 ] that supports distributed processing of continuous locationdependent queries in mobile environment....

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Proceedings ArticleDOI
16 Jul 2003
TL;DR: A set of dynamic data management strategies that employs judicious caching, proactive server pushing and neighborhood replication to reduce service cost and improve response time under changing user mobility and access patterns are proposed.
Abstract: We characterize the dynamic data management problem for location based services (LBS) in mobile environments and devise a cost model for servicing both location independent and location dependent data. The cost analysis leads to a set of dynamic data management strategies that employs judicious caching, proactive server pushing and neighborhood replication to reduce service cost and improve response time under changing user mobility and access patterns. Simulation results suggest that different strategies are effective for different types of data in response to different patterns of movement and information access.

68 citations


"Processing Location Dependent Conti..." refers background in this paper

  • ...The issues related to dynamic data management and strategies such as judicious caching, proactive server pushing and neighborhood replication for LBS and the use of mobile agents have been studied in [ 13 ]....

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Journal ArticleDOI
TL;DR: Three tuple transmission approaches that can be used to determine the transmission time of tuples in the answer set of a location-dependent CQ are proposed and the relative performance of the proposed approaches under different settings of environmental parameters is evaluated.

53 citations


"Processing Location Dependent Conti..." refers methods in this paper

  • ...Since continuous queries involve the transmission of result for every update we can optimize the data transfer by using incremental updates [ 6 ] [8]....

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  • ...The incremental update scheme proposed by papers [ 6 ] and [8] did not deal about sharing incremental updates between different types of queries....

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