The document discusses performance evaluation of transaction processing in mobile database systems. It analyzes three execution strategies - mobile host strategy (MHS), fixed host strategy (FHS), and combined host strategy (CHS) - and finds that CHS performs best. Under CHS, some transaction operations execute on the mobile host and some on the fixed host, utilizing benefits of both MHS and FHS while minimizing their individual performance penalties. The integrated approach of CHS is shown to match or improve upon the performance of MHS and FHS for various workload mixtures.
The advancement in mobile technology and wireless network increase the using of mobile device in database
driven application, these application require high reliability and availability due to nature inheritance of
mobile environment, transaction is the center component in database systems, In this paper we present
useful work done in mobile transaction, we show the mobile database environment and overview a lot of
proposed model of mobile transaction and show many techniques used to enhance transaction execution.
Grid fabrication of traffic maintenance system clustering at road junctionseSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
A NEW APPROACH TO STOCHASTIC SCHEDULING IN DATA CENTER NETWORKSIJCNCJournal
The Quality of Service (QoS) of scheduling between latency-sensitive small data flows (a.k.a. mice) and throughput-oriented large ones (a.k.a. elephants) has become ever challenging with the proliferation of cloud-based applications. In light of this mounting problem, this work proposes a novel flow control scheme, HOLMES (HOListic Mice-Elephants Stochastic), which offers a holistic view of global congestion awareness as well as a stochastic scheduler of mixed mice-elephants data flows in Data Center Networks (DCNs). Firstly, we theoretically prove the necessity for partitioning DCN paths into sub-networks using a stochastic model. Secondly, the HOLMES architecture is proposed, which adaptively partitions the available DCN paths into low-latency and high-throughput sub-networks via a global congestion-aware scheduling mechanism. Based on the stochastic power-of-two-choices policy, the HOLMES scheduling mechanism acquires only a subset of the global congestion information, while achieves close to optimal load balance on each end-to-end DCN path. We also formally prove the stability of HOLMES flow scheduling algorithm. Thirdly, extensive simulation validates the effectiveness and dependability of HOLMES with select DCN topologies. The proposal has been in test in an industrial production environment. An extensive survey of related work is also presented.
International Journal of Computational Engineering Research(IJCER) ijceronline
nternational Journal of Computational Engineering Research (IJCER) is dedicated to protecting personal information and will make every reasonable effort to handle collected information appropriately. All information collected, as well as related requests, will be handled as carefully and efficiently as possible in accordance with IJCER standards for integrity and objectivity.
Transaction management techniques and practices in current cloud computing en...ijdms
Distributed database management systems (DDBMs) have limited capacity to manage overhead of distributed transactions due to certain failures. These types of failures don’t guarantee the enforcement of transactional properties and which reduces the scalability and availability of these systems. Research in this area proved that scaling out while providing consistency of transactions and guaranteeing availability in the presence of different failures in distributed computing environment is not feasible. As a result, the database community have used vertical scaling rather than horizontal scaling. Moreover changes in data access patterns resulting from a new generation of web applications with high scalability and availability guarantees weaker consistency. In this paper we have analyse that how different systems such as ElasTraS, Mstore, Sinfonia, ecStore and Gstore provide scalable transactional data access in cloud computing
environment. We have also discussed transaction management (TM) in Gstore in detail and compared with
other techniques and protocols used in current cloud based systems.
CONGESTION CONTROL USING FUZZY BASED LSPS IN MULTIPROTOCOL LABEL SWITCHING NE...ijfcstjournal
In this paper, we have proposed a fuzzy based decision making component for high volume traffic MPLS
networks, by implementing Traffic Engineering, Quality of Service and Multipath routing. The approach
explicitly proves to be successful in solving the issues and challenges pertaining to stability, scalability in
high volume and dynamic traffic. Furthermore, it will work to handle congestion by higher link utilization
and provides efficient rerouting of traffic along with fault tolerance in the network. In this research work,
fuzzy calculations are done for fixing the attributes of the MPLS label(s), which is put on particular packet
representing the Forwarding Equivalence Class. Fuzzy controller consists of two sub fuzzy systems- Label
Switched Path setup System (LsS) and Traffic Splitting System (TSS). The computation of dynamic status of
Load and Delay is utilized by LsS to arrange the paths in preference order. The attained Link Capacity and
Utilization Rate are employing by TSS for maintaining congestion free path. The impact of this is to
facilitate, we have better decision making for splitting the traffic for different promising paths. This was
apparent from the series of traffic scenarios. Observations are obtained using this realization.
Irrational node detection in multihop cellular networks using accounting centereSAT Journals
Abstract In multihop cellular networks mobile nodes typically transmit packets during intermediate mobile nodes for enhancing recital. Stingy nodes typically don't collaborate that incorporates a negative result on the network fairness and recital. A fair, inexpensive and best incentive mechanism by Selfish Node Detection (FESCIMbySND) has been projected to stimulate the mobile node’s cooperation. Hashing operations area unit employed in order to extend the safety. Trivial Hash perform has been wont to improve end-to-end delay and outturn. Additionally Cyclic Redundancy Check Mechanism has been used to spot the ridiculous nodes that involve themselves in sessions with the intention of dropping the in sequence packets. Moreover, to cut back the impact at the Accounting Center a Border node has been commend the task of propose the checks employing a digital signature. Keywords: Border Node Mechanism, Cyclic Redundancy Check, Selfish nodes, Trivial Hash Function
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
The advancement in mobile technology and wireless network increase the using of mobile device in database
driven application, these application require high reliability and availability due to nature inheritance of
mobile environment, transaction is the center component in database systems, In this paper we present
useful work done in mobile transaction, we show the mobile database environment and overview a lot of
proposed model of mobile transaction and show many techniques used to enhance transaction execution.
Grid fabrication of traffic maintenance system clustering at road junctionseSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
A NEW APPROACH TO STOCHASTIC SCHEDULING IN DATA CENTER NETWORKSIJCNCJournal
The Quality of Service (QoS) of scheduling between latency-sensitive small data flows (a.k.a. mice) and throughput-oriented large ones (a.k.a. elephants) has become ever challenging with the proliferation of cloud-based applications. In light of this mounting problem, this work proposes a novel flow control scheme, HOLMES (HOListic Mice-Elephants Stochastic), which offers a holistic view of global congestion awareness as well as a stochastic scheduler of mixed mice-elephants data flows in Data Center Networks (DCNs). Firstly, we theoretically prove the necessity for partitioning DCN paths into sub-networks using a stochastic model. Secondly, the HOLMES architecture is proposed, which adaptively partitions the available DCN paths into low-latency and high-throughput sub-networks via a global congestion-aware scheduling mechanism. Based on the stochastic power-of-two-choices policy, the HOLMES scheduling mechanism acquires only a subset of the global congestion information, while achieves close to optimal load balance on each end-to-end DCN path. We also formally prove the stability of HOLMES flow scheduling algorithm. Thirdly, extensive simulation validates the effectiveness and dependability of HOLMES with select DCN topologies. The proposal has been in test in an industrial production environment. An extensive survey of related work is also presented.
International Journal of Computational Engineering Research(IJCER) ijceronline
nternational Journal of Computational Engineering Research (IJCER) is dedicated to protecting personal information and will make every reasonable effort to handle collected information appropriately. All information collected, as well as related requests, will be handled as carefully and efficiently as possible in accordance with IJCER standards for integrity and objectivity.
Transaction management techniques and practices in current cloud computing en...ijdms
Distributed database management systems (DDBMs) have limited capacity to manage overhead of distributed transactions due to certain failures. These types of failures don’t guarantee the enforcement of transactional properties and which reduces the scalability and availability of these systems. Research in this area proved that scaling out while providing consistency of transactions and guaranteeing availability in the presence of different failures in distributed computing environment is not feasible. As a result, the database community have used vertical scaling rather than horizontal scaling. Moreover changes in data access patterns resulting from a new generation of web applications with high scalability and availability guarantees weaker consistency. In this paper we have analyse that how different systems such as ElasTraS, Mstore, Sinfonia, ecStore and Gstore provide scalable transactional data access in cloud computing
environment. We have also discussed transaction management (TM) in Gstore in detail and compared with
other techniques and protocols used in current cloud based systems.
CONGESTION CONTROL USING FUZZY BASED LSPS IN MULTIPROTOCOL LABEL SWITCHING NE...ijfcstjournal
In this paper, we have proposed a fuzzy based decision making component for high volume traffic MPLS
networks, by implementing Traffic Engineering, Quality of Service and Multipath routing. The approach
explicitly proves to be successful in solving the issues and challenges pertaining to stability, scalability in
high volume and dynamic traffic. Furthermore, it will work to handle congestion by higher link utilization
and provides efficient rerouting of traffic along with fault tolerance in the network. In this research work,
fuzzy calculations are done for fixing the attributes of the MPLS label(s), which is put on particular packet
representing the Forwarding Equivalence Class. Fuzzy controller consists of two sub fuzzy systems- Label
Switched Path setup System (LsS) and Traffic Splitting System (TSS). The computation of dynamic status of
Load and Delay is utilized by LsS to arrange the paths in preference order. The attained Link Capacity and
Utilization Rate are employing by TSS for maintaining congestion free path. The impact of this is to
facilitate, we have better decision making for splitting the traffic for different promising paths. This was
apparent from the series of traffic scenarios. Observations are obtained using this realization.
Irrational node detection in multihop cellular networks using accounting centereSAT Journals
Abstract In multihop cellular networks mobile nodes typically transmit packets during intermediate mobile nodes for enhancing recital. Stingy nodes typically don't collaborate that incorporates a negative result on the network fairness and recital. A fair, inexpensive and best incentive mechanism by Selfish Node Detection (FESCIMbySND) has been projected to stimulate the mobile node’s cooperation. Hashing operations area unit employed in order to extend the safety. Trivial Hash perform has been wont to improve end-to-end delay and outturn. Additionally Cyclic Redundancy Check Mechanism has been used to spot the ridiculous nodes that involve themselves in sessions with the intention of dropping the in sequence packets. Moreover, to cut back the impact at the Accounting Center a Border node has been commend the task of propose the checks employing a digital signature. Keywords: Border Node Mechanism, Cyclic Redundancy Check, Selfish nodes, Trivial Hash Function
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
International Journal of Engineering Research and Development (IJERD)IJERD Editor
journal publishing, how to publish research paper, Call For research paper, international journal, publishing a paper, IJERD, journal of science and technology, how to get a research paper published, publishing a paper, publishing of journal, publishing of research paper, reserach and review articles, IJERD Journal, How to publish your research paper, publish research paper, open access engineering journal, Engineering journal, Mathemetics journal, Physics journal, Chemistry journal, Computer Engineering, Computer Science journal, how to submit your paper, peer reviw journal, indexed journal, reserach and review articles, engineering journal, www.ijerd.com, research journals,
yahoo journals, bing journals, International Journal of Engineering Research and Development, google journals, hard copy of journal
Research Inventy : International Journal of Engineering and Scienceinventy
Research Inventy : International Journal of Engineering and Science
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed
New Proposedclassic Cluster Layer Architecture for Mobile Adhoc Network (cclam)CSCJournals
Organization, scalability and routing have been identified as key problems hindering viability and commercial success of mobile ad hoc networks. Clustering of mobile nodes among separate domains has been proposed as an efficient approach to address those issues. In this work, we introduce an efficient distributed clustering layers algorithm that uses location metrics for cluster formation. Our proposed solution mainly addresses cluster stability, manageability issues. Also, unlike existing active clustering methods, our algorithm relieves the network from the unnecessary burden of control messages broadcasting, especially for relatively static network topologies. This is achieved through adapting broadcast period according to mobile nodes mobility pattern. The efficiency, scalability and competence of our algorithm against alternative approaches have been shows in algorithm
Peer to peer cache resolution mechanism for mobile ad hoc networksijwmn
In this paper we investigate the problem of cache resolution in a mobile peer to peer ad hoc network. In our
vision cache resolution should satisfy the following requirements: (i) it should result in low message
overhead and (ii) the information should be retrieved with minimum delay. In this paper, we show that
these goals can be achieved by splitting the one hop neighbours in to two sets based on the transmission
range. The proposed approach reduces the number of messages flooded in to the network to find the
requested data. This scheme is fully distributed and comes at very low cost in terms of cache overhead. The
experimental results gives a promising result based on the metrics of studies
In this paper we explore the issue of store determination in a portable shared specially appointed system. In our vision reserve determination ought to fulfill the accompanying prerequisites: (i) it ought to bring about low message overhead and (ii) the data ought to be recovered with least postponement. In this paper, we demonstrate that these objectives can be accomplished by part the one bounce neighbors into two sets in view of the transmission run. The proposed approach lessens the quantity of messages overflowed into the system to discover the asked for information. This plan is completely circulated and comes requiring little to no effort as far as store overhead. The test comes about gives a promising outcome in view of the measurements of studies.
Synthesis of Non-Replicated Dynamic Fragment Allocation Algorithm in Distribu...IDES Editor
Distributed databases have become the most
essential technology for recent business organizations. In most
of the cases Distributed Databases are developed in a Bottom-
Up approach, fragmentation exists beforehand. The optimum
allocation of those fragments is the only way, which can be
exploited by the designers to increase the performance,
efficiency, reliability and availability of the Distributed
Database in the realistic dynamic environment, where the access
probabilities of nodes to fragments change over time. In this
paper, a new dynamic fragment allocation algorithm is
proposed in Non-Replicated allocation scenario, which
incorporates the time constraints of database accesses, volume
threshold and the volume of data transmitted in successive time
intervals to dynamically reallocate fragments to sites at runtime
in accordance with the changing access patterns. It will migrate
a fragment to a particular site only when that site has made
data transfer higher than all other sites and greater than the
threshold value from or to that fragment consistently in some
recent time intervals. The choice of the volume threshold, the
number of time intervals and the duration of each time interval
are the most important factors which regulate the frequency
of fragment reallocations. The proposed algorithm will decrease
the movement of fragments over the network and data transfer
cost and will also improve the overall performance of the system
by dynamically allocating fragments in a most optimum and
intuitive manner.
A MARKOVIAN MODEL FOR INTERNET OF THINGS APPLICATIONIJCNCJournal
Internet of Things (IoT) allows communication among human-to-things, things-to-human, and things-tothings that are incorporated into an information networks allowing automatic information interchange and
the processing of data at real time. In this paper, we conduct a performance analysis of a real application
defined through four traffic classes with the priorities present in smart cities using Continuous Time
Markov Chains(CTMC). Based on a finite capacity queuing system, we propose a new cost-effective
analytical model with a push-out management scheme in favor of the highest priority (emergency) traffic.
Based on the analytical model, several performance measures for different traffic classes have been
studiedextensively including blocking probability; push out probability, delay, channel utilization as well as
overall system performance.
Adaptive Offloading in Mobile Cloud Computing by automatic partitioning approach of tasks is the idea to augment execution through migrating heavy computation from mobile devices to resourceful cloud servers and then receive the results from them via wireless networks. Offloading is an effective way to
overcome the resources and functionalities constraints
of the mobile devices since it can release them from
intensive processing and increase performance of the
mobile applications, in terms of response time.
Offloading brings many potential benefits, such as
energy saving, performance improvement, reliability
improvement, ease for the software developers and
better exploitation of contextual information.
Parameters about method transitions, response times,
cost and energy consumptions are dynamically reestimated
at runtime during application executions.
A Survey on the Common Network Traffic Sources ModelsCSCJournals
Selecting the appropriate traffic model can lead to the successful design of networks. The more accurate is the traffic model the better is the system quantified in terms of its performance Successful design lead to enhancement the overall performance of the whole of network .in literature there is innumerous traffic models proposed for understanding and analyzing the traffic characteristics of networks. Consequently, the study of traffic models to understand the features of the models and identify eventually the best traffic model, for a concerned environment has become a crucial and lucrative task. Good traffic modeling is also a basic requirement for accurate capacity planning. This paper provides an overview of some of the widely used network traffic models, highlighting the core features of the model and traffic characteristics they capture best. Finally we found that the N_BURST traffic model can capture the traffic characteristics of most types of networks, under every possible circumstance rather than any type of traffic model.
LIGHTWEIGHT MOBILE WEB SERVICE PROVISIONING FOR THE INTERNET OF THINGS MEDIATIONijujournal
Emerging sensor-embedded smartphones motivated the mobile Internet of Things research. With the integrated embedded hardware and software sensor components, and mobile network technologies, smartphones are capable of providing various environmental context information via embedded mobile device-hosted Web services (MWS). MWS enhances the capability of various mobile sensing applications such as mobile crowd sensing, real time mobile health monitoring, mobile social network in proximity and so on. Although recent smartphones are quite capable in terms of mobile data transmission speed and computation power, the frequent usage of high
performance multi-core mobile CPU and the high speed 3G/4G mobile Internet data transmission will quickly drain the battery power of the mobile device. Although numerous previous researchers have tried to overcome the resource intensive issues in mobile embedded service provisioning domain, most of the efforts were constrained because of the underlying resource intensive technologies. This paper presents a lightweight mobile Web service provisioning framework for mobile sensing which utilises the protocols that were designed for constrained Internet of Things environment. The prototype experimental results show that the proposed framework can provide higher throughput and less resource consumption than the traditional mobile Web service frameworks.
LIGHTWEIGHT MOBILE WEB SERVICE PROVISIONING FOR THE INTERNET OF THINGS MEDIATIONijujournal
Emerging sensor-embedded smartphones motivated the mobile Internet of Things research. With the
integrated embedded hardware and software sensor components, and mobile network technologies,
smartphones are capable of providing various environmental context information via embedded mobile
device-hosted Web services (MWS). MWS enhances the capability of various mobile sensing applications
such as mobile crowdsensing, real time mobile health monitoring, mobile social network in proximity and
so on. Although recent smartphones are quite capable in terms of mobile data transmission speed and
computation power, the frequent usage of high performance multi-core mobile CPU and the high speed
3G/4G mobile Internet data transmission will quickly drain the battery power of the mobile device.
Although numerous previous researchers have tried to overcome the resource intensive issues in mobile
embedded service provisioning domain, most of the efforts were constrained because of the underlying
resource intensive technologies. This paper presents a lightweight mobile Web service provisioning
framework for mobile sensing which utilises the protocols that were designed for constrained Internet of
Things environment. The prototype experimental results show that the proposed framework can provide
higher throughput and less resource consumption than the traditional mobile Web service frameworks.
Lightweight Mobile Web Service Provisioning for the Internet of Things Mediat...ijujournal
Emerging sensor-embedded smartphones motivated the mobile Internet of Things research. With the
integrated embedded hardware and software sensor components, and mobile network technologies,
smartphones are capable of providing various environmental context information via embedded mobile
device-hosted Web services (MWS). MWS enhances the capability of various mobile sensing applications
such as mobile crowdsensing, real time mobile health monitoring, mobile social network in proximity and
so on. Although recent smartphones are quite capable in terms of mobile data transmission speed and
computation power, the frequent usage of high performance multi-core mobile CPU and the high speed
3G/4G mobile Internet data transmission will quickly drain the battery power of the mobile device.
Although numerous previous researchers have tried to overcome the resource intensive issues in mobile
embedded service provisioning domain, most of the efforts were constrained because of the underlying
resource intensive technologies. This paper presents a lightweight mobile Web service provisioning
framework for mobile sensing which utilises the protocols that were designed for constrained Internet of
Things environment. The prototype experimental results show that the proposed framework can provide
higher throughput and less resource consumption than the traditional mobile Web service frameworks.
Effective Replicated Server Allocation Algorithms in Mobile computing Systemsijwmn
In mobile environments, mobile device users access and transfer a great deal of data through the online servers. In order to enhance users’ access speed in a wireless network, decentralizing replicated servers appropriately in the network is required. Previous work regarding this issue had focused on the placement of replicated servers along with the moving paths of the users to maximize the hit ratio. When a miss occurs, they simply ignored the file request. Therefore, we suggest a solution to take care of such a miss by sending a file request to a replicated server nearby in the network
Parallel and Distributed System IEEE 2015 ProjectsVijay Karan
List of Parallel and Distributed System IEEE 2015 Projects. It Contains the IEEE Projects in the Domain Parallel and Distributed System for the year 2015
Parallel and Distributed System IEEE 2015 ProjectsVijay Karan
List of Parallel and Distributed System IEEE 2015 Projects. It Contains the IEEE Projects in the Domain Parallel and Distributed System for the year 2015
Automatic Management of Wireless Sensor Networks through Cloud Computingyousef emami
With the faster adoption of wireless sensor networks (WSNs),on the one hand sensor-derived data need to be accessed via various Web-based social networks or virtual communities and on the other hand, limited processing ability of WSNs is a hurdle. To address this issue WSNs can be integrated with cloud. Cloud enjoys ample processing ability andis a capable infrastructure to deliver people-centric and context-aware services to users, thus expedites adoption of WSNs.In this paper anovel framework based on policy based network management is proposed to integrate WSNs with cloud, aimstoautomate and simplifies WSN’smanagement tasks.
Differentiated Classes of Service and Flow Management using An Hybrid Broker1IDES Editor
Recently, mobile networks have been overloaded
with a considerable amount of data traffic. The current paper
proposes a management service for mobile environments,
using policies and quality metrics, which ensure a better usage
of network resources with a more fine-grained management
based on flows with different classes of service and
transmission rates. This management of flows is supported
through a closed innovative control loop among a flexible
brokerage service in the network, and agents at the mobile
terminals. It also allows the terminals to make well-informed
decisions about their connections to enhance the number of
connected flows per technology and the individual service level
offered to each flow. Our results indicate that the proposed
solution optimizes the usage of available 4G network resources
among a high number of differentiated flows in several
scenarios where access technologies are extremely overloaded
whilst protecting, through a low complexity scheme, the flows
associated to users that have celebrated more expensive
contracts with their network operators.
Secure & fault tolerance handoff in vanet using special mobile agentcsandit
Vehicular Traffic poses an emerging issue nowadays. The critical factors for the data
communication are speed and time tradeoffs. For data communication, gathering and retrieving
information many cost-effective and tested techniques are required in VANET. Client server
architectures being coercive are commonly used in spite of having drawbacks of fault and time
in-effectiveness. This paper elaborates a proposed method in VANET for fault tolerance
information retrieval based on theory of bandwidth and timestamp. Mobile Agents, with the
feature of autonomy, social ability, learning, and most importantly mobility, regarded as an
appropriate technology to build applications for instance information retrieval system in mobile
computing environment.
International Journal of Engineering Research and Development (IJERD)IJERD Editor
journal publishing, how to publish research paper, Call For research paper, international journal, publishing a paper, IJERD, journal of science and technology, how to get a research paper published, publishing a paper, publishing of journal, publishing of research paper, reserach and review articles, IJERD Journal, How to publish your research paper, publish research paper, open access engineering journal, Engineering journal, Mathemetics journal, Physics journal, Chemistry journal, Computer Engineering, Computer Science journal, how to submit your paper, peer reviw journal, indexed journal, reserach and review articles, engineering journal, www.ijerd.com, research journals,
yahoo journals, bing journals, International Journal of Engineering Research and Development, google journals, hard copy of journal
Research Inventy : International Journal of Engineering and Scienceinventy
Research Inventy : International Journal of Engineering and Science
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed
New Proposedclassic Cluster Layer Architecture for Mobile Adhoc Network (cclam)CSCJournals
Organization, scalability and routing have been identified as key problems hindering viability and commercial success of mobile ad hoc networks. Clustering of mobile nodes among separate domains has been proposed as an efficient approach to address those issues. In this work, we introduce an efficient distributed clustering layers algorithm that uses location metrics for cluster formation. Our proposed solution mainly addresses cluster stability, manageability issues. Also, unlike existing active clustering methods, our algorithm relieves the network from the unnecessary burden of control messages broadcasting, especially for relatively static network topologies. This is achieved through adapting broadcast period according to mobile nodes mobility pattern. The efficiency, scalability and competence of our algorithm against alternative approaches have been shows in algorithm
Peer to peer cache resolution mechanism for mobile ad hoc networksijwmn
In this paper we investigate the problem of cache resolution in a mobile peer to peer ad hoc network. In our
vision cache resolution should satisfy the following requirements: (i) it should result in low message
overhead and (ii) the information should be retrieved with minimum delay. In this paper, we show that
these goals can be achieved by splitting the one hop neighbours in to two sets based on the transmission
range. The proposed approach reduces the number of messages flooded in to the network to find the
requested data. This scheme is fully distributed and comes at very low cost in terms of cache overhead. The
experimental results gives a promising result based on the metrics of studies
In this paper we explore the issue of store determination in a portable shared specially appointed system. In our vision reserve determination ought to fulfill the accompanying prerequisites: (i) it ought to bring about low message overhead and (ii) the data ought to be recovered with least postponement. In this paper, we demonstrate that these objectives can be accomplished by part the one bounce neighbors into two sets in view of the transmission run. The proposed approach lessens the quantity of messages overflowed into the system to discover the asked for information. This plan is completely circulated and comes requiring little to no effort as far as store overhead. The test comes about gives a promising outcome in view of the measurements of studies.
Synthesis of Non-Replicated Dynamic Fragment Allocation Algorithm in Distribu...IDES Editor
Distributed databases have become the most
essential technology for recent business organizations. In most
of the cases Distributed Databases are developed in a Bottom-
Up approach, fragmentation exists beforehand. The optimum
allocation of those fragments is the only way, which can be
exploited by the designers to increase the performance,
efficiency, reliability and availability of the Distributed
Database in the realistic dynamic environment, where the access
probabilities of nodes to fragments change over time. In this
paper, a new dynamic fragment allocation algorithm is
proposed in Non-Replicated allocation scenario, which
incorporates the time constraints of database accesses, volume
threshold and the volume of data transmitted in successive time
intervals to dynamically reallocate fragments to sites at runtime
in accordance with the changing access patterns. It will migrate
a fragment to a particular site only when that site has made
data transfer higher than all other sites and greater than the
threshold value from or to that fragment consistently in some
recent time intervals. The choice of the volume threshold, the
number of time intervals and the duration of each time interval
are the most important factors which regulate the frequency
of fragment reallocations. The proposed algorithm will decrease
the movement of fragments over the network and data transfer
cost and will also improve the overall performance of the system
by dynamically allocating fragments in a most optimum and
intuitive manner.
A MARKOVIAN MODEL FOR INTERNET OF THINGS APPLICATIONIJCNCJournal
Internet of Things (IoT) allows communication among human-to-things, things-to-human, and things-tothings that are incorporated into an information networks allowing automatic information interchange and
the processing of data at real time. In this paper, we conduct a performance analysis of a real application
defined through four traffic classes with the priorities present in smart cities using Continuous Time
Markov Chains(CTMC). Based on a finite capacity queuing system, we propose a new cost-effective
analytical model with a push-out management scheme in favor of the highest priority (emergency) traffic.
Based on the analytical model, several performance measures for different traffic classes have been
studiedextensively including blocking probability; push out probability, delay, channel utilization as well as
overall system performance.
Adaptive Offloading in Mobile Cloud Computing by automatic partitioning approach of tasks is the idea to augment execution through migrating heavy computation from mobile devices to resourceful cloud servers and then receive the results from them via wireless networks. Offloading is an effective way to
overcome the resources and functionalities constraints
of the mobile devices since it can release them from
intensive processing and increase performance of the
mobile applications, in terms of response time.
Offloading brings many potential benefits, such as
energy saving, performance improvement, reliability
improvement, ease for the software developers and
better exploitation of contextual information.
Parameters about method transitions, response times,
cost and energy consumptions are dynamically reestimated
at runtime during application executions.
A Survey on the Common Network Traffic Sources ModelsCSCJournals
Selecting the appropriate traffic model can lead to the successful design of networks. The more accurate is the traffic model the better is the system quantified in terms of its performance Successful design lead to enhancement the overall performance of the whole of network .in literature there is innumerous traffic models proposed for understanding and analyzing the traffic characteristics of networks. Consequently, the study of traffic models to understand the features of the models and identify eventually the best traffic model, for a concerned environment has become a crucial and lucrative task. Good traffic modeling is also a basic requirement for accurate capacity planning. This paper provides an overview of some of the widely used network traffic models, highlighting the core features of the model and traffic characteristics they capture best. Finally we found that the N_BURST traffic model can capture the traffic characteristics of most types of networks, under every possible circumstance rather than any type of traffic model.
LIGHTWEIGHT MOBILE WEB SERVICE PROVISIONING FOR THE INTERNET OF THINGS MEDIATIONijujournal
Emerging sensor-embedded smartphones motivated the mobile Internet of Things research. With the integrated embedded hardware and software sensor components, and mobile network technologies, smartphones are capable of providing various environmental context information via embedded mobile device-hosted Web services (MWS). MWS enhances the capability of various mobile sensing applications such as mobile crowd sensing, real time mobile health monitoring, mobile social network in proximity and so on. Although recent smartphones are quite capable in terms of mobile data transmission speed and computation power, the frequent usage of high
performance multi-core mobile CPU and the high speed 3G/4G mobile Internet data transmission will quickly drain the battery power of the mobile device. Although numerous previous researchers have tried to overcome the resource intensive issues in mobile embedded service provisioning domain, most of the efforts were constrained because of the underlying resource intensive technologies. This paper presents a lightweight mobile Web service provisioning framework for mobile sensing which utilises the protocols that were designed for constrained Internet of Things environment. The prototype experimental results show that the proposed framework can provide higher throughput and less resource consumption than the traditional mobile Web service frameworks.
LIGHTWEIGHT MOBILE WEB SERVICE PROVISIONING FOR THE INTERNET OF THINGS MEDIATIONijujournal
Emerging sensor-embedded smartphones motivated the mobile Internet of Things research. With the
integrated embedded hardware and software sensor components, and mobile network technologies,
smartphones are capable of providing various environmental context information via embedded mobile
device-hosted Web services (MWS). MWS enhances the capability of various mobile sensing applications
such as mobile crowdsensing, real time mobile health monitoring, mobile social network in proximity and
so on. Although recent smartphones are quite capable in terms of mobile data transmission speed and
computation power, the frequent usage of high performance multi-core mobile CPU and the high speed
3G/4G mobile Internet data transmission will quickly drain the battery power of the mobile device.
Although numerous previous researchers have tried to overcome the resource intensive issues in mobile
embedded service provisioning domain, most of the efforts were constrained because of the underlying
resource intensive technologies. This paper presents a lightweight mobile Web service provisioning
framework for mobile sensing which utilises the protocols that were designed for constrained Internet of
Things environment. The prototype experimental results show that the proposed framework can provide
higher throughput and less resource consumption than the traditional mobile Web service frameworks.
Lightweight Mobile Web Service Provisioning for the Internet of Things Mediat...ijujournal
Emerging sensor-embedded smartphones motivated the mobile Internet of Things research. With the
integrated embedded hardware and software sensor components, and mobile network technologies,
smartphones are capable of providing various environmental context information via embedded mobile
device-hosted Web services (MWS). MWS enhances the capability of various mobile sensing applications
such as mobile crowdsensing, real time mobile health monitoring, mobile social network in proximity and
so on. Although recent smartphones are quite capable in terms of mobile data transmission speed and
computation power, the frequent usage of high performance multi-core mobile CPU and the high speed
3G/4G mobile Internet data transmission will quickly drain the battery power of the mobile device.
Although numerous previous researchers have tried to overcome the resource intensive issues in mobile
embedded service provisioning domain, most of the efforts were constrained because of the underlying
resource intensive technologies. This paper presents a lightweight mobile Web service provisioning
framework for mobile sensing which utilises the protocols that were designed for constrained Internet of
Things environment. The prototype experimental results show that the proposed framework can provide
higher throughput and less resource consumption than the traditional mobile Web service frameworks.
Effective Replicated Server Allocation Algorithms in Mobile computing Systemsijwmn
In mobile environments, mobile device users access and transfer a great deal of data through the online servers. In order to enhance users’ access speed in a wireless network, decentralizing replicated servers appropriately in the network is required. Previous work regarding this issue had focused on the placement of replicated servers along with the moving paths of the users to maximize the hit ratio. When a miss occurs, they simply ignored the file request. Therefore, we suggest a solution to take care of such a miss by sending a file request to a replicated server nearby in the network
Parallel and Distributed System IEEE 2015 ProjectsVijay Karan
List of Parallel and Distributed System IEEE 2015 Projects. It Contains the IEEE Projects in the Domain Parallel and Distributed System for the year 2015
Parallel and Distributed System IEEE 2015 ProjectsVijay Karan
List of Parallel and Distributed System IEEE 2015 Projects. It Contains the IEEE Projects in the Domain Parallel and Distributed System for the year 2015
Automatic Management of Wireless Sensor Networks through Cloud Computingyousef emami
With the faster adoption of wireless sensor networks (WSNs),on the one hand sensor-derived data need to be accessed via various Web-based social networks or virtual communities and on the other hand, limited processing ability of WSNs is a hurdle. To address this issue WSNs can be integrated with cloud. Cloud enjoys ample processing ability andis a capable infrastructure to deliver people-centric and context-aware services to users, thus expedites adoption of WSNs.In this paper anovel framework based on policy based network management is proposed to integrate WSNs with cloud, aimstoautomate and simplifies WSN’smanagement tasks.
Differentiated Classes of Service and Flow Management using An Hybrid Broker1IDES Editor
Recently, mobile networks have been overloaded
with a considerable amount of data traffic. The current paper
proposes a management service for mobile environments,
using policies and quality metrics, which ensure a better usage
of network resources with a more fine-grained management
based on flows with different classes of service and
transmission rates. This management of flows is supported
through a closed innovative control loop among a flexible
brokerage service in the network, and agents at the mobile
terminals. It also allows the terminals to make well-informed
decisions about their connections to enhance the number of
connected flows per technology and the individual service level
offered to each flow. Our results indicate that the proposed
solution optimizes the usage of available 4G network resources
among a high number of differentiated flows in several
scenarios where access technologies are extremely overloaded
whilst protecting, through a low complexity scheme, the flows
associated to users that have celebrated more expensive
contracts with their network operators.
Secure & fault tolerance handoff in vanet using special mobile agentcsandit
Vehicular Traffic poses an emerging issue nowadays. The critical factors for the data
communication are speed and time tradeoffs. For data communication, gathering and retrieving
information many cost-effective and tested techniques are required in VANET. Client server
architectures being coercive are commonly used in spite of having drawbacks of fault and time
in-effectiveness. This paper elaborates a proposed method in VANET for fault tolerance
information retrieval based on theory of bandwidth and timestamp. Mobile Agents, with the
feature of autonomy, social ability, learning, and most importantly mobility, regarded as an
appropriate technology to build applications for instance information retrieval system in mobile
computing environment.
SECURE & FAULT TOLERANCE HANDOFF IN VANET USING SPECIAL MOBILE AGENTcscpconf
Vehicular Traffic poses an emerging issue nowadays. The critical factors for the data communication are speed and time tradeoffs. For data communication, gathering and retrieving
information many cost-effective and tested techniques are required in VANET. Client server architectures being coercive are commonly used in spite of having drawbacks of fault and time in-effectiveness. This paper elaborates a proposed method in VANET for fault tolerance information retrieval based on theory of bandwidth and timestamp. Mobile Agents, with the
feature of autonomy, social ability, learning, and most importantly mobility, regarded as an appropriate technology to build applications for instance information retrieval system in mobile computing environment.
PERFORMANCE EVALUATION OF VERTICAL HARD HANDOVERS IN CELLULAR MOBILE SYSTEMSijngnjournal
With the rapid increase of new and diverse cellular mobile services, the overlapping of cells has become typical in the majority of the coverage area of the network. Vertical handovers occur between two layers of cells when a user is switched from one layer to the other. In this paper we investigate the influence of network parameters on vertical hard handover performance in a cell environment. The work considers two layers of cells: a layer of macrocells and a layer of microcells. Handover requests enter the macrocell from neighbor macrocells and from microcells that belong to a different layer. Using Markov chain analysis and simulation we calculate network performance parameters such as mean queue delay, handover dropping probability and channel utilization. We also compare the handover performance for the macrocell and macrocell traffic separately. Our results show the influence of total channels, maximum queue size and handover request arrival rate on handover performance. They also show that when the traffic from each layer is treated with equal priority in the system, the performance of each layer is comparable.
Performance Evaluation of Vertical Hard Handovers in Cellular Mobile Systemsjosephjonse
With the rapid increase of new and diverse cellular mobile services, the overlapping of cells has become typical in the majority of the coverage area of the network. Vertical handovers occur between two layers of cells when a user is switched from one layer to the other. In this paper we investigate the influence of network parameters on vertical hard handover performance in a cell environment. The work considers two layers of cells: a layer of macrocells and a layer of microcells. Handover requests enter the macrocell from neighbor macrocells and from microcells that belong to a different layer. Using Markov chain analysis and simulation we calculate network performance parameters such as mean queue delay, handover dropping probability and channel utilization. We also compare the handover performance for the macrocell and macrocell traffic separately. Our results show the influence of total channels, maximum queue size and handover request arrival rate on handover performance. They also show that when the traffic from each layer is treated with equal priority in the system, the performance of each layer is comparable.
Performance Evaluation of Vertical Hard Handovers in Cellular Mobile Systemsjosephjonse
With the rapid increase of new and diverse cellular mobile services, the overlapping of cells has become typical in the majority of the coverage area of the network. Vertical handovers occur between two layers of cells when a user is switched from one layer to the other. In this paper we investigate the influence of network parameters on vertical hard handover performance in a cell environment. The work considers two layers of cells: a layer of macrocells and a layer of microcells. Handover requests enter the macrocell from neighbor macrocells and from microcells that belong to a different layer. Using Markov chain analysis and simulation we calculate network performance parameters such as mean queue delay, handover dropping probability and channel utilization. We also compare the handover performance for the macrocell and macrocell traffic separately. Our results show the influence of total channels, maximum queue size and handover request arrival rate on handover performance. They also show that when the traffic from each layer is treated with equal priority in the system, the performance of each layer is comparable.
PERFORMANCE EVALUATION OF VERTICAL HARD HANDOVERS IN CELLULAR MOBILE SYSTEMSjosephjonse
With the rapid increase of new and diverse cellular mobile services, the overlapping of cells has become typical in the majority of the coverage area of the network. Vertical handovers occur between two layers of cells when a user is switched from one layer to the other. In this paper we investigate the influence of network parameters on vertical hard handover performance in a cell environment. The work considers two layers of cells: a layer of macrocells and a layer of microcells. Handover requests enter the macrocell from neighbor macrocells and from microcells that belong to a different layer. Using Markov chain analysis and simulation we calculate network performance parameters such as mean queue delay, handover dropping probability and channel utilization. We also compare the handover performance for the macrocell and macrocell traffic separately. Our results show the influence of total channels, maximum queue size and handover request arrival rate on handover performance. They also show that when the traffic from each layer is treated with equal priority in the system, the performance of each layer is comparable.
PERFORMANCE EVALUATION OF VERTICAL HARD HANDOVERS IN CELLULAR MOBILE SYSTEMSijngnjournal
With the rapid increase of new and diverse cellular mobile services, the overlapping of cells has become typical in the majority of the coverage area of the network. Vertical handovers occur between two layers of cells when a user is switched from one layer to the other. In this paper we investigate the influence of network parameters on vertical hard handover performance in a cell environment. The work considers two layers of cells: a layer of macrocells and a layer of microcells. Handover requests enter the macrocell from neighbor macrocells and from microcells that belong to a different layer. Using Markov chain analysis and simulation we calculate network performance parameters such as mean queue delay, handover dropping probability and channel utilization. We also compare the handover performance for the macrocell and macrocell traffic separately. Our results show the influence of total channels, maximum queue size and handover request arrival rate on handover performance. They also show that when the traffic from each layer is treated with equal priority in the system, the performance of each layer is comparable.
Use of Hidden Markov Mobility Model for Location Based ServicesIJERA Editor
These days people prefer to use portable and wireless devices such as laptops, mobile phones, They are connected through satellites. As user moves from one point to other, task of updating stored information becomes difficult. Provision of Location based services to users, faces some challenges like limited bandwidth and limited client power. To optimize data accessibility and to minimize access cost, we can store frequently accessed data item in cache of client. So small size of cache is introduced in mobile devices. Data fetched from server is stored on cache. So requested data from user is provided from cache and not from remote server. Question arises that which data should be kept in the cache? Performance of cache majorly depends on the cache replacement policies which select data suitable for eviction from cache. This paper presents use of Hidden Markov Models(HMMs) for prediction of user‟s future location. Then data item irrelevant to this predicted location is fetched out from the cache. The proposed approach clusters location histories according to their location characteristics and also it considers each user‟s previous actions. This results in producing high packet delivery ratio and minimum delay.
Management of context aware software resources deployed in a cloud environmen...ijdpsjournal
In cloud computing environments, context information is continuously created by context providers and
consumed by the applications on mobile devices. An important characteristic of cloud-based context aware
services is meeting the service level agreements (SLAs) to deliver a certain quality of service (Qos), such as
guarantees on response time or price. The response time to a request of context-aware software is affected
by loading extensive context data from multiple resources on the chosen server. Therefore, the speed of
such software would be decreased during execution time. Hence, proper scheduling of such services is
indispensable because the customers are faced with time constraints. In this research, a new scheduling
algorithm for context aware services is proposed which is based on classifying similar context consumers
and dynamically scoring the requests to improve the performance of the server hosting highly-requested
context-aware software while reducing costs of cloud provider. The approach is evaluated via simulation
and comparison with gi-FIFO scheduling algorithm. Experimental results demonstrate the efficiency of the
proposed approach.
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Performance evaluation of transaction processing in mobile data base systems
1. International Journal of Database Management Systems ( IJDMS ) Vol.6, No.2, April 2014
DOI : 10.5121/ijdms.2014.6202 19
PERFORMANCE EVALUATION OF
TRANSACTION PROCESSING IN MOBILE DATA
BASE SYSTEMS
Ahmad Al-Qerem
Department of Computer Science, Zarqa University, Zarqa, Jordan
ABSTRACT
Specific characteristics of mobile environments make traditional transaction management techniques no
longer appropriate. This is due the fact that the ACID properties of transactions are not simply followed, in
particular the consistency property. Thus, transaction management models adopting weaker form of
consistency are needed and these models can now tolerate a limited amount of consistency. In this paper
we evaluate our execution framework on different mobile computation modes using different execution
strategies. Moreover, the effects of the fixed host transaction are identified and included in the evaluation
The integration between wired and wireless environments confirms that the execution strategy is critical for
the performance of a system. Neither MHS nor FHS are optimal in all situations and the performance
penalties and wasted wireless resources can be substantial. A combined strategy CHS over MCA-FSA
computation model matches the best performance of the FHS and MHS and shows better performance than
both in many cases.
KEYWORDS
Mobile Data Base, transaction processing, Execution Strategies, Execution framework, Performance
evaluation.
1. INTRODUCTION
Mobile computing suggest that there will be more competition for shared data since it provides
users with ability to access information and services through wireless connections that can be
retained even while the user is moving. Further, mobile users will have to share their data with
others. Those users may have access to the shared data by reliable wired communication (i.e.
fixed host transaction or unreliable wireless communication (i.e. mobile host transaction). The
task of ensuring consistency of shared data becomes more difficult in mobile computing because
of limitations of wireless communication and restrictions imposed due to mobility and portability
[20]. The access to the future information systems through mobile computers will be performed
with the help of mobile transactions. Research in mobile database systems (MDBS) has received
a lot of interests in the past decade [1, 16, 19, 24, 25, 26, 28, and 29]. Transactions in a mobile
database system are usually associated with relaxation of ACID properties because of its long-
lived nature and the limitation inherited from the wireless environment. Any abortion of a mobile
transaction may result in a high cost associated with scarce wireless resources, while fixed
transactions might only cause a little degraded level of system performance. In the past two
decades, researchers have proposed various transaction models [13, 23,21] either to tackle the
isolation and atomicity properties of mobile transaction [13, 23, 27 ] or guarantee the consistency
of mobile transaction Most of the previous studies in mobile database system often assume that
the system may consist of only one single type of transaction(i.e. mobile transaction). Without
2. International Journal of Database Management Systems ( IJDMS ) Vol.6, No.2, April 2014
20
paying any attention to the effect of interaction between both types of transactions being shared
the same databases simultaneously. Different assumptions have been made on the system and
transaction models, e.g., the execution strategy and structures of the transaction, such that
different scheduling techniques can be engineered to satisfy the different requirements of mobile
transactions. However, little work has been done in the development of an integrated approach
that can handle a MDBS satisfactorily where a mixed population of fixed and mobile transactions
exists simultaneously. However, for many MDBS applications, such a mixture of workloads is
very common [31]. It is very important that execution strategies designed for mobile transactions
are evaluated in such mixture. In this paper an execution frame work is propose we investigate the
effects of such interaction on the mobile resources under different execution strategies. In section
2 we show the difference between transaction in mobile environment and traditional transaction ,
section 3 describe the mobile database architecture, section 4 compare between three execution
strategies, section 5 present the execution frame work used to compare the strategies, section 5
describe the simulation model, system’s parameter and discuss the result, section 6 conclude our
work.
2. MOBILE TRANSACTION PROCESSING
A transaction in mobile environment is different than the transactions in the centralized or
distributed databases in the following ways.
1. The mobile transactions might have to split their computations into sets of operations,
some of which execute on mobile host while others on stationary host. A mobile
transaction shares their states and partial results with other transactions due to
disconnection and mobility.
2. The mobile transactions require computations and communications to be supported by
stationary hosts.
3. When the mobile user moves during the execution of a transaction, it continues its
execution in the new cell. The partially executed transaction may be continued at the
fixed local host according to the instruction given by the mobile user. Different
mechanisms are required if the user wants to continue its transaction at a new destination.
4. As the mobile hosts move from one cell to another, the states of transaction, states of
accessed data objects, and the location information also move.
5. The mobile transactions are long-lived transactions due to the mobility of both the data
and users, and due to the frequent disconnections.
6. The mobile transactions should support and handle concurrency, recovery, disconnection
and mutual consistency of the replicated data objects.
To support mobile transactions, the transaction processing models should accommodate the
limitations of mobile computing, such as unreliable communication, limited battery life, low
bandwidth communication, and reduced storage capacity. Mobile computations should minimize
aborts due to disconnection. Operations on shared data must ensure correctness of transactions
executed on both stationary and mobile hosts. The blocking of a transaction's executions on either
the stationary or mobile hosts must be minimized to reduce communication cost and to increase
concurrency. Proper support for mobile transactions must provide for local autonomy to allow
transactions to be processed and committed on the mobile host despite temporary disconnection.
Semantic based transaction processing models [1, 9] have been extended for mobile computing in
[10] to increase concurrency by exploiting commutative operations. These techniques require
caching large portion of the database or maintain multiple copies of many data items. In [10],
fragmentability of data objects has been used to facilitate semantic based transaction processing
in mobile databases. The scheme fragments data objects. Each fragmented data object has to be
cached independently and manipulated synchronously. That is, on request, a fragment of data
3. International Journal of Database Management Systems ( IJDMS ) Vol.6, No.2, April 2014
21
object is dispatched to the MU. On completion of the transaction, the mobile hosts return the
fragments to the BS. Fragments are then integrated in the object in any order and such objects are
termed as reorderable objects. This scheme works only in the situations where the data objects
can be fragmented like sets, stacks and queues. In [11], the concept of transaction proxies is
introduced to support recovery. For each transaction submitted at an MU, a dual transaction
called proxy is submitted to the base station. The proxy transaction includes the updates of the
original transaction. Proxy transaction takes the periodic backup of the computation performed at
mobile host. Similar to above, in [12], the notion of twin-transaction was introduced which
essentially replicate the process of executing transactions. In twin transaction model, each writ’s
request will be mirrored and two equivalent transactions will be created. In this way, if a mobile
host is disconnected, the transaction execution can still be proceed. In [11], disconnection was not
discussed. Dynamic object clustering has been proposed in mobile computing in [8, 13]. It
assumes a fully distributed system, and the transaction model is designed to maintain the
consistency of the database. The model uses weak read, weak-write, strict-read and strict-write.
The decomposition of operations is done based on the consistency requirement. Strict-read and
strict-write have the same semantics as normal read and write operations invoked by transactions
satisfying ACID properties. A weak-read returns the value of a locally cached object written by a
strict-write or a weak-write. A weak-write operation only updates a locally cached object, which
might become permanent on cluster merging if the weak-write does not conflict with any strict-
read or strict-write operation. The weak transactions use local and global commits. The local
commit is same as pre-commit of [6] and global commit is same as final commit of [14].
However, a weak transaction after local commit can abort and is compensated. In [14], a pre-
committed transaction does not abort; hence require no undo or compensation. A weak
transaction's updates are visible to other weak transactions whereas prewrites are visible to all
transactions. [4] Present a new transaction model using isolation-only transactions (IOT). The
model supports a variety of mechanisms for automatic conflict detection and resolution. IOTs are
sequences of file accesses that unlike traditional transactions have only isolation property.
Transaction execution is performed entirely on the client and no partial result is visible on the
servers. IOTs do not provide failure atomicity, and only conditionally guarantee permanence.
They are similar to weak transactions of [8]. An open nested transaction model has been proposed
in [2] for modelling mobile transactions as a set of subtransactions. They introduce reporting and
co-transactions. A reporting transaction can share its partial results, can execute concurrently and
can commit independently. Co-transactions are like co-routines and are not executed
concurrently. The model allows transactions to be executed on disconnection. It also supports
unilateral commitment of subtransactions, compensating and non-compensatable transactions.
The author claims that the model minimizes wired as well as wireless communication cost.
However, not all the operations are compensated [2], and compensation is costly in mobile
computing. Transaction models for mobile computing that perform updates at mobile computers
have been developed in [15, 8]. These efforts propose a new correctness criterion [2] that is
weaker than the serializability. They can cope more efficiently with the restrictions of mobile and
wireless communications. In [14, 16.17], we look mobile transaction more as a concurrency
control problem and provide database consistency. We incorporate a prewrite operation [5] before
a write operation in a mobile transaction to improve data availability. A prewrite operation does
not update the state of a data object but only makes visible the value that the data object will have
after the commit of the transaction. Once a transaction received all the values read and declares
all the prewrites, it can pre-commit at mobile host (i.e., computer connected to unreliable
communication) and the remaining transaction's execution is shifted to the stationary host (i.e.,
computer connected to the reliable fixed network). Writes on database, after pre-commit, take
time and resources at stationary host and are therefore, delayed. This reduces network traffic
congestion. A precommitted transaction's prewrite values are made visible both at mobile and
stationary hosts before the final commit of the transaction. This increases data availability during
frequent disconnection common in mobile computing. Since the expensive part of the
transaction's execution is shifted to the stationary host, it reduces the computing expenses (e.g.,
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battery, low bandwidth, memory etc.) at mobile host. Since a pre-committed transaction does not
abort, no undo recovery needs to be performed in our model. A mobile host can cache only
prewrite values of the data objects, which will take less space, time, and energy and can be
transmitted over low bandwidth. A kangaroo transaction (KT) model was given in [3]. It
incorporates the property that transactions in a mobile computing hop from a base station to
another as the mobile unity moves. The mobility of the transaction model is captured by the use
of split transaction [18]. A split transaction divides on going transactions into serializable
subtransactions. Earlier created subtransaction is committed and the second subtransaction
continues its execution. The mobile transaction is split when a hop occurs. The model captures
the data behaviour of the mobile transaction using global and local transactions. The model also
relies on compensating transaction in case a transaction aborts. The model in [6]has the option of
either using nested transactions or split transactions. However, the save point or split point of a
transaction is explicitly defined by the use of pre-commit. This feature of the model allows the
split point to occur in any of the cell. Unlike KT model, the earlier subtransaction after pre-
commit can still continue its execution with the new subtransaction since their commit orders in
the model [6]are based on pre-commit point. Unlike KT, the model in [6] does not need any
compensatory transaction. In [7], a distributed lock management scheme is presented. It allows a
read unlock for an item to be executed at any copy site of that item; the site may be different from
the copy site on which read lock is set. The proposed scheme utilizes the replicated copies of data
items to reduce the message cost incurred by the mobility of the transaction host. In a
multidatabase environment with mobile computers involved, the nature of computing is such that
the user may not wait for the submitted global transaction to complete before disconnected from
the network. In [19], a basic architectural framework to support transaction management is
multidatabase systems is proposed and discussed. A simple message and queuing facility is
suggested which provides a common communication and data exchange protocol to effectively
manage global transactions submitted by mobile workstations. The state of global transactions is
modelled through the use of subqueues. The proposed strategy allows mobile workstations to
submit global transactions and then disconnected itself from the network to perform some other
tasks thereby increasing processing parallelism and independence. A transaction management
model for the mobile multidatabase is presented in [7], called toggle transaction management
technique. Here site transactions are allowed to commit independently and resources are released
in timely manner. A toggle operation is used to minimize the ill-effects of the prolonged
execution of long-lived transaction.
3. MOBILE DATABASE ARCHITECTURE
As discussed in previous section, there can be different models for mobile computing systems.
Among them, we choose the model most likely to be a computing environment for mobile
database systems. In the system, some computers are fixed and some are mobile. Among the
mobile computers, some play the role of mobile clients and some the role of mobile hosts. This
architecture is widely accepted in existing research for mobile database applications [2], where a
global database is distributed among the fixed network nodes. An example of such architecture is
shown Figure 1. In this system architecture, all the network nodes in the wired part are
fixed units. Mobile units retain communication through the wireless links. Some fixed units,
called base stations or mobile support stations, have special functionality with a wireless interface
to communicate with mobile units. Each mobile station provides networking services for all the
mobile units within a given geographic area called cell. In other words, each cell has a base
station and mobile units within that cell access data on remote nodes through the local base
station.
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Figure 1. Architecture of mobile database systems
A global database (GDB) is defined as a finite set of data items. A GDB is partitioned
among fixed hosts as well as mobile hosts (GDB = MDBU FDB). Where the data items on fixed
hosts make up the fixed database (FDB) of the GDB (i.e. FDB = iFDBU
) and the data items
on mobile hosts make up the mobile database (MDB) of the GDB (i.e. MDB = iMDBU
).
Moreover, the data items on a single mobile host are called a mobile part of the MDB.
Accordingly, a data item in the FDB is referred to as a fixed data item and a data item in the
MDB is referred to as a mobile data item. Furthermore, each data item has one primary copy and
thus one owner. Only its owner can update the primary copy of a data item. A data item in the
MDB is owned by a mobile host and a data item in the FDB is owned by a fixed host. We further
assumed that each mobile host has local storage and computing capability, and is able to estimate
and exchange its status regarding the mobility information. The fixed data items are replicated by
caching on a mobile host, whereas the mobile data items have a full replication on a fixed host.
Moreover, a mobile transaction does not access the data on other mobile units (MDBi I MDBj
=ϕ for all i, j such that i ≠ j). That is, it can access only local mobile data items and fixed data
items.
4. EXECUTION STRATEGIES
4.1. Fixed Host Execution Strategy (FHS)
In this strategy the execution of mobile transactions with a copy of required data on the mobile
unit is transferred to the fixed host. The fixed host coordinates the execution of the transaction on
behalf of the mobile host and returns the final results back to the mobile unit. As such, a mobile
transaction can be processed just like a traditional distributed transaction in a client server model.
The only difference is that the propagation of updates and the return of results to a mobile host
may be delayed as a consequence of wireless communication. This execution strategy is relatively
simple. Its main advantages are:(1) maintaining strict data consistency because an entire
transaction is managed and Executed on fixed host, traditional transaction schemes can be
applied, (2) reducing battery consumption because the operations are shifted to the fixed network,
computation tasks on a mobile host are avoided and (3) the level of concurrency at the fixed host
is increased due to avoidance of long delays result form poor Communication. However, a
shortcoming of fixed host execution strategy is that no autonomous operations are allowed during
the disconnection of a mobile unit because required data on the fixed host is not available. This
policy is suitable when the entire database is allocated on the fixed machines. In other words, a
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mobile host only plays the role of a client, or a remote device. This strategy has been taken an
underlying assumption, of the processing model, by many researchers.
4.2. Mobile Host Execution Strategy (MHS)
To allow continuous computation when a disconnection occurs, the data stored at the fixed hosts
can be duplicated on a mobile unit rather than moving data to a fixed host. Instead of making a
full replication on a local disk, using cached copies is a common technique to support
autonomous operations, increase the availability [14], and minimize network access. Since data
involved in a mobile transaction is always locally available, this policy allows transaction
processing independent of fixed data services. Hence, the autonomous operations can be carried
out at the mobile unit. In addition, this policy uses less battery power compared to the FHS
strategy, regarding data transmission, because the network connection between a mobile unit and
a fixed host is asymmetric. A fixed host typically has a stronger transmitter and unlimited power.
Therefore, transporting data from a fixed host to a mobile unit is likely to be more efficient than
transporting data in the opposite direction. There are two method of transporting data. Firstly, in
planned mode. In this mode required data is transferred from fixed hosts to a mobile unit before a
disconnection occurs. This mode requires that a disconnection protocol knows which data will be
used in the near future. Secondly, non planned mode. In this mode, data is downloaded based on
current transaction requirements and network conditions. For instance, if a transaction uses data
items X and Y, and at this time point the bandwidth is high, then the data will be transferred to
the mobile unit. Considering two types of disconnection, the first mode is more suitable for
predictable disconnection, while the second mode is suitable for unpredictable disconnection.
4.3. Combined Execution Strategy (CHS)
For mobile transactions having a number of subtransactions which pass through different
resources availability during their execution life time, neither MHS nor FHS on its own can give
better performance in terms of system throughput and battery consumption in al1 situations. Since
the conditions of the mobile environment are dynamically reflected in the transaction processing,
an adaptive approach to control the execution of a transaction is desirable. Once that takes fixed
host and mobile host execution strategies as two basic options for each subtransaction, a decision
is made for a given transaction request based on available mobility information to select a specific
execution strategy for each subtransaction of the same mobile transaction in an optimal way
corresponding to the current mobile computing environment. With the combined strategy, a
mobile subtransaction can be scheduled with a data request or a transaction request. In this
approach we can gain two main advantages: (1) a mobile transaction can be tentatively committed
based on locally cached data and other transactions can be submitted during disconnection so that
autonomous operations can be supported. (2) A mobile transaction can be either executed on a
mobile host or a fixed host based on a run-time decision.
5. EXECUTION FRAMEWORK
There have been many different models proposed for Mobile Transactions (MT) [2]. In these
models mobile transaction supposed to be decomposed in to set of subtransaction which make it
possible for the atomicity to be relaxed. The common base between these models their extension
of advanced transaction models. Since our work here is concentrate on evaluating execution
strategies under different network connectivity conditions rather than evaluating a specific mobile
transaction model. We make a general assumption that a mobile transaction MT is defined as a
set of mobile subtransactions. The update made by a subtransaction at the execution place should
be reflected on the opposite part of the network. (I.e. if the execution takes place at the mobile
host, the update made should be reflected on the fixed host and vice versa). So each mobile
subtransaction SMT is decomposed into two subtransactions: namely, a basic subtransaction Tb
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and a complementary subtransaction Tc. Corresponding to this, there are two commit points:
local commit and global commit, respectively. A local commit records the status of all basic
subtransaction processing when their processing is done, as it may not be possible for their
complementary sub-transactions to be issued due to network disconnection at this time. A global
commit implies that all complementary subtransaction has been executed and modified data items
have been propagated to their master copies. Global commit can happen only when the network
is connected. Successful commitment of a mobile transaction occurs if and only if their basic and
complementary sub transactions are successfully committed. So the processing of each mobile
subtransaction consists of two phases, a basic subtransactions executes in the first phase of
processing a mobile subtransaction. Major transaction operations are performed in this phase. A
complementary subtransaction derived from a basic subtransaction and occurs in the second
phase of mobile subtransaction processing and its execution takes place when the data items on
both the fixed part and mobile part are connected. A complementary subtransaction largely
performs updates on the data items that are modified by its basic subtransaction and the place
where a basic subtransaction executes is always opposite to the one where its complementary
subtransaction does. In general each subtransaction of mobile transactions is scheduled as a data
request or a transaction request. The basic subtransaction of a data request transaction is
processed on a mobile transaction host with cached data from the fixed part. The corresponding
complementary subtransaction is processed on a fixed host. Conversely, the basic subtransaction
of a transaction request is processed on a fixed host with the replication of the data items from the
mobile host. The matching complementary subtransaction is processed on the mobile host. In this
way, the effect of data modification can be propagated to its master copy. When a mobile
subtransaction is issued from a mobile host, its basic subtransaction is processed with cached data
if network connectivity between the mobile transaction host and its local base station is
unsatisfactory (i.e., poor bandwidth or disconnected). If the required data is not available, the
transaction is aborted, otherwise after completed; a complementary subtransaction is issued and
put into a queue. When the mobile transaction host restores its connection, the queued
complementary sub transactions are first submitted through a base station to a fixed host. If a
complementary subtransaction fails, the mobile subtransaction is aborted: otherwise it should be
waiting for global commitment. If network connectivity is high a mobile transaction is started.
The location where its basic subtransaction is processed depends on the execution strategy see
Figure 2(a-c)
(a) MHS strategy (b) FHS strategy (c) CHS strategy
Figure.2 Execution Framework for the three strategies
If the decision is made to use a data request, the fixed data items required by the transaction are
downloaded from the fixed host (the size of downloaded data is determined by the amount of
valid data in the cache of the mobile transaction host). After this, the process of mobile
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transaction processing is similar to the one above when network connectivity is poor. On the
other hand, if the decision is made to use a transaction request. The mobile data items required by
the transaction are uploaded from a mobile part owned by the mobile transaction host, to a fixed
host, where the basic subtransaction is processed. Similarly, at this time, if network connectivity
between the mobile transaction host and its local base station is below some threshold, the
complementary subtransaction will be queued and executed later when network connectivity is
improved. If network connectivity remains strong, the complementary subtransaction that
performs updates of mobile data items on the mobile transaction host can be issued as soon as the
basic subtransaction is completed. The execution of mobile transaction can be described as
pseudo code in Figure 3.
Mobile transaction Processing
Begin
For each mobile subtransaction MST
Mobile host analyzes the subtransaction MST to build Tbasic and Tcomplemnetary based on its read and write
requests and cash status (we assume that MH has some server capability).
If the subtransaction T is scheduled as D-req transaction then
Begin
For all data item reads and writes by Tbasic, if Di not in the MDBi cash, MH sends a request to MTM for all
the required read values and request for lock. After MTM acquires the necessary locks, it returns values to
MH. Execute the basic transaction on the MH and send Tcomplementary to be executed on the fixed host.
End
Else if the subtransaction T is scheduled as T-req transaction then
Begin
For all data item reads and writes by Tbasic ∈MDBi
MH sends a request to MTM for all operation with data items Di ∈MDBi required by these operations.
After MTM acquires the necessary read locks, Execute the basic transaction on the FH and send
TComplementary to the mobile host.
End
If all mobile subtransactions successfully finish their execution then
Mobile transaction is committed
End
Figure.3 Mobile Transaction Processing Algorithm
6. COMPUTATION MODEL
The frame work adopted in this paper could be used in different mobile computing models. There
is many computing model found in the literature; in [32] the author restrict the computation
models to a five model and a comparative study based on the ability to deal with mobility
dimension is proposed. Actually our framework can be utilized in the first three computation
models explained as follows:
Mobile Client - Fixed Server Model (MC-FS Model): where the ‘client process’ requests for a
service on a different computer, the server that services the client’s request by performing
computations, managing data and all other shared resources on a fixed network and this will be
mange by the application located at the fixed network as shown in Figure 4.
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Figure.4 MC-FS Model
Mobile Client – Fixed Agent – Fixed Server Model (MC-FA-FS Model): This model the same
as client server model with augmented agent on the fixed network to his delegator. Actually such
model is proposed to overcome the connection’s variability and disconnection problem. See fig 2
Figure.5 MC-FA-FS Model
Mobile Client with Agent – Fixed Server with Agent Model (MCA-FSA Model): where the
agent at the client responsible for transaction and data management on behalf of mobile client.
See figure 3
Figure.6 MCA-FSA Model
A comparative overview of these models and other models that is not appropriate to be used in
our frameworks is given in [32].
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7. PERFORMANCE EVALUATION
The experiments were designed to study two dimensions: the first was concerning in the impact
of mobility and disconnection conditions on different execution strategies were defined by our
framework ; where as the second dimension is to compare and contrast the different execution
strategies using different computation models. The experiments were conducted first using the
first computation models (i.e. MC-FS) in order to study the execution strategies themselves, and
then we study the effect of those strategies on different computation models. In the former
experiments we study the response time, power consumption and throughput. Where the later
experiments we study the effect of the computation models namely MC-FS, MC-FA-FS and
MCA-FSA average number of restart per transaction using different execution strategies to find
out which computation models that fit with which execution strategy.
7.1. Simulation Mode1
The mobile system is abstracted as a queuing model. Its general structure is shown in Figure4.
The model consists of three servers labeled MH, MTM, and FH. The server MTM stands for the
mobile transaction manager related services. Normally, a mobile transaction request gets this
service first. Each mobile transaction issues a set of requests and each request represents one of
its subtransaction which could be a data request or a transaction request transaction based on the
execution strategy being applied. The server MH represents the services provided by a mobile
transaction host and the server FH the services provided by a fixed host where transaction
coordination takes place. If the subtarnsaction of a mobile transaction is scheduled as a Dreq-
transaction, when its basic subtransaction has finished its execution, the complementary
subtransaction is put into queue MQ1. If the network is connected, a Dreq complementary
subtransaction is submitted to a fixed host for processing and enters a queue FQ1; otherwise it has
to wait in MQ1 for network re-connection. If a Dreq complementary subtransaction is
successfully finish its execution. The mobile subtransaction is completed; otherwise, the
subtransaction fails. This process will be repeated for all sub transactions, when all
subtransactions are successfully completed, the entire mobile transaction is committed. For a
subtransaction that schedule as Treq, this process is identical; but with different notations of
Figure 4; that is if the network is connected, a T-req complementary subtransaction is submitted
to a mobile host for processing; otherwise it has to wait in MQ2 for network re-connection. The
CHS strategy can be viewed as a combination of the two basic strategies MHS and FHS. For the
MHS approach, each subtransaction in a mobile transaction goes through four processing steps:
data downloading, basic subtransaction processing, complementary subtransaction submission,
and complementary subtransaction processing. Thus, there are four simple services. Similarly, the
FHS approach has four simple services as well. The difference between the FHS model and MHS
model is that the data required by a mobile transaction is uploaded from the mobile host to a fixed
host. Besides, the first three simple services, i.e. data uploading, basic subtransaction processing
and complementary subtransaction submission, are implemented on a fixed host. Whereas
complementary subtransaction processing is performed by the mobile host that issues the
transaction. According to the BHS strategy, when a mobile host is disconnected a transaction is
treated as a Dreq transaction and has no data transmission. If the network is connected, the data
will be uploaded or downloaded based on current scheduling decision. Generally, the simulation
is conducted for the three strategies separately.
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Wireless link.
Wired link.
MTM Mobile transaction manager.
LTM Local transaction manager.
DM Data manager.
MH Mobile host
FH Fixed host.
Figure.7 The simulation model overview
If the policy is FHS, transaction requests are always scheduled as Treq transactions. If the
network is disconnected when a request arrives, this request must give up because its first
phase cannot be carried out. After the completion of the first phase, if the network is not
connected at this time, the complementary subtransaction cannot be submitted and must wait
in the queue. Unlike the FHS approach, the MHS strategy usually does not discard a transaction
request. Instead, the first phase of transaction processing is performed by using cached data even
if the network is disconnected. However, if the network is disconnected after this phase, the
request must be queued for later processing. For the BHS strategy, when the network is
disconnected, its work likes an MHS approach; otherwise, it functions as a mixture of the FHS
and MHS. Moreover, a complementary subtransaction may or may not be blocked. The network
connectivity directly impacts the performance of transaction processing. To reflect this, the time
spent on the completion of a Dreq transaction can be distinguished into four cases based on
the network connectivity during transaction execution. (1) A CC-type transaction is just like a
normal transaction where the network is in a fully connected condition. The other three types
of transactions indicate that at least one of two communication steps is broken (denoted by
the D). (2) CD-type transaction indicates that the network is connected at the time of the data
transmission and disconnected at the time of complementary subtransaction submission. (3) DC-
type transaction indicates that the network is disconnected at the time of the data transmission and
connected at the time of complementary subtransaction submission. (4) DD-type transaction
indicates that the network is disconnected at the time of the data transmission and the time of
complementary subtransaction submission. The performance of these four types of transaction
can be different. The functions to determine the execution and communication time is related to
the current state of the environment. In general the service type in the system can be classified
into two type communication oriented and processing oriented. For a communication oriented
service. The service time consists of a constant communication overhead and the data transport
time, which is determined by the size of data and the bandwidth at the time of data transfer. For a
processing oriented service, the service time is basically determined by the number of
accessed data items, the average number of operations on these items and the amount of time
spent in the fixed host which is based on different factors specified in section 6.2.
MQ1
MQ1
MQ1
MQ2
FQ1
MTM
MH
MH
MH
FT FT FT FT
I/O
LTMn
DM
I/O
LTM1
DM
FH
…
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7.2. System Parameters
The underlying mobile database system is composed of a number of databases distributed among
fixed and mobile hosts. Transaction-generators are responsible for creation of transactions to be
executed in the system. Parameters controlling the generation of transactions include the
workload (the number of concurrent transaction per unit of time allowed in the system); the
average, minimum, and maximum number of subtransactions in each mobile transaction; the
average, minimum, and maximum number of database operations in a subtransaction; the
probability of a write operation. The global workload consists of randomly generated local and
mobile transactions spanning over a random number of sites. At each local site, there are a
number of local transactions. The local system does not differentiate between the two types (local
transaction and mobile subtransaction). Transactions enter the execution phase are subsequently
scheduled by acquiring the necessary lock on their data items. If the lock is granted, the
operations proceeds through the CPU and I/O queue, and for a mobile subtransaction an abort or
commit signal is communicated back to the MTM and the subtransaction terminates. The local
system may abort a local transaction or a mobile subtransaction at any time. If a mobile
subtransaction is aborted locally, it’s communicated to the MTM and the mobile transaction is
aborted at all sites and restarted. The communication between the mobile host and the MTM can
occur in both direction using either an uplink channel for uploading data or downlink channel for
downloading. The communication overhead for uplink and downlink channels is 30 and 10
respectively. When the disconnection occurs, the mobile unit is disconnected for 20-30 second. In
order to effectively evaluate the different execution strategies, several parameter are varied for
different simulation runs. Most of these parameters are given in Tables 1, 2 and 3 along with their
default values.
Table 1. Communication Parameters
Communication Parameters Default Values
Arrival of mobile transaction 5
Arrival of fixed transaction 5
Mobility timer 5,10,15,..., 50
Disconnection Threshold 1000 , 500, 100
UplinkBW 10-1500
DlinkBW 10-3000
Disconnection Period 20 – 30 Second
Service time for each communicated message using Uplink Channel 30
Service time for each communicated message using Downlink 10
Table 2. Fixed Host Parameter
Fixed Host Parameter Default Values
Number of LTM 10
Number of local transactions Up to 500
Number of operation in each local transaction 6- 12
Probability of write operation for local transaction 0.3- 0.5
Lock time for each operation 10
Concurrency protocol 2 Phase Locking
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Table 3. Mobile Host Parameters
Mobile Host Parameters Default Values
Number of mobile units 500
Number of mobile sub transactions 1-10
Number of operations in each sub- transaction 6- 12
Probability of write operation 0.3 – 0.5
Probability of cash hit 0.2 – 0.8
Execution cost at the mobile host 2-5
Mobility value of mobile host number of visited MTM 5 – 50
7.3. Experiment Results and Discussion
The experiments are designed to study the impact of mobility ratio under different disconnection
conditions on the performance measures to compare and contrast the different execution
strategies. Figures 8 -13 show the impact of changing network conditions on the response time
for both mobile and fixed transaction under different execution strategies. In each experiment,
1000 transactions are generated and 60% of these transactions are mobile. The mobility timer is
varies from 5 to 50 seconds.
Figure 8: Response time for mobile transaction Figure 9: Response time for fixed transaction
Figure 10: Response time for mobile transaction Figure 11: Response time for fixed
transaction
Figure 8 shows the results when a mobile host has low disconnection (disconnection threshold is
BW<=100). It can be seen that among the three approaches, the FHS outperform the other
strategies, whereas the MHS is the worst. This is because a mobile subtransaction that schedules
as a data request transaction needs more data transmission than if schedule as a transaction
request. Moreover, a data request transaction takes a longer time for global commitment. This can
14. International Journal of Database Management Systems ( IJDMS ) Vol.6, No.2, April 2014
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be reflected in the response time for the fixed transaction as we can see in Figure 9. The CHS
strategy is closer to FHS than to MHS which means that most of mobile subtransactions are
scheduled as transaction requests. Even though the network is highly connected, the performance
of the CHS may not outperform the FHS strategy. This is because the network connectivity is not
the only factor which affecting the decision made by the CHS strategy to determine where the
mobile subtransaction execution is take place, the size of data to be transmitted and the cash
status also affecting the decision made by the CHS. So, if the cache status indicates that cached
data for a transaction is available, the transaction may schedule as a data request transaction, even
though the network is fully connected. Therefore, unlike the FHS strategy, the sub transactions of
the mobile transaction may scheduled in a mixed matter based on the current state of the
environment at that time. Figure10 and11 shows the results when a mobile host has medium
disconnection (disconnection threshold is BW<=500) for both mobile and fixed transaction,
respectively. It can be seen that the response time for all strategies are negatively affected by
increasing the disconnection threshold. However, because of increasing disconnection
probability, the performance of the FHS strategy becomes less than the other two strategies and
CHS has the best performance. The reason is that when the network disconnection probability
increases, the number of mobile subtarnsaction which schedule as data requests increase. On the
other hand, the mobile subtransaction at connection time was scheduled as a transaction request,
so this environment gives the CHS strategy more chance to exploit the information at the current
environment state which makes it better than FHS at the disconnection time and also better than
MHS at connection time. In Figure 11 the difference between the FHS and other strategies is
more obvious than Figure 9. Since the disconnection probability is increases, The FHS strategy
has more chance to block the basic transaction which comprises the first phase of any mobile
subtransaction execution. This will decrease the blocking over head on the fixed transaction at the
fixed host. On the other hand, in MHS and CHS strategies, a cached data can be used to execute
the basic transaction. So, there is no need to block a mobile subtransaction if the cash status of
the required data items is valid. As a consequence, the response time of mobile transactions
decreases substantially when compared to the FHS approach. The advantages get by the mobile
transaction under MHS and CHS in term of decreasing the response time will be negatively affect
the fixed transaction as it have to wait for the basic transactions of the mobile subtransaction until
finish its execution at the mobile host which is take a longer time than if the execution is take
place at the fixed host. This can be seen in the Figure 12 and 13 which show the response time for
both fixed and mobile transaction when there is a high disconnection, respectively.
Figure 12: Response time for mobile transaction Figure 13: Response time for fixed transaction
The battery of mobile hosts considered to be one of a scarce resource in the mobile computing
environment [14], an experiment is conducted to show the difference between three strategies in
term of power consumption. Figures 14-16 show the simulation results for different mobility
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value with different disconnection thresholds. Since the whole mobile transaction take place at
the fixed host under FHS strategy, only the communication overhead can affect the power
consumption of the mobile host. This justifies the significant difference between FHS and other
strategies Figure 14. On the other hand, the MHS has the worst effect on power consumption
because all mobile transaction processing take place at the mobile host. The difference between
the power consumption for the CHS and MHS strategies decrease as disconnection increases
since there is more chance for mobile subtransaction to schedule as a data request transaction.
Figure 14 shows that when the network is strongly connected.
Figure 14: Power consumption Figure 15: Power consumption
Figure 16: Power consumption
The MHS strategy takes more processing time on a mobile host than the CHS strategy. This is
because, with the CHS, the number of mobile sub transactions which are scheduled as transaction
requests increase so that the time spent on the mobile host is reduced. As the network
disconnection increase the CHS strategy still has a better performance in reducing power
consumption at the mobile host than MHS. However, as the network disconnection probability
increase further, The Power consumption under CHS strategy approach the power consumption of
the MHS strategy as we can see in Figure 16.
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Figure 17: Throughput for mobile transactions Figure 18: Throughput for fixed transactions
Figures 17-22 show the experimental results for system throughputs in terms of the number of
completed transactions during a time interval using CHS strategies. The first experiment show the
result under different workload assumptions where the mobility and the disconnected threshold
are set to 20 and 500 respectively. The purpose of this experiment is to show how the MCA-FSA
model gives better performance than other Computation models as workload increases at the
average network connection for mobile transactions. As we can see in Figure 17 the MCA-FSA
model consistently demonstrates better performance than MC-FA-FS and MC-FS computation
models for a mobile transaction where Figure 18 show how the MCA-FSA model are close to the
MC-FS computation model in term of fixed transaction throughput.
Figure 19: Throughput for mobile transaction Figure 20: Throughput for fixed transactions
Figure 19 and 20 illustrates that with low disconnection (disconnection threshold =100); the MC-
FS model has the highest throughput for both types of transactions where there is an improvement
in fixed transaction throughput over the case of medium disconnection. While the MC-FA-FS the
lowest and the MCA-FSA approach is in between the two. This result is consistent with the result
shown in Figure 8 and 9 as an approach with a lower throughput can have a longer response time.
However, Figure 21 shows degradation under all computation models with high disconnection
probability for mobile transactions. The MCA-FSA can produce better throughput over the other
two approaches because the basic transaction under the MC-FS model is unable to get through
during network disconnection. At the same time, despite that the MC-FA-FS can carry on
transaction processing with cached data it is ignoring the time interval during the connection
period of the network. For the throughput of the fixed transaction, MC-FS model still have the
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35
superior over the other two computation models and the MCA-FSA become closer to the MC-
FA-FS model than to MC-FS as we can see in the Figure 22.
Figure 21: Throughput for mobile transactions Figure 22: Throughput for fixed transactions
Additional experiments were added Figure 23-25 that show the difference between different
computation models over different execution strategies in this experiments, 50% of transactions
were generated are mobile. The mobility timer is varies from 5 to 50 seconds and the workload is
set to its default value with medium disconnection probability (disconnection threshold <=500);
the result show that best gain of all is when we used the combined execution strategies CHS with
MCA-FSA as the underling computation model.
Figure 23: Different execution strategies under MCA-FSA model
Figure 24: Different execution strategies under MC-FS model
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Figure 25: Different execution strategies under MC-FA-FS model
8. CONCLUSION
Mobility brings in new dimension to the existing solutions to the problems in distributed
databases. We have reviewed some of the problems and existing solutions in that direction. We
have highlighted the merits and demerits of existing solutions. We have found from the previous
papers that, no comparative performance evaluation of models is presented. We observe that there
is a need to investigate the properties of mobility, which can impact most the transaction
processing. Also, there is a need to evaluate various transactions processing where a mixed fixed
and mobile transactions are coexist in the system. In this paper we have introduce a frame work to
investigate three transaction execution strategies based on the general assumption that the
information of environment current state are available. To do so, we have built a simulator to
imitate the mobile data base system with mixed transaction running on the system. To summarize,
the simulation experiments performed in this paper investigate the performance of three
transaction processing policies under the assumption that network disconnection occurs. The
experiments are conducted from several perspectives by adjusting model parameters, such as,
average inter-event time of bandwidth change and disconnection ratio. The simulation results
show that if there is little or no network disconnection. The FHS has the shortest response time
and the highest system throughput. This is not surprising because the system operates at or near
the traditional fixed network environment. However, as network connectivity deteriorates, the
MHS produces better system throughput and response time than the FHS. In general, the CHS
approach produces better performance in terms of overall response time, elapsed processing time
of a mobile host and total number of transactions completed by the system. Over all, the result
show that best gain of all is when we used the combined execution strategies CHS with MCA-
FSA as the underling computation model.
ACKNOWLEDGEMENTS
This research is funded by the Deanship of Research and Graduate Studies in Zarqa University
/Jordan
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[24] R. Hirsch, A. Coratella, M. Felder and E. Rodríguez: A Framework for Analyzing Mobile Transaction
Models, Journal of Database Management, 12(3), 2001, pp 36-47.
[25] T. Kaneda, M. Shiraishi, T. Enokido and M. Takizawa: Mobile Agent Model for Transaction
Processing on Distributed Objects, International Conference on Advanced Information Networking
and Applications (AINA), 2004, pp506-511.
[26] atricia Serrano-Alvarado, Claudia Roncancio, Michel Adiba, “A Survey of Mobile Transactions”,
Distributed and Parallel databases, 16,193-230, 2004, Kluwer Academic Publishers.
[27] V. Kumar, N. Prabhu, M. H. Dunham and A. Y. Seydim: TCOT-A Timeout- Based Mobile
Transaction Commitment Protocol, IEEE Transactions on Computers, 51(10), 2002, pp 1212-1218.
[28] D. L. R. Salman Abdul Moiz, "A Real Time Optimistic Strategy to achieve Concurrency control in
Mobile Environments using ondemand multicasting," International Journal of Wireless & Mobile
Networks (IJWMN), vol. 2, pp. 172-185, 2010.
[29] S. Madria, M. Baseer, V. Kumar, and S. Bhowmick, 2007"A transaction model and multiversion
concurrency control for mobile database systems,” Parallel Databases, vol. 22, pp. 165-196,.
[30] Ahmad al-Qerem, "Framework for Transaction Execution Strategies in Mobile Data Base Systems,"
International Journal of Electronics and Electrical Engineering, Vol. 1, No. 1, pp. 15-18, March 2013.
doi: 10.12720/ijeee.1.1.15-18.
[31] Venkatraman, S, “Mobile Computing Models - Are they Meeting the Mobile Computing
Challenges?” Association for Computing Machinery New Zealand Bulletin, 1 (1) (ISSN 1176-9998),
2005.
AUTHOR
Ahmad Alqerem obtaining a BSc in 1997 from JUST University and a Masters in
computer science from Jordan University in 2002. PhD in mobile computing at
Loughborough University, UK in 2008. He is interested in concurrency control for
mobile computing environments, particularly transaction processing. He has
published several papers in various areas of computer science. After that he was
appointed a head of internet technology Depts. Zarka University