A comparative analysis of adaptive middleware architectures based on computational reflection and aspect oriented programming to support mobile computing applications

Mobile computing applications are required to operate in environments in which the availability for resources and services may change significantly during system operation. As a result, mobile computing applications need to be capable of adapting to these changes to offer the best possible level of service to their users. However, traditional middleware is limited in its capability of adapting to environment changes and different users requirements. Computational Reflection and Aspect Oriented Programming paradigms have been used in the design and implementation of adaptive middleware architectures. In this paper, we propose two adaptive middleware architectures, one based on reflection and other based on aspects, which can be used to develop adaptive mobile applications. The reflection based architecture is compared to an aspect oriented based architecture from a quantitative perspective. The results suggest that middleware based on Aspect Oriented Programming can be used to build mobile adaptive applications that require less processor running time and more memory space than Computational Reflection while producing code that is easier to comprehend and modify.8th IFIP/IEEE International conference on Mobile and Wireless CommunicationRed de Universidades con Carreras en Informática (RedUNCI

Data Synchronization in a Network-Volatile Mobile Ecosystem

Today, it is a major issue for mobile applications to maintain a replica state of the server on mobile devices. This creates the need to keep data on both the server and the mobile. In such cases, when the data changes on the server, the new state of the data has to be updated on the mobile in order to maintain a consistent view of the data flow. However, mobile devices communicate over wireless mediums (.e.g., Bluetooth, Wi-Fi, 3.5G/4G, etc.) which can experience intermittent connectivity. The volatility of the network is also influenced by low-bandwidth. The direct effects of these issues are high latency and inconsistency issues between the data on the mobile clients and the remote servers. In this work, I present a detail review on the topic of data synchronization in mobile networks. Then, a generic architecture called MobiQ is proposed which can keep working in an offline mode to record local modifications and can synchronize with the remote servers when connectivity is restored. This is achieved through the proposal of an efficient synchronization protocol which combines different synchronization and replication strategies. Moreover, the MobiQ framework provides a secured environment to work with data. The implemented architecture is designed and tested in mobile questionnaire system and the result is encouraging

User-activity aware strategies for mobile information access

Information access suffers tremendously in wireless networks because of the low correlation between content transferred across low-bandwidth wireless links and actual data used to serve user requests. As a result, conventional content access mechanisms face such problems as unnecessary bandwidth consumption and large response times, and users experience significant performance degradation. In this dissertation, we analyze the cause of those problems and find that the major reason for inefficient information access in wireless networks is the absence of any user-activity awareness in current mechanisms. To solve these problems, we propose three user-activity aware strategies for mobile information access. Through simulations and implementations, we show that our strategies can outperform conventional information access schemes in terms of bandwidth consumption and user-perceived response times.Ph.D.Committee Chair: Raghupathy Sivakumar; Committee Member: Chuanyi Ji; Committee Member: George Riley; Committee Member: Magnus Egerstedt; Committee Member: Umakishore Ramachandra

Mobile Databases: a Selection of Open Issues and Research Directions

International audienceThis paper reports on the main results of a specific action on mobile databases conducted by CNRS in France from October 2001 to December 2002. The objective of this action was to review the state of progress in mobile databases and identify major research directions for the French database community. Rather than provide a survey of all important issues in mobile databases, this paper gives an outline of the directions in which the action participants are now engaged, namely: copy synchronization in disconnected computing, mobile transactions, database embedded in ultra-light devices, data confidentiality, P2P dissemination models and middleware adaptability

Data Replication for Improving Data Accessibility in Ad Hoc Networks

In ad hoc networks, due to frequent network partition, data accessibility is lower than that in conventional fixed networks. In this paper, we solve this problem by replicating data items on mobile hosts. First, we propose three replica allocation methods assuming that each data item is not updated. In these three methods, we take into account the access frequency from mobile hosts to each data item and the status of the network connection. Then, we extend the proposed methods by considering aperiodic updates and integrating user profiles consisting of mobile users\u27\u27 schedules, access behavior, and read/write patterns. We also show the results of simulation experiments regarding the performance evaluation of our proposed method

Framework for supporting JavaScript-Based Mobile Agents

The evolution of technology in interconnection solutions, such as networks or the Internet, and the emergence both of wireless sensors networks and distributed systems allowed many communication architectures to appear, being the Client-server architecture the most common. Here, we present a dissertation work about the mobile agents computing paradigm. A middleware and a mobile agent framework have been developed using the JavaScript language that allows the development, execution and the ability to move JavaScript mobile agents through the local network and Internet using Node.js for desktop operating systems and React Native for mobile operating systems, such as Android and iOS. This initiative arose as a way of dealing with problems raised by the considerable amount of existing Java based mobile agents platforms, which force the installation of the Java Virtual Machine on the devices, making complicated its execution in operating systems like macOS, iOS and others operating systems not compatible with Java

FEW phone file system

Trabalho apresentado no âmbito do Mestrado em Engenharia Informática, como requisito parcial para obtenção do grau de Mestre em Engenharia InformáticaThe evolution of mobile phones has made these devices more than just simple mobile communication devices. Current mobile phones include such features as built-in digital cameras, the ability to play and record multimedia contents and also the possibility of playing games. Most of these devices have support for Java developed applications, as well as multiple wireless technologies (e.g. GSM/GPRS, UMTS, Bluetooth, and Wi-Fi). All these features have been made possible due to technological evolution that led to the improvement of computational power, storage capacity, and communication capabilities of these devices. This thesis presents a distributed data management system, based on optimistic replication,named FEW Phone File System. This system takes advantage of the storage capacity and wireless communication capabilities of current mobile phones, by allowing users to carry their personal data “in” their mobile phones, and to access it in any workstation, as if they were files in the local file system. The FEW Phone File System is based on a hybrid architecture that merges the client/server model with peer-to-peer replication, that relies on periodic reconciliation to maintain consistency between replicas. The system’s server side runs on the mobile phone, and the client on a workstation. The communication between the client and the server can be supported by one of multiple network technologies, allowing the FEW Phone File System to dynamically adapt to the available network connectivity. The presented system addresses the mobile phone’s storage and power limitations by allowing multimedia contents to be adapted to the device’s specifications, thus reducing the volume of data transferred to the mobile phone, allowing for more user’s data to be stored. The FEW Phone File System also integrates mechanisms that maintain information about the existence of other copies of the stored files (e.g. WWW), avoiding the transfer of those files from the mobile device whenever accessing those copies is advantageous. Due to the increasing number of on-line storage resources (e.g. CVS/SVN, Picasa), this approach allows for those resources to be used by the FEW Phone File System to obtain the stored copies of the user’s files

Small cell cloud proof of concept implementation and monitoring schemes analysis

Cloud Computing has grown exponentially in popularity in the last few years, becoming a key technology for both personal and enterprise applications due to the numerous benefits it offers. On the other hand, Small Cell technology is considered by many to be the solution to the challenges that are expected to arise caused by the continuously increasing number of interconnected mobile devices. This project presents a basic design and a proof of concept implementation of a Small Cell Cloud, a current research field on mobile communications that aims to leverage the capabilities offered by the parallel and distributed computation of Cloud Computing to enhance Small Cells functionality. The purpose of the described Small Cell Cloud is to allow application offloading of mobile devices to Small Cells, allowing the execution of more resource demanding applications at the same time energy consumption is reduced in those devices. Furthermore, a detailed analysis on different Small Cell monitoring schemes is carried out, comparing the achieved performance with each of them in terms of data reliability and generated network traffic. Finally, based on the proof of concept implementation and a series of stress performance test, conclusions on the viability of the proposed Small Cell Cloud design and the most appropriate monitoring scheme are presented. Guidelines for future research work are also provided, considering the work developed in this project as a first step towards a new mobile technology.Ingeniería de Telecomunicació