In public safety scenarios, communication between responders is crucial to ensure better cooperation during rescue missions. Several Mission critical services have been proposed by 3GPP, enabling the exchange of data, voice, and multimedia content over the latest generation of cellular networks. Despite the great popularity of cellular technologies, there are limitations when users exchange large amounts of data traffic at the edge of the antenna. By taking advantage of the proximity between users, deploying Device-to-Device (D2D) communication should offer better bandwidth, lower delays, and optimized device energy consumption. To overcome the range limitations of Direct D2D communication, a multi-hop cooperative relay based on CQI (Channel Quality Indicator) can route the message to the final destination. Two communication modes are thus proposed: (1) the D2D Loosely Coupled mode, which relies exclusively on user-type relays, and (2) the Hybrid mode, which allows the cellular antenna to be used as a relay when routing packets. This paper proposes modeling and evaluation of these solutions in the context of rescue operations, using an extension of the Simu5G library under the OMNeT++ simulator. Several configurations, including different application bitrates, showcase the coverage capabilities and related end-to-end delays when using a multi-relays solution compared to Direct D2D communication. The D2D Loosely coupled and Hybrid modes are evaluated and compared to the Infrastructure mode, particularly when traffic moves to the edge of the cell. Hybrid mode performance has been highlighted through a series of mobility scenarios.

The fifth and beyond generations of communications (B5G/6G) aim to support massive connected objects and mission-critical applications. In the context of disaster management, the vehicles coordinating rescue operations in each area can also serve as local communication relays for the other participants. The evaluation of such applications at a city scale requires accurate modelling of both urban mobility and vehicular communications. Most works propose either analytical models providing a big picture of the performance expected in large-scale deployments, or real-world testing at a lower scale showing performance for concrete but limited scenarios. This paper proposes a simulation approach to the evaluation of 5G relay-empowered communications, which uses an event-based urban traffic modelling in order to accelerate large-scale simulations. It also uses propagation models designed from real-world measurements performed on mobile operators’ 5G infrastructure, which allows to envision the 5G communication performance that could be expected for applications such as cooperative localization and extended perception between the participating vehicles. The evaluations over a relay-empowered 5G network including one base station (gNB), 180 relays, and up to 350 vehicles in an urban city show that the relays improve downlink communications speed and end-to-end delay, while the gNB provides higher speeds in uplink communications overall. These evaluation results draw the performance expected from existing 5G deployments, and offer insight for communication management policy regarding the applications involved in rescue operations.

Among the strategies of the fifth and beyond generations of communications (B5G/6G) to manage massive connected objects and their increased experience requirements, using relays is gaining much interest. Particularly, the infrastructure supporting applications such as Rescue Operations can beneficially use relay-empowered approaches for efficient disaster management in a city. Several works propose analytical models providing a big picture of the performance expected in large scale deployments. Conversely, real-world testings at a lower scale show performance for more concrete but very limited scenarios. This paper proposes a simulation based approach to evaluation of such applications. It uses an event-based urban traffic modelling that accelerates large-scale simulation, even at the level of a city. It also uses propagation models designed from real-world measurements performed on mobile operator 5G infrastructure to obtain performance results close to reality. The evaluations over a relay-empowered 5G network including one base station, 180 relays and up to 350 vehicles in an urban city, show the gain on metrics such as end-to-end delay and communication speed when using relays.

Smart environments and technology used for elder care, increases independent living time and cuts long-term care costs. A key requirement for these systems consists in detecting and informing about abnormal behavior in users'routines. In this paper, our objective is to automatically observe the elderly behavior over time and detect anomalies that may occur on the long term. Therefore, we propose a learning method to formalize a normal behavior pattern for each elderly people related to his Activities of Daily Living (ADL). We also adopt a temporal similarity score between activities that allows to detect behavior changes over time. In change behavior period we focus on each activity to detect anomalies. A use case with real datasets are promising.

A sensor-rich environment can be exploited for elder healthcare applications. In this work, our objective was to conduct a continuous and long-term analysis of elderly's behavior for detecting changes. We indeed did not study snapshots of the behavior but, rather, analyzed the overall behavior evolution over long periods of time in order to detect anomalies. Therefore, we proposed a learning method and formalize a normal behavior pattern for elderly people related to her/his Activities of Daily Living (ADL). We also defined a temporal similarity score between activities that allows detecting behavior changes over time. During the periods of time when behavior changes occurred, we then focused on each activity to identify anomalies. Finally, when a behavior change occurred, it was also necessary to help caregivers and/or family members understand the possible pathology detected in order for them to react accordingly. Therefore, the framework presented in this article includes a fuzzy logic-based decision support system that provides information about the suspected disease and its severity.

Development of mobile applications has previously encountered, and still encounters, challenges related to the specificity of the mobile world. The usual rules of software engineering tend not to respond to certain mobile development issues. In this paper, we identify and address the challenges of mobile development. We propose a quality model and analysis adapted from ISO9126. Based on this model, we have developed a tool to analyze an application’s source code and measure the achievement of quality criteria. We describe all the notions of quality and the check points in the mobile application’s source code. This work was carried out in partnership with a mobile application development company, COMPANY, to test our tool on real-world applications. We also discuss the results obtained and feedback from COMPANY developers on our tool

During last years development frameworks have emerged to make easier the development and maintenance of cross-platform mobile applications. Xamarin framework is one of them: it takes as input an app written in C# and produces native code for Android, iOS and Windows Mobile platforms. When using Xamarin, developers can meet errors, identified with codes, thrown by the framework.Unfortunately, the Xamarin official documentation does not provide a complete description, solution or workaround for all those codes.In this paper, we analyze two sites of questions and answers related to Xamarin for finding questions that mention those error codes. We found in both sites that there are questions written by developers asking about Xamarin errors, and the majority of them have at least one answer. Our intuition is this discovered information could be useful for giving support to Xamarin developers.

A cross-platform mobile application is an application that runs on multiple mobile platforms (Android or iOS platforms). One strategy for developing this kind of mobile applications involves to develop, using platform-related toolkits, a native application for each chosen platform. Several frameworks have been proposed to simplify the development of cross-platform mobile applications and, therefore, to reduce development and maintenance costs. Between them, the cross-compiler mobile development frameworks transform the application's code written in intermediate (aka non-native) language to native code for each platform. However, to our best knowledge, there is no much research about the advantages and disadvantages of the use of cross-compiler frameworks during the development and maintenance phases of mobile applications. This paper aims at contributing with one of the first bricks in that research direction. We study what mobile developers that use cross-compiler frameworks ask about when they develop and maintain cross-platform mobile applications. In particular, we focus on one framework: Xamarin from Microsoft. For that, we first created two datasets of questions and answers (QA) related to the development of mobile applications using Xamarin by mining two QA sites: Xamarin Forum and Stack Overflow. We analyzed and compared the number of questions, views and accepted. Then, we applied LDA on Xamarin-related questions to discover the main topics asked by developers that use Xamarin. Finally, we compared the discovered topics with those topics about mobile development. Our findings show that Xamarin Forum has a larger number of questions than Stack Overflow, however, the latter has more answers per question. Moreover, both sites share most of the main topics, which mainly discuss about user interface (UI), formatting, design and navigation.

—This paper discusses quality markers for a mobile application, both during conception and development, to propose the most suitable way to validate them automatically. We focus on native and cross-platform applications, as well as component based development. To achieve this, we rely both on research papers of the domain, and on our partnership with the Keyneosoft company. An industrial expertise is useful to identify real prob- lems encountered with quality processing for mobile applications.

During last ten years, the number of smartphones and mobile applications has been constantly growing. Android, iOS and Windows Mobile are three mobile platforms that cover almost all smartphones in the world in 2017. Developing a mobile app involves first to choose the platforms the app will run, and then to develop specific solutions (i.e., native apps) for each chosen platform using platform-related toolkits such as Android SDK. A cross-platform mobile application is an app that runs on two or more mobile platforms. Several frameworks have been proposed to simplify the development of cross-platform mobile applications and to reduce development and maintenance costs. They are called cross-platform mobile app development frameworks. However, to our knowledge, the life-cycle and the quality of cross-platforms mobile applications built using those frameworks have not been studied in depth. Our main goal is to first study the processes of development and maintenance of mobile applications built using cross-platform mobile app development frameworks, focusing particularly on the bug-fixing activity. Then, we aim at defining tools for automated repairing bugs from cross-platform mobile applications.

Android and iSO are the two mobile platforms present in almost all smartphones build during last years. Developing an application that targets both platforms is a challenge. A traditional way is to build two different apps, one in Java for Android, the other in Objective-C for iOS. Xamarin is a framework for developing Android and iOS apps which allows developers to share most of the application code across multiple implementations of the app, each for a specific platform. In this paper, we present XamForumDB, a database that stores discussions, questions and answers extracted from the Xamarin forum. We envision research community could use it for studying, for instance, the problematic of developing such kind of applications.

The optimised link state routing OLSR protocol is one of the most promising for mobile ad hoc networks MANETs. Despite numerous proposals for quality of service in MANET, there is a lack of OLSR implementations that efficiently support applications with stringent QoS constraints like VoIP or videoconference. In this paper, we present a QoS-OLSR implementation based on a multiple-metric approach. We first describe how QoS metrics values are estimated and disseminated. Then we show how the multipoint relays MPR can be selected using the QoS metrics as criteria, while keeping low the number of MPR in order to ensure flooding optimisation. The underlying problem is formally presented as a multicriteria problem. Finally, a heuristic is proposed in order to find quickly a satisfying solution to this latter. The evaluations carried out using OPNET show that, despite the additional traffic introduced by the dissemination of QoS information, QoS-OLSR achieves better performance than native OLSR for best-effort applications as well as for applications that are subject to QoS constraints.

There is a multitude of mobile OS: iOS android, Windows Phone 8 and each OS provides its own standards and tools. This heterogeneity in the mobile domain forces developers to implement an application for e ach mobile platform. To achieve that, developers need t o master several languages (Java, Objective-C…). They also need to have several devices at their disposal (PC, Mac, many smartphones …). Then, after applications distributions, developers have to main tain several source codes. In this study, we tackle this problematic. Our goal is to soften the differences between each OS in order to simplify the development of cross-platform third-party applications. To achieve that, we have defined a framework called COMMON (Component Oriented programming for Mobile Multi OsiNtegration). This framework allows the integration of cross-platform components in any app lication (iOS android). To run our components on an y OS, we provide an implementation for each platform. However, to make their integrations easier, we als o provide a common public interface of each component, which is platform-independent. Besides, we provid e a common language, also platform-independent, allowing the integration and use of any component in any native application (iOS android). This language is based on annotations. Finally, we have implemented a cross-compiler, which translates the source code wr itten with our language to native source code: Obje ctiveC for iOS, Java for Android,… In this study, we hav e shown that our solution offers performance and memory consumption closed to native applications. Finally, with COMMON, mobile developers implement less lines of source code than with a native applic ation. In your test application, we have saved 30%.

The work presented in this paper focuses on the use of the CATS framework (a framework dedicated to the adaptation and the deployment of context aware services in the transportation context) on applications designed to assist the user in transportation activities (e.g., driving assistant, visiting a city, finding a parking place etc.). We present a solution to deploy and use these services when users do not have a connection to WAN by using asynchronous solutions based on smart cities infrastructures. A prototype has been developed and evaluated at the end of this paper.

Smartphones provide a set of native functionalities and another set of functionalities available through third-party applications. The emergence of more and more actors, without standards to provide their devices or OS, stops the cross-platform development. Indeed, a developer would have to learn many programmatic languages and create many user interfaces for many devices. To resolve this problem, several solutions often consist in the creation of a com- mon SDK to only write the application once. Then, the application code is translated in native code for each target platform. In this paper, we propose a solution based on a component model. A set of configurable components is implemented for the targeted platforms. A component will have a common interface independent from the host OS. Finally, a new language will offer developers a single instruction call to any component through its interface. This instruction is common on any platforms to simplify the implementation of a cross-platform application.

By exchanging events in a vehicular ad hoc network VANET, drivers can receive interesting information while driving. For example, they can be informed of available parking spaces in their vicinity. A suitable protocol is needed to disseminate the events efficiently within the area where they are relevant. Moreover, in such a competitive context where each vehicle may be interested in a resource, it is crucial not to communicate that resource to each driver in the vicinity. Otherwise, those drivers would waste time trying to reach a parking space and only one of them would be fulfilled, which would lead to a poor satisfaction in the system. To solve this problem, we detail in this paper a reservation protocol that efficiently allocates parking spaces in vehicular ad hoc networks and avoids the competition among the vehicles. We have integrated our protocol within VESPA, a system that we have designed for vehicles to share information in VANETs. An experimental evaluation is provided, which proves the usefulness and benefits of our reservation protocol in both parking lots and urban scenarios. Besides, we present an in-depth study of the state of the art on this topic, that shows the interest and the originality of our approach.

Personal and mobile computing systems represents nowadays one of the biggest market segment and fastest adopted products. The importance of saving power for these handheld devices is critical. The benefits are increasing battery life and system reliability. In these systems, power not only goes to the processing elements but also to Input/Output (IO) subsystem such communication peripherals and LCD display. In this paper, we propose a new tool that offers exploiting user's information such as its position, needs and history to reduce energy consumption.

This article describes an easy, efficient way to manage context-aware applications with the help of metadata. We rely on CATS, our proposition for an application framework embedded on mobile devices. It is designed to host applications conforming to the SOA principles for achieving a flexible and dynamic architecture. Our framework provides non-functional capabilities for context management and for the adaptations required at context changes. In this article we focus on the use of iPOJO handlers and the advantages they bring to the OSGi technology.