A novel data replication and management protocol for mobile computing systems

Mobile computing has enabled users to seamlessly access databases even when they are on the move. Mobile computing environments require data management approaches that are able to provide complete and highly available access to shared data at any time from any where. In this paper, we propose a novel replicated data protocol for achieving such goal. The proposed scheme replicates data synchronously over stationary sites based on three dimensional grid structure while objects in mobile sites are asynchronously replicated based on commonly visited sites for each user. This combination allows the proposed protocol to operate with less than full connectivity, to easily adapt to changes in group membership and not require all sites to agree to update data objects at any given time, thus giving the technique flexibility in mobile environments. The proposed replication technique is compared with a baseline replication technique and shown to exhibit high availability, fault tolerance and minimal access times of the data and services, which are very important in an environment with low-quality communication links.

Supporting disconnected operations in mobile computing

Mobile computing has enabled users to seamlessly access databases even when they are on the move. However, in the absence of readily available high-quality communication, users are often forced to operate disconnected from the network. As a result, software applications have to be redesigned to take advantage of this environment while accommodating the new challenges posed by mobility. In particular, there is a need for replication and synchronization services in order to guarantee availability of data and functionality, (including updates) in disconnected mode. To this end we propose a scalable and highly available data replication and management service. The proposed replication technique is compared with a baseline replication technique and shown to exhibit high availability, fault tolerance and minimal access times of the data and services, which are very important in an environment with low-quality communication links.

A new approach for efficiently achieving high availability in mobile computing

Recent advances m hardware technologies such as portable
computers and wireless communication networks have led to the emergence of mobile computing systems. Thus, availability and accessibility of the data and services become important issues of mobile computing systems. In this paper, we present a data replication and management scheme tailored for such environments In the proposed scheme data is replicated synchronously over stationary sites while for the mobile network, data is replicated asynchronously based on commonly visited sites for each user. The proposed scheme is compared with other techniques and is shown to require less communication cost for an operation as well as provide higher degree of data availability.

Contextual influences on user satisfaction with mobile computing : findings from two healthcare organizations

Mobile information technologies (IT) are transforming individual work practices and organizations. These devices are extending not only the boundaries of the ‘office’ in space and time, but also the social context within which use occurs. In this paper, we investigate how extra-organizational influences can impact user satisfaction with mobile systems. The findings from our longitudinal study highlight the interrelatedness of different use contexts and their importance in perceptions of user satisfaction. The data indicate that varying social contexts of individual use (individual as employee, as professional, as private user, and as member of society) result in different social influences that affect the individual’s perceptions of user satisfaction with the mobile technology. While existing theories explain user satisfaction with IT within the organizational context, our findings suggest that future studies of mobile IT in organizations should accommodate such extra-organizational contextual influences.

Security framework for mobile agents-based applications

Mobile agents have been proposed for key applications such as forensics analysis, intrusion detection, e-commerce, and resource management. Yet, they are vulnerable to various security threats by malicious hosts or intruders. Conversely, genuine platforms may run malicious agents. It is essential to establish a truly secure framework for mobile agents to gain trust of clients in the system. Failure to accomplish a trustworthy secured framework for Mobile Agent System (MAS) will limit their deployment into the key applications. This chapter presents a comprehensive taxonomy of various security threats to Mobile Agent System and the existing implemented security mechanisms. Different mechanisms are discussed, and the related security deficiencies are highlighted. The various security properties of the agent and the agent platform are described. The chapter also introduces the properties, advantages, and roles of agents in various applications. It describes the infrastructure of the system and discusses several mobile agent frameworks and the accomplished security level.

Comparative mobile platforms security solutions

 Mobile platform security solution has become especially important for mobile computing paradigms, due to the fact that increasing amounts of private and sensitive information are being stored on the smartphones' on-device memory or MicroSD/SD cards. This paper aims to consider a comparative approach to the security aspects of the current smartphone systems, including: iOS, Android, BlackBerry (QNX), and Windows Phone.

A shadow-like task migration model based on context semantics for mobile and pervasive environments

Pervasive computing is a user-centric mobile computing paradigm, in which tasks should be migrated over different platforms in a shadow-like way when users move around. In this paper, we propose a context-sensitive task migration model that recovers program states and rebinds resources for task migrations based on context semantics through inserting resource description and state description sections in source programs. Based on our model, we design and develop a task migration framework xMozart which extends the Mozart platform in terms of context awareness. Our approach can recover task states and rebind resources in the context-aware way, as well as support multi- modality I/O interactions. The extensive experiments demonstrate that our approach can migrate tasks by resuming them from the last broken points like shadows moving along with the users.

The development of a mobile decision support system

The emergence of mobile computing environments brings out various changes in the requirements and applications involving distributed data and has made the traditional Intelligent Decision Support System (IDSS) architectures based on the client/server model ineffective in mobile computing environments. This paper discusses the deficiencies of the current IDSS architectures based on data warehouse, on-line analysis processing (OLAP), model base (MB) and knowledge based (KB) technologies. By adopting the agent technology, the paper extends the IDSS system architecture to the Mobile Decision Support System (MDSS) architecture. The logical structure and the application architecture of the MDSS and the mechanisms and implementation strategies of the User Access Agent System, a major component of the MDSS, are described in this paper.

Efficient algorithm for mobile multicast using anycast group

The authors present a novel and efficient multicast algorithm that aims to reduce delay and communication cost for the registration between mobile nodes and mobility agents and solicitation for foreign agent services based on the mobile IP. The protocol applies anycast group technology to support multicast transmissions for both mobile nodes and home/foreign agents. Mobile hosts use anycast tunnelling to connect to the nearest available home/foreign agent where an agent is able to forward the multicast messages by selecting an anycast route to a multicast router so as to reduce the end-to-end delay. The performance analysis and experiments demonstrated that the proposed algorithm is able to enhance the performance over existing remote subscription and bidirectional tunnelling approaches regardless of the locations of mobile nodes/hosts

Transaction management in a replicated and mobile environment

Reports the design of three-level transaction processing model which provides efficient transaction management in a replicated and mobile environment. The model uses a promary/non-primary replication control protocol to enable transaction processing with fast user response time at any distributed site including mobile hosts. A Web-based design with an implementation of a prototype application system shows a concrete example of how to adopt the transaction model over distributed databases.

The implementation of mobile technology in organizations : expanding individual use contexts

Mobile computing devices such as personal digital assistants, smart mobile phones, and other handheld computing devices hold much promise in terms of their organizational application. Many existing models of the individual acceptance and implementation of information technology in organizational contexts have been developed in the era of “at the office” computing such as MIS, office automation, groupware, and so forth. We conducted two in-depth case studies of the implementation of mobile technology in healthcare organizations. The studies highlight interrelated individual use contexts due to the mobility of the technology: the individual as employee, as professional, as private user, and as member of society. The cases show that influences emanating from these use contexts impacted on the individual adoption of the technology within the organization. While broad extra-organizational influences are incorporated in some existing individual technology adoption models, we show that it becomes relevant to accommodate these influences more specifically in research models of mobile computing in organizations. Based on the extant literature and the case study data we pave the way toward more comprehensive models of the adoption and implementation of mobile technologies in organizations.