Directory-based incentive management services for ad-hoc mobile clouds

Mobile cloud computing is envisioned as a promising approach to augment the computational capabilities of mobile devices for emerging resource-intensive mobile applications. This augmentation is generally achieved through the capabilities of stationary resources in cloud data centers. However, these resources are mostly not free and sometimes not available. Mobile devices are becoming powerful day by day and can form a self-organizing mobile ad-hoc network of nearby devices and offer their resources as on-demand services to available nodes in the network. In the ad-hoc mobile cloud, devices can move after consuming or providing services to one another. During this process, the problem of incentives arises for a node to provide service to another device (or other devices) in the network, which ultimately decreases the motivation of the mobile device to form an ad-hoc mobile cloud. To solve this problem, we propose a directory-based architecture that keeps track of the retribution and reward valuations (in terms of energy saved and consumed) for devices even after they move from one ad-hoc environment to another. From simulation results, we infer that this framework increases the motivation for mobile devices to form a self-organizing proximate mobile cloud network and to share their resources in the network

Supporting policy-based contextual reconfiguration and adaptation in ubiquitous computing

In order for pervasive computing systems to be able to perform tasks which support us in everyday life without requiring attention from the users of the environment, they need to adapt themselves in response to context. This makes context-awareness in general, and context-aware adaptation in particular, an essential requirement for pervasive computing systems. Two of the features of context-awareness are: contextual reconfiguration and contextual adaptation in which applications adapt their behaviour in response to context. We combine both these features of context-awareness to provide a broad scope of adaptation and put forward a system, called Policy-Based Contextual Reconfiguration and Adaptation (PCRA) that provides runtime support for both. The combination of both context-aware reconfiguration and context-aware adaptation provides a broad scope of adaptation and hence allows the development of diverse adaptive context-aware applications. However, another important issue is the choice of an effective means for developing, modifying and extending such applications. The main argument forming the basis of this thesis is that we advocate the use of a policy-based programming model and argue that it provides more effective means for developing, modifying and extending such applications. This thesis addresses other important surrounding issues which are associated with adaptive context-aware applications. These include the management of invalid bindings and the provision of seamless caching support for remote services involved in bindings for improved performance. The bindings may become invalid due to failure conditions that can arise due to network problems or migration of software components, causing bindings between the application component and remote service to become invalid. We have integrated reconfiguration support to manage bindings, and seamless caching support for remote services in PCRA. This thesis also describes the design and implementation of PCRA, which enables development of adaptive context-aware applications using policy specifications. Within PCRA, adaptive context-aware applications are modelled by specifying binding policies and adaptation policies. The use of policies within PCRA simplifies the development task because policies are expressed at a high-level of abstraction, and are expressed independently of each other. PCRA also allows the dynamic modification of applications since policies are independent units of execution and can be dynamically loaded and removed from the system. This is a powerful and useful capability as applications may evolve over time, i.e. the user needs and preferences may change, but re-starting is undesirable. We evaluate PCRA by comparing its features to other systems in the literature, and by performance measures

Contextual mobile adaptation

Ubiquitous computing (ubicomp) involves systems that attempt to fit in with users’ context and interaction. Researchers agree that system adaptation is a key issue in ubicomp because it can be hard to predict changes in contexts, needs and uses. Even with the best planning, it is impossible to foresee all uses of software at the design stage. In order for software to continue to be helpful and appropriate it should, ideally, be as dynamic as the environment in which it operates. Changes in user requirements, contexts of use and system resources mean software should also adapt to better support these changes. An area in which adaptation is clearly lacking is in ubicomp systems, especially those designed for mobile devices. By improving techniques and infrastructure to support adaptation it is possible for ubicomp systems to not only sense and adapt to the environments they are running in, but also retrieve and install new functionality so as to better support the dynamic context and needs of users in such environments. Dynamic adaptation of software refers to the act of changing the structure of some part of a software system as it executes, without stopping or restarting it. One of the core goals of this thesis is to discover if such adaptation is feasible, useful and appropriate in the mobile environment, and how designers can create more adaptive and flexible ubicomp systems and associated user experiences. Through a detailed study of existing literature and experience of several early systems, this thesis presents design issues and requirements for adaptive ubicomp systems. This thesis presents the Domino framework, and demonstrates that a mobile collaborative software adaptation framework is achievable. This system can recommend future adaptations based on a history of use. The framework demonstrates that wireless network connections between mobile devices can be used to transport usage logs and software components, with such connections made either in chance encounters or in designed multi–user interactions. Another aim of the thesis is to discover if users can comprehend and smoothly interact with systems that are adapting. To evaluate Domino, a multiplayer game called Castles has been developed, in which game buildings are in fact software modules that are recommended and transferred between players. This evaluation showed that people are comfortable receiving semi–automated software recommendations; these complement traditional recommendation methods such as word of mouth and online forums, with the system’s support freeing users to discuss more in–depth aspects of the system, such as tactics and strategies for use, rather than forcing them to discover, acquire and integrate software by themselves

A framework for offloading decision making to conserve battery life on mobile devices

Abstract: The increased use of mobile devices has led to the creation of complex mobile applications that require more resources than are readily available on mobile devices. As resources such as processing power and storage are found on the cloud, resources of mobile devices can be increased by using cloud-based mobile augmentation. However, some resources, specifically battery life, and bandwidth cannot be augmented. To augment mobile device resources such as battery life, offloading can be used. This research discusses offloading methods and examines the approaches used in related research. It is found that most of the energy consumed when offloading is due to network communication, as opposed to computation when executing locally. When offloading to the cloud consumes less energy than local execution, the battery life of a mobile device can be conserved. Choosing between offloading and local execution is called an offloading decision. To make offloading decisions that conserve battery life, the decision-making process is explored. A challenge identified when making offloading decisions is accurately estimating the energy consumption of tasks when offloading and when executing locally. As the energy consumption profile of each device differs according to the capabilities of the device, this aspect is explored. The research conducted in this dissertation proposes the Switch framework. The Switch framework conserves the limited battery life on mobile devices by estimating the consumption of energy of a task and choosing the least expensive option. A software-based device-specific energy consumption profile is created for this purpose. Switch is evaluated using the Switch prototype, which has been designed according to the specifications of the framework. The prototype is evaluated by comparing the estimated energy consumption against the measured energy consumption. The evaluation of the framework suggests that Switch can successfully be used to conserve battery life on mobile devices by making intelligent offloading decisions.M.Sc. (Information Technology

Simplifying interaction on mobile devices using context-aware computing

This thesis investigates how context-awareness and learning from user patterns could improve the user interaction for a smartphone applica- tion that can control the computer and home and how it could create a smarter more personal experience. It looks at both how a existing cus- tomers would react in three different experiments (a survey, interviews and a prototype of the application), and how non-users would like an application that could control their home with respect to context- awareness. In the experiment carried out on the non-users a web- based simulator was used to illustrate the different levels of awareness during an interview where the different scenarios were discussed and compared. It finds that that the existing customers were interested in creating a more personal experience by adding context-awareness and learning user patterns. In addition, it finds that a majority of the non- customers would like as much automation as possible