Abstract. A new field in distributed computing, called Ambient Intelligence, has emerged as a consequence of the increasing availability of wireless devices and the mobile networks they induce. Developing software for mobile networks is extremely hard in conventional programming languages because the network is dynamically demarcated. This leads us to postulate a suite of characteristics of future Ambient-Oriented Programming languages. A simple reflective programming language, called AmbientTalk, that meets the characteristics is presented. It is validated by implementing a collection of high level language features that are used in the implementation of an ambient messenger application. 1

A new field in distributed computing, called Ambient Intelligence, has emerged as a consequence of the increasing availability of wireless devices and the mobile networks they induce. Developing software for such mobile networks is extremely hard in conventional programming languages because the network is dynamically defined. This hardware phenomenon leads us to postulate a suite of characteristics of future Ambient-Oriented Programming languages. A simple reflective programming language kernel, called AmbientTalk, that meets these characteristics is subsequently presented. The power of the reflective kernel is illustrated by using it to conceive a collection of high level tentative ambient-oriented programming language features.

Abstract: In distributed and mobile environments, the connections among the hosts on which a software system is running are often unstable. As a result of connectivity losses, the overall availability of the system decreases. The distribution of software components onto hardware nodes (i.e., deployment architecture) may be ill-suited for the given target hardware environment and may need to be altered to improve the software system’s availability. The critical difficulty in achieving this task lies in the fact that determining a software system’s deployment that will maximize its availability is an exponentially complex problem. In this paper, we present an automated, flexible, software architecturebased solution for disconnected operation that increases the availability of the system during disconnection. We provide a fast approximative solution for the

With their increasingly powerful computational resources and high-speed wireless communications, future mobile systems will have the ability to run sophisticated applications on collections of cooperative end devices. Mobility, however, requires dynamic management of these platforms’ distributed resources, and such management can also be used to meet application quality requirements and prolong application lifetimes, the latter by best using available energy resources. This paper presents energy-aware Mobile Service Overlays (MSOs), a set of mechanisms and associated policies for running mobile applications across multiple, cooperating machines while actively performing power management to extend system usability lifetimes. MSO policies manage energy consumption by (i) allocating application components to available nodes based upon their current energy capacities and resource availabilities, (ii) monitoring for, and responding to changes in energy and resource characteristics, and (iii) dynamically exploiting energy-performance tradeoffs in overprovisioned situations. Coupled with mobility, such cooperation enables multiple mobile platforms to bring their joint resources to bear on complex application tasks, providing significant benefits to application lifetimes and performance. Evaluations of MSOs on a MANET computing testbed indicate an extension in system lifetime of upto 10 % for an example application. 1

no The operating context of mobile applications and services is constantly changing. In order to achieve higher levels of usability, mobile applications and services need to adapt to changes in context. This paper argues the need for adaptation enabling middleware that simplifies the development of context aware adaptive applications, and makes it economically and practically feasible to develop such applications. We claim that the traditional approach of simply providing contextual information to applications and let them handle the adaptation can be ineffective. We suggest a holistic approach where context management is an integral part of a more comprehensive adaptation enabling middleware. This paper describes the role and the design of the context management component in such a middleware architecture. The feasibility of the approach is demonstrated in a scenario where proof-of-concept implementations have been developed and evaluated. 1.

Abstract—In this paper, we describe AmbientTalk: a domainspecific language for orchestrating service discovery and composition in mobile ad hoc networks. AmbientTalk is a distributed object-oriented programming language whose actor-based, eventdriven concurrency model makes it highly suitable for composing service objects across a mobile network. The language is a so-called ambient-oriented programming language which treats network partitions as a normal mode of operation. We describe AmbientTalk’s object model, concurrency model and distributed communication model in detail. We also highlight the major influences from other languages and middleware that have shaped AmbientTalk’s design. Index Terms—distributed languages, actors, events, publish/subscribe, service discovery, service composition, mobile networks, pervasive computing I.

In this paper we propose an approach to support dynamic or runtime variability in systems that must adapt dynamically to changing runtime context. The approach is founded on reflective component-based technologies to support the dynamic variability at the architectural level. Adaptive behaviour is encoded in reconfiguration policies that are consulted at run-time when changes in the underlying environment are detected. Specifically, the reconfiguration policies dictate the component-based architecture to be used in actively changing contexts. However, the increasing number of variants and their interdependency relationships add to the complexity of variability management. Therefore, the paper also proposes a notation and associated models to address the management of dynamic variability. We describe our experience with applying this approach through a case study; the support and management of dynamic variability for service discovery protocols.

Abstract—In this paper we report about our experience in using mobile computing middleware in context of health-care. The dynamicity and variability of context and conditions make this environment very suitable for the use of mobile and wearable computing techniques. The use of small and portable devices can be very beneficial in terms of efficiency and vital support to patients. However, the many challenges that this environment presents need to be addressed, possibly by a general mobile computing framework that could be used in different mobile settings. We will discuss these issues in the paper along with the description of the prototype we have developed. 1

Many context-aware computing applications form inferences and execute corresponding actions based on context that is uniquely associated with a user. We refer to such applications as customized context-aware applications and recognize that their design poses a very challenging burden to application designers due to the degree of customization that is required. To tackle this problem, we propose to develop a programming model and framework for context-aware applications with the goal of shielding application developers from the complexity of customization. The framework applies machine learning in novel ways to infer application triggering conditions. This paper presents the key research challenges that must be overcome to reach this goal along with the directions that we are currently exploring.

Mobile computing systems have non-functional properties that differ from fixed distributed systems due to the radio and mobile terminal characteristics. Traditional middleware does not manage these non-functional properties. Hence, the middleware must be designed specifically for mobile computing. Existing mobile middleware platforms and state-of-the-art research focus on handling network quality of service (QoS). There is limited attention on a general approach to QoS that takes into consideration the QoS characteristics of both end-systems and the mobile communication system. This article presents a general QoS framework with QoS specific elements for mobile middleware, which combines and extends existing QoS frameworks. Following this, we use the QoS framework to systematically and qualitatively compare and discuss state-of-the-art QoS-aware mobile middleware platforms. In general, existing work sets a firm baseline for future research. A potential area within mobile middleware that needs more research is QoS architectures that can incorporate new and existing QoS mechanisms to adapt application and middleware to context changes and resource fluctuations. Keywords: Mobile middleware; Reflective middleware; QoS mechanisms; QoS-aware adaptation; Dynamic service reconfiguration;