Towards Self-evolving Context-aware Services

The introduction of new communication infrastructures such as Beyond 3rd Generation (B3G) and the widespread usage of small computing devices are rapidly changing the way we use and interact with technology to perform everyday tasks. Ubiquitous networking empowered by B3G networking makes it possible for mobile users to access networked software services across continuously changing heterogeneous infrastructures by resource-constrained devices. Heterogeneity and devices' limitedness, create serious problems for the development and dynamic deployment of mobile applications that are able to run properly on the execution context and consume services matching with the users' expectations. Furthermore, the everchanging B3G environment calls for applications that self-evolve according to context changes. Out of these problems, self-evolving adaptable applications are increasingly emerging in the software community. In this paper we describe how CHAMELEON, a declarative framework for tailoring adaptable applications, is being used for tackling adaptation and self-evolution within the IST PLASTIC project

PLASTIC: Providing lightweight & adaptable service technology for pervasive information & communication

International audienceThe PLASTIC project adopts and revisits serviceoriented computing for Beyond 3rd Generation (B3G) networks, in particular aiming at assisting the development of services targeted at mobile devices. Specifically, PLASTIC introduces the PLASTIC platform to enable robust distributed lightweight services in B3G networking environments through: • A development environment for the thorough development of SLA- and resource-aware services, which may be deployed on the various networked nodes, including handheld devices; • A service-oriented middleware leveraging multiradio devices and multi-network environments for applications and services deployed on mobile devices, further enabling context-aware and secure discovery and access to such services; • A validation framework enabling off-line and online validation of networked services regarding functional and non-functional properties

A Reference Model for Service Oriented Middleware

From the software engineering perspective, the notion of Service Oriented Architecture (SOA) has been receiving significant attention within the software design and development community. This attention has led to the proliferation of conflicting characterizations of SOA, resulting in an ambiguous understanding of SOA entities and relationships among them. To achieve a common understanding, OASIS and SeCSE propose reference models that introduce a comprehensive ontology for modeling software services around the well known service-oriented interaction pattern. However OASIS and SeCSE models abstract the actual interaction pattern runtime support, which is generally provided by a Service Oriented Middleware (SOM). In this paper we propose a reference model for architecting SOM solutions over next generation networking environment and evaluate it by designing a conforming lower-level model for the SOM developed for the PLASTIC project

Mobility management in B3G networks: a middleware-based approach

International audienceThe B3G (Beyond 3G) networking will enable mobile users to roam freely through heterogeneous networks on an all-IP platform. However, mobility handling in such an environment poses new challenges. Traditionally, mobility protocols such as Mobile IP, SIP and SCTP are used to manage mobility in B3G, but they require telecommunication companies to either modify existing network infrastructures or deploy central entities in the network core to handle mobility. This is not feasible in a fully distributed computing environment (e.g., P2P) and mobile ad hoc networks that are part of B3G networking. As an alternative, this paper introduces a middleware component with modularized functionalities to facilitate mobility management in a fully distributed B3G environment

Energetic Performance of Service-oriented Multi-radio Networks: Issues and Perspectives

Wireless devices now hold multiple radio interfaces, allowing to switch from one network to another according to required connectivity and related quality. Still, the selection of the best radio interface for a specific connection is under the responsibility of the end-user in most cases. Integrated multi-radio network management so as to improve the overall performance of the network(s) has led to a number of research efforts over the last few years. However, several challenges remain due to the inherent complexity of the problem. This paper specifically concentrates on the comprehensive analysis of energy-efficient multi-radio networking for pervasive computing. Building upon the service oriented architectural style, we consider pervasive networks of services, which are deployed on the various networked nodes. The issue is then to optimize the energetic performance of the pervasive network through careful selection of the radio link over which service access should be realized for each such access. This leads us to examine first the energetic performance of service access for most common wireless interfaces in use today (Bluetooth, WiFi and GPRS) and then introduce a formal model of service-oriented multi-radio networks. The proposed model enables characterizing the optimal network configuration in terms of energetic performance, which is shown to be a NP-hard problem and thus requires adequate approximation

Run Time Models in Adaptive Service Infrastructure

Software in the near ubiquitous future will need to cope with vari- ability, as software systems get deployed on an increasingly large diversity of computing platforms and operates in different execution environments. Heterogeneity of the underlying communication and computing infrastruc- ture, mobility inducing changes to the execution environments and therefore changes to the availability of resources and continuously evolving requirements require software systems to be adaptable according to the context changes. Software systems should also be reliable and meet the user's requirements and needs. Moreover, due to its pervasiveness, software systems must be de- pendable. Supporting the validation of these self-adaptive systems to ensure dependability requires a complete rethinking of the software life cycle. The traditional division among static analysis and dynamic analysis is blurred by the need to validate dynamic systems adaptation. Models play a key role in the validation of dependable systems, dynamic adaptation calls for the use of such models at run time. In this paper we describe the approach we have un- dertaken in recent projects to address the challenge of assessing dependability for adaptive software systems

A flexible QoS-aware routing protocol for infrastructure-less B3G networks

International audienceCurrent mobile devices support multiple network technolo- gies and network composition via such devices can enable service provisioning across heterogeneous networks. One of the key challenges for realizing this view is inter-domain routing. Indeed, given the diversity of involved network technologies and infrastructures, a exible routing protocol that takes into account their quality properties and dynam- ics is an important requirement. In this paper, we present a exible quality-aware routing protocol for infrastructure-less B3G environments that enables discovery of routes with op- timal bandwidth, delay or cost according to the preference of each client. The protocol is based on the Optimized Link- State Routing (OLSR) protocol and is designed to enable computation of quality-aware routes in multi-network envi- ronments. We detail the protocol, discuss its deployment and provide experimental results

Interoperability of Service Discovery Protocols: Transparent versus Explicit Approaches

International audienceDiscovering networked services in pervasive computing environments is problematic as multiple Service Discovery Protocols (SDPs), differing on their services description formats as well as advertisement and request models, have already become (de-facto) standards. This calls for a solution to SDP interoperability, enabling clients to locate networked services independent of the SDP they use to advertise their presence. In this paper, we report on our experience in developing two such solutions: the transparent approach of INDISS based on message translation, and the explicit approach of MSDA based on protocol integration. While efficient and able to support legacy clients and services, INDISS is limited by the basic service information available in existing SDPs, and assumptions about the network protocols used by the SDPs. Advanced discovery features required by pervasive environments, such as context or security management, can only be provided by more complex discovery frameworks like MSDA, but come at a price

ubiSOAP: A Service Oriented Middleware for Ubiquitous Networking

International audienceThe computing and networking capacities of today's wireless portable devices allow for ubiquitous services, which are seamlessly networked. Indeed, wireless handheld devices now embed the necessary resources to act as both service clients and providers. However, the ubiquitous networking of services remains challenged by the inherent mobility and resource constraints of the devices, which make services a priori highly volatile. This paper discusses the design, implementation and experimentation of the ubiSOAP service-oriented middleware, which leverages wireless networking capacities to effectively enable the ubiquitous networking of services. ubiSOAP specifically defines a layered communication middleware that underlies standard SOAP-based middleware, hence supporting legacy Web Services while exploiting nowadays ubiquitous connectivity