CiAN: A Language and Middleware for Collaboration in Ad hoc Networks

Designing software that supports collaboration among multiple users in mobile ad hoc networks is challenging due to the dynamic network topology and inherent unpredictability of the environment. However, as we increasingly migrate to using mobile computing platforms, there is a pertinent need for software that can support a wide range of collaborative activities anywhere and at any time without relying on any external infrastructure. In this paper, we adopt the workflow model to represent the structure of an activity that involves multiple tasks being performed in a structured, collaborative fashion by multiple users. Using the workflow model as a base, we developed an XML based specification language called CiAN that can be used to build workflows that can be fragmented and distributed across the hosts of participating users so that the collaborative activity is executed in a distributed manner. The tasks specified in the CiAN language are executed by our Java based CiAN middleware, which runs on mobile hosts. Communication of task results between hosts occurs via a novel protocol that uses the workflow structure to make routing decisions on data packets. Complete implementation details and an evaluation of our approach are also presented

Service Replication in Wireless Mobile Ad Hoc Networks

Die vorliegende Arbeit beschäftigt sich mit dem Management von Diensten im mobilen ad-hoc Netzwerken (MANETs). MANETs sind drahtlose Netzverbände mobiler Einheiten die sich dezentral ohne eine übergeordnete Organisation selbst verwalten. Die Netztopologie eines MANET verändert sich dabei dynamisch mit der Bewegung der autonomen Teilnehmer. Sensor Netzwerke, Personal Area Networks und Satelliten Netzwerke sind typische Beispiele für derartige MANETs. Mit der wachsenden Bedeutung der drahtlosen Vernetzung mobiler Geräte haben sich MANETs in den vergangenen Jahren zu einem wichtigen Forschungsgebiet entwickelt. Im Katastrophenmanagement, bei zivilen Rettungsfällen oder in militärischen Szenarien kann ihre infrastrukturlose Selbstorganisation MANETs zum einzig möglichen Kommunikationsmittel machen. Die mobilen Knoten eines MANETs kooperieren um essenzielle Netzwerkdienste wie das Routing und den Datentransport gemeinschaftlich zu gewährleisten. Ressourcen wie die Bandbreite zwischen Knoten, die Rechenleistung der mobilen Geräte und ihre Batterieleistung sind dabei typischerweise stark begrenzt und zudem wechselnd. Das Teilen der verfügbaren Ressourcen ist daher eine Notwendigkeit für das effiziente Funktionieren eines MANETs. Dienstorientierte Architekturen (SOAs) stellen ein geeignetes Paradigma dar, um geteilte Ressourcen zu verwalten. Wenn verfügbare Ressourcen als Dienst aufgefasst werden, lässt sich ihre Nutzung als Dienstabfrage bearbeiten. In diesem Zusammenhang ermöglichen SOAs Abstraktion, Kapselung, lose Koppelung, Auffindbarkeit von Ressourcen und dir für MANETs essenzielle Autonomie. Die Anwendung von SOAs auf MANETs findet daher zunehmend Beachtung in der Forschung

Supporting Collaboration in Mobile Environments

Continued rapid improvements in the hardware capabilities of mobile computing devices is driving a parallel need for a paradigm shift in software design for such devices with the aim of ushering in new classes of software applications for devices of the future. One such class of software application is collaborative applications that seem to reduce the burden and overhead of collaborations on human users by providing automated computational support for the more mundane and mechanical aspects of a cooperative effort. This dissertation addresses the research and software engineering questions associated with building a workflow-based collaboration system that can operate across mobile ad hoc networks, the most dynamic type of mobile networks that can function without dependence on any fixed external resources. While workflow management systems have been implemented for stable wired networks, the transition to a mobile network required the development of a knowledge management system for improving the predictability of the network topology, a mobility-aware specification language to specify workflows, and its accompanying algorithms that help automate key pieces of the software. In addition to details of the formulation, design, and implementation of the various algorithms and software components. this dissertation also describes the construction of a custom mobile workflow simulator that can be used to conduct simulation experiments that verify the effectiveness of the approaches presented in this document and beyond. Also presented are empirical results obtained using this simulator that show the effectiveness of the described approaches

GOSSIPKIT: A Unified Component Framework for Gossip

International audienceAlthough the principles of gossip protocols are relatively easy to grasp, their variety can make their design and evaluation highly time consuming. This problem is compounded by the lack of a unified programming framework for gossip, which means developers cannot easily reuse, compose, or adapt existing solutions to fit their needs, and have limited opportunities to share knowledge and ideas. In this paper, we consider how component frameworks, which have been widely applied to implement middleware solutions, can facilitate the development of gossip-based systems in a way that is both generic and simple. We show how such an approach can maximise code reuse, simplify the implementation of gossip protocols, and facilitate dynamic evolution and re-deployment

04411 Abtracts Collection -- Service Management and Self-Organization in IP-based Networks

From 03.10.04 to 06.10.04, the Dagstuhl Seminar 04411 ``Service Management and Self-Organization in IP-based Networks\u27\u27 was held in the International Conference and Research Center (IBFI), Schloss Dagstuhl. During the seminar, several participants presented their current research, and ongoing work and open problems were discussed. Abstracts of the presentations given during the seminar as well as abstracts of seminar results and ideas are put together in this paper. The first section describes the seminar topics and goals in general. Links to extended abstracts or full papers are provided, if available

Constructing distributed time-critical applications using cognitive enabled services

Time-critical analytics applications are increasingly making use of distributed service interfaces (e.g., micro-services) that support the rapid construction of new applications by dynamically linking the services into different workflow configurations. Traditional service-based applications, in fixed networks, are typically constructed and managed centrally and assume stable service endpoints and adequate network connectivity. Constructing and maintaining such applications in dynamic heterogeneous wireless networked environments, where limited bandwidth and transient connectivity are commonplace, presents significant challenges and makes centralized application construction and management impossible. In this paper we present an architecture which is capable of providing an adaptable and resilient method for on-demand decentralized construction and management of complex time-critical applications in such environments. The approach uses a Vector Symbolic Architecture (VSA) to compactly represent an application as a single semantic vector that encodes the service interfaces, workflow, and the time-critical constraints required. By extending existing services interfaces, with a simple cognitive layer that can interpret and exchange the vectors, we show how the required services can be dynamically discovered and interconnected in a completely decentralized manner. We demonstrate the viability of this approach by using a VSA to encode various time-critical data analytics workflows. We show that these vectors can be used to dynamically construct and run applications using services that are distributed across an emulated Mobile Ad-Hoc Wireless Network (MANET). Scalability is demonstrated via an empirical evaluation

A Low-Latency Service Composition Approach in Mobile Ad Hoc Networks

International audienceIn order to offer complex services to the users, separate services located at different devices in MANET should be composed in a mobile ad hoc network. A distributed approach to search for the Service Composition Path (SCP) with a low latency is proposed, which is based on two methods, Path Filtering and Path Combination. These two methods avoid unnecessary message transmissions, and greatly improve the searching efficiency. The experiment results show the superiorities of the approach to its counterpart