A Multi-Agent System Architecture for Sensor Networks

The design of the control systems for sensor networks presents important challenges. Besides the traditional problems about how to process the sensor data to obtain the target information, engineers need to consider additional aspects such as the heterogeneity and high number of sensors, and the flexibility of these networks regarding topologies and the sensors in them. Although there are partial approaches for resolving these issues, their integration relies on ad hoc solutions requiring important development efforts. In order to provide an effective approach for this integration, this paper proposes an architecture based on the multi-agent system paradigm with a clear separation of concerns. The architecture considers sensors as devices used by an upper layer of manager agents. These agents are able to communicate and negotiate services to achieve the required functionality. Activities are organized according to roles related with the different aspects to integrate, mainly sensor management, data processing, communication and adaptation to changes in the available devices and their capabilities. This organization largely isolates and decouples the data management from the changing network, while encouraging reuse of solutions. The use of the architecture is facilitated by a specific modelling language developed through metamodelling. A case study concerning a generic distributed system for fire fighting illustrates the approach and the comparison with related work

A Systematic Approach to Constructing Incremental Topology Control Algorithms Using Graph Transformation

Communication networks form the backbone of our society. Topology control algorithms optimize the topology of such communication networks. Due to the importance of communication networks, a topology control algorithm should guarantee certain required consistency properties (e.g., connectivity of the topology), while achieving desired optimization properties (e.g., a bounded number of neighbors). Real-world topologies are dynamic (e.g., because nodes join, leave, or move within the network), which requires topology control algorithms to operate in an incremental way, i.e., based on the recently introduced modifications of a topology. Visual programming and specification languages are a proven means for specifying the structure as well as consistency and optimization properties of topologies. In this paper, we present a novel methodology, based on a visual graph transformation and graph constraint language, for developing incremental topology control algorithms that are guaranteed to fulfill a set of specified consistency and optimization constraints. More specifically, we model the possible modifications of a topology control algorithm and the environment using graph transformation rules, and we describe consistency and optimization properties using graph constraints. On this basis, we apply and extend a well-known constructive approach to derive refined graph transformation rules that preserve these graph constraints. We apply our methodology to re-engineer an established topology control algorithm, kTC, and evaluate it in a network simulation study to show the practical applicability of our approachComment: This document corresponds to the accepted manuscript of the referenced journal articl

A Perspective on the Future of Middleware-based Software Engineering

International audienceMiddleware is a software layer that stands between the networked operating system and the application and provides well known reusable solutions to frequently encountered problems like heterogeneity, interoperability, security, dependability. Further, with networks becoming increasingly pervasive, middleware appears as a major building block for the development of future software systems. Starting with the impact of pervasive networking on computing models, manifested by now common grid and ubiquitous computing, this paper surveys related challenges for the middleware and related impact on the software development. Indeed, future applications will need to cope with advanced non-functional properties such as contextawareness and mobility, for which adequate middleware support must be devised together with accompanying software development notations, methods and tools. This leads us to introduce our view on next generation middleware, considering both technological advances in the networking area but also the need for closer integration with software engineering best practices, to ultimately suggest middleware-based software processes

Correct-by-Construction Development of Dynamic Topology Control Algorithms

Wireless devices are influencing our everyday lives today and will even more so in the future. A wireless sensor network (WSN) consists of dozens to hundreds of small, cheap, battery-powered, resource-constrained sensor devices (motes) that cooperate to serve a common purpose. These networks are applied in safety- and security-critical areas (e.g., e-health, intrusion detection). The topology of such a system is an attributed graph consisting of nodes representing the devices and edges representing the communication links between devices. Topology control (TC) improves the energy consumption behavior of a WSN by blocking costly links. This allows a mote to reduce its transmission power. A TC algorithm must fulfill important consistency properties (e.g., that the resulting topology is connected). The traditional development process for TC algorithms only considers consistency properties during the initial specification phase. The actual implementation is carried out manually, which is error prone and time consuming. Thus, it is difficult to verify that the implementation fulfills the required consistency properties. The problem becomes even more severe if the development process is iterative. Additionally, many TC algorithms are batch algorithms, which process the entire topology, irrespective of the extent of the topology modifications since the last execution. Therefore, dynamic TC is desirable, which reacts to change events of the topology. In this thesis, we propose a model-driven correct-by-construction methodology for developing dynamic TC algorithms. We model local consistency properties using graph constraints and global consistency properties using second-order logic. Graph transformation rules capture the different types of topology modifications. To specify the control flow of a TC algorithm, we employ the programmed graph transformation language story-driven modeling. We presume that local consistency properties jointly imply the global consistency properties. We ensure the fulfillment of the local consistency properties by synthesizing weakest preconditions for each rule. The synthesized preconditions prohibit the application of a rule if and only if the application would lead to a violation of a consistency property. Still, this restriction is infeasible for topology modifications that need to be executed in any case. Therefore, as a major contribution of this thesis, we propose the anticipation loop synthesis algorithm, which transforms the synthesized preconditions into routines that anticipate all violations of these preconditions. This algorithm also enables the correct-by-construction runtime reconfiguration of adaptive WSNs. We provide tooling for both common evaluation steps. Cobolt allows to evaluate the specified TC algorithms rapidly using the network simulator Simonstrator. cMoflon generates embedded C code for hardware testbeds that build on the sensor operating system Contiki

Modular DSLs for flexible analysis: An e-Motions reimplementation of Palladio

We address some of the limitations for extending and validating MDE-based implementations of NFP analysis tools by presenting a modular, model-based partial reimplementation of one well-known analysis framework, namely the Palladio Architecture Simulator. We specify the key DSLs from Palladio in the e-Motions system, describing the basic simulation semantics as a set of graph transformation rules. Di erent properties to be analysed are then encoded as separate, parametrised DSLs, independent of the de nition of Palladio. These can then be composed with the base Palladio DSL to generate speci c simulation environments. Models created in the Palladio IDE can be fed directly into this simulation environment for analysis. We demonstrate two main benefits of our approach: 1) The semantics of the simulation and the nonfunctional properties to be analysed are made explicit in the respective DSL speci cations, and 2) because of the compositional de nition, we can add de nitions of new non-functional properties and their analyses.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Model-based development for MAC protocols in industrial wireless sensor networks

Model-Driven Software Engineering (MDSE) is an approach for design and implementation of software applications, that can be applied across multiple domains. The advantages include rapid prototyping and implementation, along with reduction in errors induced by humans in the process, via automation. Wireless Sensor Actuator Networks (WSANs) rely on resource-constrained hardware and have platform-specific implementations. Medium Access Control (MAC) protocols in particular are mainly responsible for radio communication, the biggest consumer of energy, and are also responsible for Quality of Service (QoS). The design and development of protocols for WSAN could benefit from the use of MDSE. In this article, we use Coloured Petri Nets (CPN) for platform independent modeling of protocols, initial verification, and simulation. The PetriCode tool is used to generate platform-specific implementations for multiple platforms, including MiXiM for simulation and TinyOS for deployment. Further the generated code is analyzed via network simulations and real-world deployment test. Through the process of MDSE-based code generation and analysis, the protocol design is validated, verified and analyzed. We use the GinMAC protocol as a running example to illustrate the design and development life cycle.publishedVersionnivå

Autonomic Pervasive Applications Driven by Abstract Specifications

Conference in conjunction with ICAC 2012 (International Conference on Autonomic Computing)International audiencePervasive application architectures present stringent requirements that make their development especially hard. In particular, they need to be flexible in order to cope with dynamism in different forms (e.g. service and data providers and consumers). The current trend to build applications out of remote services makes the availability of constituent application components inherently dynamic. Developers can no longer assume that applications are static after development or at run time. Unfortunately, developing applications that are able to cope with dynamism is very complex.Existing development approaches do not provide explicit support for managing dynamism. In this paper we describe Rondo, a tool suite for designing pervasive applications. More specifically, we present our propositions in pervasive application specification, which borrows concepts from service-oriented component assembly, model-driven engineering (MDE) and continuous deployment, resulting in a more flexible approach than traditional application definitions. Then the capabilities of our application model are demonstrated with an example application scenario designed using our approach

Applying Software Product Lines to Build Autonomic Pervasive Systems

In this Master Thesis, we have proposed a model-driven Software Product Line (SPL) for developing autonomic pervasive systems. The work focusses on reusing the Variability knowledge from the SPL design to the SPL products. This Variability knowledge enables SPL products to deal with adaptation scenarios (evolution and involution) in an autonomic way.Cetina Englada, C. (2008). Applying Software Product Lines to Build Autonomic Pervasive Systems. http://hdl.handle.net/10251/12447Archivo delegad