Design and prototyping of real-time systems using CSP and CML

A procedure for systematic design of event based systems is introduced by means of the Production Cell case study. The design is documented by CSP-style processes, which allow both verification using formal techniques and also validation of a rapid prototype in the functionallanguage CML. 1. Introduction Notations like CSP [1] or CCS [2] provide concise notations for documenting the design of reactive or real-time systems. These notations further allow verification of properties through calculation, or model checking [3]. Yet there is a sizable gap from such specifications to executable programs needed to validate or test the design [4, 5, 6, 7]. In this paper we demonstrate how this gap is closed by CML [8], an extension of ML [9]. As shown in this paper, it is easy to get from a CSP design to an executable CML program, and the program can be interfaced to programs in other programming languages. We illustrate this idea by applying the design method for real-time systems presented in..

Characteristics of Real-Time, Non-Critical Incident Debriefing Practices in the Emergency Department.

INTRODUCTION: Benefits of post-simulation debriefings as an educational and feedback tool have been widely accepted for nearly a decade. Real-time, non-critical incident debriefing is similar to post-simulation debriefing; however, data on its practice in academic emergency departments (ED), is limited. Although tools such as TeamSTEPPS® (Team Strategies and Tools to Enhance Performance and Patient Safety) suggest debriefing after complicated medical situations, they do not teach debriefing skills suited to this purpose. Anecdotal evidence suggests that real-time debriefings (or non-critical incident debriefings) do in fact occur in academic EDs;, however, limited research has been performed on this subject. The objective of this study was to characterize real-time, non-critical incident debriefing practices in emergency medicine (EM). METHODS: We conducted this multicenter cross-sectional study of EM attendings and residents at four large, high-volume, academic EM residency programs in New York City. Questionnaire design was based on a Delphi panel and pilot testing with expert panel. We sought a convenience sample from a potential pool of approximately 300 physicians across the four sites with the goal of obtaining \u3e100 responses. The survey was sent electronically to the four residency list-serves with a total of six monthly completion reminder emails. We collected all data electronically and anonymously using SurveyMonkey.com; the data were then entered into and analyzed with Microsoft Excel. RESULTS: The data elucidate various characteristics of current real-time debriefing trends in EM, including its definition, perceived benefits and barriers, as well as the variety of formats of debriefings currently being conducted. CONCLUSION: This survey regarding the practice of real-time, non-critical incident debriefings in four major academic EM programs within New York City sheds light on three major, pertinent points: 1) real-time, non-critical incident debriefing definitely occurs in academic emergency practice; 2) in general, real-time debriefing is perceived to be of some value with respect to education, systems and performance improvement; 3) although it is practiced by clinicians, most report no formal training in actual debriefing techniques. Further study is needed to clarify actual benefits of real-time/non-critical incident debriefing as well as details on potential pitfalls of this practice and recommendations for best practices for use

Optimal Alignments for Designing Urban Transport Systems: Application to Seville

The achievement of some of the Sustainable Development Goals (SDGs) from the recent 2030 Agenda for Sustainable Development has drawn the attention of many countries towards urban transport networks. Mathematical modeling constitutes an analytical tool for the formal description of a transportation system whereby it facilitates the introduction of variables and the definition of objectives to be optimized. One of the stages of the methodology followed in the design of urban transit systems starts with the determination of corridors to optimize the population covered by the system whilst taking into account the mobility patterns of potential users and the time saved when the public network is used instead of private means of transport. Since the capture of users occurs at stations, it seems reasonable to consider an extensive and homogeneous set of candidate sites evaluated according to the parameters considered (such as pedestrian population captured and destination preferences) and to select subsets of stations so that alignments can take place. The application of optimization procedures that decide the sequence of nodes composing the alignment can produce zigzagging corridors, which are less appropriate for the design of a single line. The main aim of this work is to include a new criterion to avoid the zigzag effect when the alignment is about to be determined. For this purpose, a curvature concept for polygonal lines is introduced, and its performance is analyzed when criteria of maximizing coverage and minimizing curvature are combined in the same design algorithm. The results show the application of the mathematical model presented for a real case in the city of Seville in Spain.Ministerio de Economía y Competitividad MTM2015-67706-

Incorporating faults and fault-tolerance into real-time networks: a graph-transformational approach

PhD ThesisThe introduction of fault tolerance into real-time systems presents particular challenges because of the price of redundancy and the added complexity of verification and validation on these redundant structures. This thesis brings structural and formal design techniques to bear on this problem. Verification of fault tolerance properties in such systems has only received limited attention. in particular the design methodologies are in their infancy. We propose a transformational design methodology, specific to a real-time systems architecture. We then reason about the compositional addition of fault tolerant components and templates of the derived designs. This requires that we show the existing axiomatic semantics for our chosen architecture sound with respect to a more constructive semantic model. The issues of presenting an operational model for a real-time architecture are discussed and a model is proposed. The extension of the existing semantics, to allow for faulty behaviour, is shown to preserve the existing semantic properties and the application of our methodology shown to be usable by a sizeable study. The contribution of this thesis is to define a transformational design methodology in which components can be extracted from a design and replaced by another component preserving functionality while providing fault tolerance. This approach requires the precise modelling of the faults we consider. the transformational method and verification of the transformed design with respect to faults.BAE Systems: EPSRC

COntinuuM, a CO-modelling Methodology for the Integration of Real-time Architecture Models

International audienceThe design of Distributed Real-time Embedded (DRE) architecture models for complex and critical systems with safety, liveness, timeliness, dependability concerns, forces the use of formal languages. Because of the high level of criticity, proof techniques are required instead of model-checking with limitations relatively to the state space explosion problems. Proofs of these non-functional properties can only be established on the basis of formal languages with high verification capabilities (theorem provers).Therefore, we have concentrated our efforts on the development of a methodology that would better integrate formal aspects into the design of DRE architectures, which is usually based upon the use of (semi-formal) Architecture Design Languages (ADLs). This methodology has both to support the traceability of non-functional property proofs (from the requirements to the deployment of a DRE system) and the integration of formal and non formal modelling languages.The approach is bottom-up when the method states that each realization artifact, even hidden, has to be detected from the capture requirement stage (each possible realization artifact has to be identified during a prototype coding stage) As a consequence, language translations are not based on the MDA process that supposes some projections. These projections would be responsible for the gap between abstractions used to understand and describe the problem and those used for implementation. To bridge those gaps is the major aim of the methodology, so we called it “Continuum” as it would help to restore the development process continuity. The new aspects of this methodology (and its difficulties) are essentially the introduction of low level concepts (needed for the implementation stages) into the modeling language structures, usually more generic. The methodology application is the development of an algorithmic language translator that enable the generation of a safe code

사이버-물리 시스템을 위한 기능적/시간적 정확성 보장 시뮬레이션 기법

학위논문 (박사)-- 서울대학교 대학원 공과대학 전기·컴퓨터공학부, 2017. 8. 이창건.When developing a Cyber-Physical System (CPS), simulators are commonly used to predict the final performance of the system at the design phase. However, current simulation tools do not consider timing behaviors of the cyber-system such as varying execution times and task preemptions. Thus, their control performance predictions are far different from the real performance, and this leads to enormous time and cost for a system development, because multiple re-design and re-implementation phases are required, until an acceptable system configuration is determined. Motivated by this limitation, this dissertation proposes functionally and temporally correct simulation for the cyber-side of a CPS. The key idea of the proposed approach is to keep the data and time correctness only at the physical interaction points to maximally enjoy the freedom of scheduling simulated jobs. For this, we transform the simulation problem to a real-time job scheduling problem with precedence constraints necessary for the functional and temporal correctness. Then, we propose an efficient scheduling algorithm for the functionally and temporally correct real-time simulation. The proposed approach significantly improves the real-time simulation capacity of the state-of-the-art simulation methods while keeping the functional and temporal correctness. Our evaluation through both synthetic workload and actual implementation confirms both high accuracy and high efficiency of our approach compared with other state-of-the-art methods.1 Introduction 1 1.1 Motivation and Objective 1 1.2 Approach 3 1.3 Contributions 8 1.4 Organization 8 2 Related Work 10 2.1 Design and Verification of Cyber-Physical Systems 10 2.2 Verification Approaches 12 2.2.1 Model-Based Simulations 12 2.2.2 Cycle-Accurate Simulations and Host-Compiled Simulations 14 2.2.3 Real-Time Execution Platforms 15 2.2.4 Distributed Simulations 16 2.3 Job Scheduling Approaches 17 3 System Model and Problem Description 22 3.1 Description on the real cyber-system 23 3.2 Description on the simulated cyber-system 27 3.3 Formal definition of the simulation problem 28 4 Real-Time Simulation for Deterministic Cyber-Systems 31 4.1 Introduction 31 4.2 Construction of Offline Guider 31 4.3 Online Progressive Scheduling of Simulated Jobs 34 4.4 Evaluation 38 5 Real-Time Simulation for Non-Deterministic Cyber-Systems 45 5.1 Introduction 45 5.2 Overview of Approach 45 5.3 Construction of Offline Guider 50 5.4 Online Progressive Scheduling of Simulated Jobs 63 5.5 Evaluation 74 5.5.1 Evaluation Using Synthesized Cyber-Systems 78 5.5.2 Implementation 86 6 Practical Discussions 95 6.1 Data Exchange Delay 95 6.2 Simulation Overhead 97 6.2.1Offline Overhead 97 6.2.2 Online Overhead 100 6.3 Other Useful Features 100 7 Extension for Multicore Simulation PC 102 8 Conclusion 108 8.1 Summary 108 8.2 Future Work 108 References 110Docto

Rail Internet of Things: An Architectural Platform and Assured Requirements Model

Given the plethora of individual preferences and requirements of public transport passengers for travel, seating, catering, etc., it becomes very challenging to tailor generic services to individuals’ requirements using the existing service platforms. As tens of thousands of sensors have been already deployed along roadsides and rail tracks, and on buses and trains in many countries, it is expected that the introduction of IP networking will revolutionise the functionality of public transport in general and rail services in particular. In this paper, we propose a new communication paradigm to improve rail services and address the requirement of rail service users: the Rail Internet of Things (RIoT). To the best of our knowledge, it is the first work to define the RIoT and design an architectural platform that includes its components and the data communication channels. Moreover, we develop an assured requirements model using the situation calculus modelling to represent the fundamental requirements for adjustable, decentralised feedback control mechanisms necessary for the RIoT-ready software systems. The developed formal model is applied to demonstrate the design of passenger assistance software that interacts with the RIoT ecosystem and provides passengers with real-time information that is tailored to their requirements with runtime adaptability. Keywords—Assistance; Assured model; Inclusive; IoT; Rail Internet of Things (RIoT); Situation Calculu

Towards Time-triggered Component-based System Models

International audienceIn this paper, we propose a methodology for producing correct-by-construction Time-Triggered (TT) physical model by starting from a high-level model of the application software in Behaviour, Interaction, Priority (BIP). BIP is a component-based framework with formal semantics that rely on multi-party interactions for synchronizing components. Commonly in TT implementations, processes interact with each other through a communication medium. Our methodology transforms, depending on a user-defined task mapping, high-level BIP models where communication between components is strongly synchronized, into TT physical model that integrates a communication medium. Thus, only inter-task communications and components participating in such interactions are concerned by the transformation process. The transformation consists of: (1) breaking atomicity of actions in components by replacing strong synchronizations with asynchronous send/receive interactions, (2) inserting communication media that coordinate execution of inter-task interactions according to a user-defined task mapping, (3) extending the model with an algorithm for handling conflicts between different communication media and (4) instantiating task components and adding local priority rules for handling conflicts between inter-task and intra-task interactions. We also prove the correctness of our transformation, which preserves safety properties. I. INTRODUCTION A Time-Triggered (TT) system initiates all system activities-task activation, message transmission, and message detection-at predetermined points in time. Ideally, in a time-triggered operating system there is only one interrupt signal: the ticks generated by the local periodic clock. These statically defined activation instants enforce regularity and make TT systems more predictable than Event-Triggered (ET) systems. This approach is well-suited for hard real-time systems. In [1] and [2], Kopetz presents an approach for real-time system design based on the TT paradigm which comprises three essential elements: The global notion of time: It must be established by a periodic clock synchronization in order to enable a TT communication and computation, The temporal control structure of each task: In a sequence of computational or communication processes (called tasks), the start of a task is triggered by the progression of the global time, independently from the involved data of the task. The worst-case execution time and thus the worst-case termination instant are also assumed to be known a priori. These statically predefined start and worst-case termination instants, define the temporal control structure of the task

Design and Real-World Evaluation of Dependable Wireless Cyber-Physical Systems

The ongoing effort for an efficient, sustainable, and automated interaction between humans, machines, and our environment will make cyber-physical systems (CPS) an integral part of the industry and our daily lives. At their core, CPS integrate computing elements, communication networks, and physical processes that are monitored and controlled through sensors and actuators. New and innovative applications become possible by extending or replacing static and expensive cable-based communication infrastructures with wireless technology. The flexibility of wireless CPS is a key enabler for many envisioned scenarios, such as intelligent factories, smart farming, personalized healthcare systems, autonomous search and rescue, and smart cities. High dependability, efficiency, and adaptivity requirements complement the demand for wireless and low-cost solutions in such applications. For instance, industrial and medical systems should work reliably and predictably with performance guarantees, even if parts of the system fail. Because emerging CPS will feature mobile and battery-driven devices that can execute various tasks, the systems must also quickly adapt to frequently changing conditions. Moreover, as applications become ever more sophisticated, featuring compact embedded devices that are deployed densely and at scale, efficient designs are indispensable to achieve desired operational lifetimes and satisfy high bandwidth demands. Meeting these partly conflicting requirements, however, is challenging due to imperfections of wireless communication and resource constraints along several dimensions, for example, computing, memory, and power constraints of the devices. More precisely, frequent and correlated message losses paired with very limited bandwidth and varying delays for the message exchange significantly complicate the control design. In addition, since communication ranges are limited, messages must be relayed over multiple hops to cover larger distances, such as an entire factory. Although the resulting mesh networks are more robust against interference, efficient communication is a major challenge as wireless imperfections get amplified, and significant coordination effort is needed, especially if the networks are dynamic. CPS combine various research disciplines, which are often investigated in isolation, ignoring their complex interaction. However, to address this interaction and build trust in the proposed solutions, evaluating CPS using real physical systems and wireless networks paired with formal guarantees of a system’s end-to-end behavior is necessary. Existing works that take this step can only satisfy a few of the abovementioned requirements. Most notably, multi-hop communication has only been used to control slow physical processes while providing no guarantees. One of the reasons is that the current communication protocols are not suited for dynamic multi-hop networks. This thesis closes the gap between existing works and the diverse needs of emerging wireless CPS. The contributions address different research directions and are split into two parts. In the first part, we specifically address the shortcomings of existing communication protocols and make the following contributions to provide a solid networking foundation: • We present Mixer, a communication primitive for the reliable many-to-all message exchange in dynamic wireless multi-hop networks. Mixer runs on resource-constrained low-power embedded devices and combines synchronous transmissions and network coding for a highly scalable and topology-agnostic message exchange. As a result, it supports mobile nodes and can serve any possible traffic patterns, for example, to efficiently realize distributed control, as required by emerging CPS applications. • We present Butler, a lightweight and distributed synchronization mechanism with formally guaranteed correctness properties to improve the dependability of synchronous transmissions-based protocols. These protocols require precise time synchronization provided by a specific node. Upon failure of this node, the entire network cannot communicate. Butler removes this single point of failure by quickly synchronizing all nodes in the network without affecting the protocols’ performance. In the second part, we focus on the challenges of integrating communication and various control concepts using classical time-triggered and modern event-based approaches. Based on the design, implementation, and evaluation of the proposed solutions using real systems and networks, we make the following contributions, which in many ways push the boundaries of previous approaches: • We are the first to demonstrate and evaluate fast feedback control over low-power wireless multi-hop networks. Essential for this achievement is a novel co-design and integration of communication and control. Our wireless embedded platform tames the imperfections impairing control, for example, message loss and varying delays, and considers the resulting key properties in the control design. Furthermore, the careful orchestration of control and communication tasks enables real-time operation and makes our system amenable to an end-to-end analysis. Due to this, we can provably guarantee closed-loop stability for physical processes with linear time-invariant dynamics. • We propose control-guided communication, a novel co-design for distributed self-triggered control over wireless multi-hop networks. Self-triggered control can save energy by transmitting data only when needed. However, there are no solutions that bring those savings to multi-hop networks and that can reallocate freed-up resources, for example, to other agents. Our control system informs the communication system of its transmission demands ahead of time so that communication resources can be allocated accordingly. Thus, we can transfer the energy savings from the control to the communication side and achieve an end-to-end benefit. • We present a novel co-design of distributed control and wireless communication that resolves overload situations in which the communication demand exceeds the available bandwidth. As systems scale up, featuring more agents and higher bandwidth demands, the available bandwidth will be quickly exceeded, resulting in overload. While event-triggered control and self-triggered control approaches reduce the communication demand on average, they cannot prevent that potentially all agents want to communicate simultaneously. We address this limitation by dynamically allocating the available bandwidth to the agents with the highest need. Thus, we can formally prove that our co-design guarantees closed-loop stability for physical systems with stochastic linear time-invariant dynamics.:Abstract Acknowledgements List of Abbreviations List of Figures List of Tables 1 Introduction 1.1 Motivation 1.2 Application Requirements 1.3 Challenges 1.4 State of the Art 1.5 Contributions and Road Map 2 Mixer: Efficient Many-to-All Broadcast in Dynamic Wireless Mesh Networks 2.1 Introduction 2.2 Overview 2.3 Design 2.4 Implementation 2.5 Evaluation 2.6 Discussion 2.7 Related Work 3 Butler: Increasing the Availability of Low-Power Wireless Communication Protocols 3.1 Introduction 3.2 Motivation and Background 3.3 Design 3.4 Analysis 3.5 Implementation 3.6 Evaluation 3.7 Related Work 4 Feedback Control Goes Wireless: Guaranteed Stability over Low-Power Multi-Hop Networks 4.1 Introduction 4.2 Related Work 4.3 Problem Setting and Approach 4.4 Wireless Embedded System Design 4.5 Control Design and Analysis 4.6 Experimental Evaluation 4.A Control Details 5 Control-Guided Communication: Efficient Resource Arbitration and Allocation in Multi-Hop Wireless Control Systems 5.1 Introduction 5.2 Problem Setting 5.3 Co-Design Approach 5.4 Wireless Communication System Design 5.5 Self-Triggered Control Design 5.6 Experimental Evaluation 6 Scaling Beyond Bandwidth Limitations: Wireless Control With Stability Guarantees Under Overload 6.1 Introduction 6.2 Problem and Related Work 6.3 Overview of Co-Design Approach 6.4 Predictive Triggering and Control System 6.5 Adaptive Communication System 6.6 Integration and Stability Analysis 6.7 Testbed Experiments 6.A Proof of Theorem 4 6.B Usage of the Network Bandwidth for Control 7 Conclusion and Outlook 7.1 Contributions 7.2 Future Directions Bibliography List of Publication

uDDS: A Middleware for Real-time Wireless Embedded Systems

[EN] A Real-Time Wireless Distributed Embedded System (RTWDES) is formed by a large quantity of small devices with certain computing power, wireless communication and sensing/actuators capabilities. These types of networks have become popular as they have been developed for applications which can carry out a vast quantity of tasks, including home and building monitoring, object tracking, precision agriculture, military applications, disaster recovery, industry applications, among others. For this type of applications a middleware is used in software systems to bridge the gap between the application and the underlying operating system and networks. As a result, a middleware system can facilitate the development of applications and is designed to provide common services to the applications. The development of a middleware for sensor networks presents several challenges due to the limited computational resources and energy of the different nodes. This work is related with the design, implementation and test of a micro middleware for RTWDES; the proposal incorporates characteristics of a message oriented middleware thus allowing the applications to communicate by employing the publish/subscribe model. Experimental evaluation shows that the proposed middleware provides a stable and timely service to support different Quality of Service (QoS) levels. © 2011 Springer Science+Business Media B.V.This work was developed as a part of the D2ARS Project supported by CYTED. UNESCO code 120325;330417;120314;120305.González, A.; Mata, W.; Villaseñor, L.; Aquino, R.; Simó Ten, JE.; Chávez, M.; Crespo Lorente, A. (2011). uDDS: A Middleware for Real-time Wireless Embedded Systems. Journal of Intelligent and Robotic Systems. 64(3-4):489-503. https://doi.org/10.1007/s10846-011-9550-zS489503643-4Akyildiz, I.F., Su, W., Sankarasubramaniam, Y., Cayirci, E.: A survey on sensor networks. IEEE Commun. Mag. 40, 102–114 (2002)Aquino, R., González, A., Rangel, V., García, M. Villaseñor, L.A., Edwards-Block, A.: Wireless communication protocol based on EDF for wireless body sensor networks, k. Journal of Applied Sciences and Technology 6(2), 104–114 (2008)Bonnet, P., Gehrke, J.E., Seshadri, P.: Querying the physical world. IEEE Pers. Commun. 7(5), 10–15 (2000)Boonma, P., Suzuki, J.: TinyDDS: an interoperable and configurable publish/subscribe middleware for wireless sensor networks. In: Hinze, A., Buchmann, A. (eds.) Handbook of Research on Advanced Distributed Event-based Systems. Publish/Subscribe and Message Filtering Technologies, IGI Global (2009)Cerpa, A., Elson, J., Hamilton, M., Zhao, J.: Habitat monitoring: application driver for wireless communications technology. ACM SIGCOMM Workshop on Data Communications in Latin America and the Caribbean, Costa Rica (2002)Corsaro, A., Schmidt, D.C.: The design and performace of real-time java middleware. IEEE Trans. Parallel Distrib. Syst. 14(11), issn 1045–9219, 1155–1167 (2003)Culler, D.E., Hong, W.: Wireless sensor networks introduction. Commun. ACM 47(6), 30–33 (2004)Estrin, D., Govindan, R., Heidemann, J.S., Kumar, S.: Next century challenges: scalable coordination in sensor networks. In: Mobile Computing and Networking, pp. 263–270 (1999)Heinzelman, W.B., Murphy, A.L., Carvalho, H.S.: Middleware to support sensor network applications. IEEE Netw. 18, 6–14 (2004)Hill, J., Szewczyk, R., Woo, A., Hollar, S., Culler, D., Pister, K.: System architecture directions for networked sensors. ACM SIGOPS Oper. Syst. Rev. 34(5), 93–104 (2000)Levis, P., Culler, D.: Mate: a tiny virtual machine for sensor networks. In: Proceedings of the 10th International Conference on Achitectural Support for Programming Languages and Operating Systems. San Jose, CA (2002)Liu, T., Martonosi, M.: Impala: a middleware system for managing autonomic, parallel sensor systems. In: Proceedings of the Ninth ACM SIGPLAN Symposium on Principles and Practice of Parallel Programming. San Diego, CA (2003)Mata, W., González, A., Aquino, R., Crespo, A., Ripoll, I., Capel, M.: A wireless networked embedded sistem with a new real-time Kernel PaRTiKle. Electronics, Robotics and Automotive Mechanics Conference, CERMA 2007. ISBN 0-7695-2974-7. Cuernavaca, México (2007)Mata, W., González, A., Crespo, A.: A proposal for real-time middleware for wireless sensor networks. Workshop on Sensor Networks and Applications (WseNA’08). Gramado, Brasil (2008)Mata, W., González, A., Fuentes, G., Fuentes, R., Crespo, A., Carr, D.: Porting jRate(RT-Java) to a POSIX real-time Linux Kernel. Tenth Real-Time Linux Workshop. Colotlán, Jalisco México (2008)MiLAN Project: Available: http://www.futurehealth.rochester.edu/milan (2008)OMG, Data Distribution Service for Real-Time Systems Version 1.2. OMG Technical Document (2007)OMG, Model Driven Architecture (MDA), Document Number ormsc/2001-07-01. Technical report, OMG (2001)OMG, Overview and guide to OMGs architecture, OMG Technical Document formal/03-06-01 (2003)Pardo-Castellote, G., Farabaugh, B., Warren, R.: An Introduction to DDS and Data-centric Communications. Available: http://www.omg.org/news/whitepapers/Intro_To_DDS.pdf (2005)Peiro, S., Masmano, M., Ripoll, I., Crespo, A.: PaRTiKle OS, a replacement of the core of RTLinux. In: 9th Real-Time Linux Workshop (2007)Peiro, S., Masmano, M., Ripoll, I., Crespo, A.: PaRTiKle LPC, port to the LPC2000. Tehth Real-Time Linux Workshop. Colotlán, Jalisco M’exico (2008)Pottie, G.J., Kaiser, W.J.: Wireless integrated networks sensors. Commun. ACM 43(5), 52–58 (2000)Souto, E., Guimaraes, G., Vasconcelos, G., Vieira, M., Rosa, N., Ferraz, C., Kelner, J.: Mires: a publish/subscribe middleware for sensor networks. Pers Ubiquit Comput 10(1), 37–44 (2006)St Ville, L., Dickman, P.: Garnet: a middleware architecture for distributing data streams originating in wireless sensor networks. In: Proceedings. 23rd International Conference on Distributed Computing Systems Workshops (2003