Middleware Services Research Articles

Knowledge-Aware and Service-Oriented Middleware for deploying pervasive services

Many applications and services have emerged in the frame of new Internet of Things paradigm. This novel view has opened the Web services to a variety of devices especially to tiny and resource-constrained devices. Wireless Sensor and Actuator Networks belong to that kind of devices. Those networks have become one of the more promising technologies to take part in the Future Internet. However, the integration of Sensor and Actuator Networks into the Service Cloud is a hard challenge requiring specific new architectures and protocols. This paper presents a middleware approach addressing this important issue. A Knowledge-Aware and Service-Oriented Middleware (KASOM) for pervasive embedded networks is proposed. The major aim of KASOM is to offer advanced and enriched pervasive services to everyone connected to Internet. In this sense, KASOM implements mechanisms and protocols which allow managing the knowledge generated in pervasive embedded networks in order to expose it to Internet users in a readable way. General functional requirements of embedded sensor and actuator platforms have been taken into account when designing KASOM, with special attention in energy consumption, memory and bandwidth. The KASOM evaluation and validation will be demonstrated through a real Wireless Sensor and Actuator Network deployment based on integral healthcare services in a sanatorium.

10.2.1 An Investigation on the Applicability of DDS Middleware as a Systems Integration Tool

AbstractThis paper describes an investigation of the emerging Object Management Group's (OMG) Distributed Data Services (DDS) middleware as an open “infrastructure” solution, and proposes a DDS‐based “Vertical” systems integration approach to address system integration of complex systems. The paper commences with an introduction to the DDS middleware, which is intended to be the underlining communication framework for real‐time distributed mission critical systems. The paper then describes the proposed “vertical” systems integration approach and where it fits into the systems engineering lifecycle in the Australian defence context. The investigation extends to include a case study using an in‐house Systems Integration Sandpit (SIS) – Robotic Surveillance System. The case study aims to investigate the ease and efficiency of integrating the existing communication framework of the selected system into a DDS‐based communication architecture. The paper further discusses lessons learned and insights captured during the conduct of the study, and outlines further research and development.

Service-oriented middleware for the Future Internet: state of the art and research directions

Abstract Service-oriented computing is now acknowledged as a central paradigm for Internet computing, supported by tremendous research and technology development over the last 10 years. However, the evolution of the Internet, and in particular, the latest Future Internet vision, challenges the paradigm. Indeed, service-oriented computing has to face the ultra large scale and heterogeneity of the Future Internet, which are orders of magnitude higher than those of today’s service-oriented systems. This article aims at contributing to this objective by identifying the key research directions to be followed in light of the latest state of the art. This article more specifically focuses on research challenges for service-oriented middleware design, therefore, investigating service description, discovery, access, and composition in the Future Internet of services.

Bringing pervasive embedded networks to the service cloud: A lightweight middleware approach

The emergence of novel pervasive networks that consist of tiny embedded nodes have reduced the gap between real and virtual worlds. This paradigm has opened the Service Cloud to a variety of wireless devices especially those with sensorial and actuating capabilities. Those pervasive networks contribute to build new context-aware applications that interpret the state of the physical world at real-time. However, traditional Service-Oriented Architectures (SOA), which are widely used in the current Internet are unsuitable for such resource-constraint devices since they are too heavy. In this research paper, an internetworking approach is proposed in order to address that important issue. The main part of our proposal is the Knowledge-Aware and Service-Oriented (KASO) Middleware that has been designed for pervasive embedded networks. KASO Middleware implements a diversity of mechanisms, services and protocols which enable developers and business processing designers to deploy, expose, discover, compose, and orchestrate real-world services (i.e. services running on sensor/actuator devices). Moreover, KASO Middleware implements endpoints to offer those services to the Cloud in a REST manner. Our internetworking approach has been validated through a real healthcare telemonitoring system deployed in a sanatorium. The validation tests show that KASO Middleware successfully brings pervasive embedded networks to the Service Cloud.

Bloom filter-based discovery protocol for DDS middleware

The Data Distribution Service (DDS) middleware has recently been standardized by the OMG. Prior to data communication, a discovery protocol had to locate and obtain remote DDS entities and their attributes. Specifically, DDS discovery matches the DataWriters (DWs) and DataReaders (DRs) entities ( Endpoints) situated in different network nodes. DDS specification does not specify how this discovery is translated “into the wire”. To provide interoperability and transparency between different DDS implementations, the OMG has standardized the DDS Interoperability Wire Protocol (DDS-RTPS). Any compliant DDS-RTPS implementation must support at least the SDP (Simple Discovery Protocol). The SDP works in relatively small or medium networks but it may not scale as the number of DDS Endpoints increases. This paper addresses the design and evaluation of an SDP alternative–which uses Bloom Filters (BF)–that increases DDS scalability. BFs use Hash functions for space-efficient probabilistic data set representation. We provide both analytical and experimental studies. Results show that our approach can improve the discovery process (in terms of network load and node resource consumption), especially in those scenarios with large Endpoint per Participant ratios.

Recent Advances in Mobile Middleware for Wireless Systems and Services

The most visible technology advance in the last decade is arguably the popular uses of wireless mobile handsets such as cellular phones. These devices are not just for phone calls, but also for the Internet access and management of mobile data. Many of them are equipped with positioning systems such as GPS, creating significant commercial opportunities for a range of new applications such as location-based services. Indeed, despite the recent economic downturn, the mobile computing industry continues to boom. A crucial technological challenge to develop applications for wireless mobile handsets is to deal with their heterogeneity. There are a large number of models running different operating systems. They come with vastly different capabilities in terms of computing power and applications they can support, and unlike traditional computers such as desktops and laptops, many times the software development kits are manufacturer-specific or even model-specific. Targeting at different consumer groups, they are also designed with different considerations on key components such as wireless interfaces, screen size, with or without keyboard/accelerometer/GPS, and so on. Developing novel mobile middleware solutions appears to be a natural strategy to circumvent the heterogeneity problem. By allowing application developers to concentrate their efforts on application logic, without taking into account the device-specific issues, the development and deployment of applications over heterogeneous mobile devices can be greatly accelerated and simplified. It is motivated by this belief that in 2008 the International Conference on MOBILe Wireless MiddleWARE, Operating Systems, and Applications (Mobilware) was launched with the specific goal to identify, propose, validate, and spread the adoption of open and interoperable software-support solutions, specifically designed and implemented for wireless mobile handsets. The past 2008 and 2009 editions of Mobilware were highly successful, attracting a large number of high-quality technical submissions from both academic and industrial communities. Mobilware’10 follows this success with a technical program that covers a wide range of hot issues in research and practitioning of mobile middleware technologies. Some papers address network, systems, and service management issues in dependence of location and context. Some contributions relate to middleware interface management, architectures, and security. A considerable part of the program is devoted to new applications for mobile services, such as multimedia, wireless sensor and vehicular network applications, and surveillance systems. This special section of MONET is organized with the extended versions of the papers selected from the best P. Bellavista University of Bologna, Bologna, Italy

A survey on service-oriented middleware for wireless sensor networks

Wireless sensor networks (WSN) are used for many applications such as environmental monitoring, infrastructure security, healthcare applications, and traffic control. The design and development of such applications must address many challenges dictated by WSN characteristics on one hand and the targeted applications on the other. One of the emerging approaches used for relaxing these challenges is using service-oriented middleware (SOM). Service-oriented computing, in general, aims to make services available and easily accessible through standardized models and protocols without having to worry about the underlying infrastructures, development models, or implementation details. SOM could play an important role in facilitating the design, development, and implementation of service-oriented systems. This will help achieve interoperability, loose coupling, and heterogeneity support. Furthermore, SOM approaches will provision non-functional requirements like scalability, reliability, flexibility, and Quality of Service (QoS) assurance. This paper surveys the current work in SOM and the trends and challenges to be addressed when designing and developing these solutions for WSN.

Design and implementation of CLASS: A Cross-Layer ASSociation scheme for wireless mesh networks

This paper focuses on the design and implementation of CLASS, a Cross-Layer Association scheme for IEEE 802.11-based multi-hop wireless mesh networks. The widely-used association strategy in traditional IEEE 802.11 wireless LANs allows a Mobile Station (MS) to scan wireless access links and then associate with the Access Point (AP) that has the best Received Signal Strength Indication (RSSI) value. Unlike traditional wireless LANs, IEEE 802.11-based wireless mesh networks consist of a multi-hop wireless backhaul. As such, the performance experienced by an MS after association with a specific Mesh Access Point (MAP) depends heavily on the conditions of both the access link (e.g., traffic load of associated stations, the frame error rate between an MS and an MAP) and the mesh backhaul (e.g., end-to-end latency and asymmetric uplink/downlink transportation costs). That is, selecting the MAP that yields the “best” performance depends on several factors and cannot be determined solely on the RSSI of the MS-MAP access link. CLASS uses an end-to-end airtime cost metric to determine the MAP to which an MS should associate. The airtime cost metric is based on the IEEE 802.11s, and comprises the access link airtime cost and the backhaul airtime cost. The proposed association scheme considers the frame error rate for various packet sizes, the available bandwidth on the access link after the association of the new MS, and the asymmetric uplink and downlink transportation costs on the backhaul. All experimental results are based on actual Linux-base testbed implementation. We also implement a general Cross-Layer Service Middleware (CLSM) module that is used to monitor network conditions and gather relevant metrics and factor values. Experimental results show that the proposed association scheme is able to identify the MAP which yields the highest end-to-end network performance for the mobile stations after their associations.

A Generic Component-Based Approach for Programming, Composing and Tuning Sensor Software

Wireless sensor networks (WSNs) are being extensively deployed today in various monitoring and control applications by enabling rapid deployments at low cost and with high flexibility. However, high-level software development is still one of the major challenges to wide-spread WSN adoption. The success of high-level programming approaches in WSNs is heavily dependent on factors such as ease of programming, code well-structuring, degree of code reusability, required software development effort and the ability to tune the sensor software for a particular application. Component-based programming has been recognized as an effective approach to satisfy such requirements. However, most of the componentization efforts in WSNs were ineffective due to various reasons, such as high resource demand or limited scope of use. In this article, we present Remora, a novel component-based approach to overcome the hurdles of WSN software implementation and configuration. Remora offers a well-structured programming paradigm that fits very well with resource limitations of embedded systems, including WSNs. Furthermore, the special attention to event handling in Remora makes our proposal more practical for embedded applications, which are inherently event-driven. More importantly, the mutualism between Remora and underlying system software promises a new direction towards separation of concerns in WSNs. This feature also offers a practical way to develop sensor middleware services which should be generic and developed close to the operating system. Additionally, it allows the customization of sensor software—deploying only application-required system-level services on nodes, instead of installing a fixed large system software image for any application. Our evaluation results show that the deployed Remora applications have an acceptable memory overhead and a negligible CPU cost compared with the state-of-the-art development models.

Simulation-based analysis of middleware service impact on system reliability: Experiment on Java application server

Being a popular runtime infrastructure in the era of Internet, middleware provides more and more services to support the development, deployment and management of distributed systems. At the same time, the reliability of middleware services has a significant impact on the overall reliability of the system. Different services have different impacts and different service fault-tolerance solutions have different costs and risks. Therefore, the identification of the services that greatly affect the whole system reliability is the major obstacle to achieving reliable middleware-based systems. In this paper, we present an analytical framework to automatically reason and quantify such impacts when deploying the target system. In this framework, faults are represented by exceptions in modern programming languages; service failures are simulated by software fault injection; reliability impacts are measured by scenarios. This framework is demonstrated on multiple JEE application servers, including JBoss, JonAS and PKUAS. The experiments on two JEE blueprint applications, namely JPS and ECperf, show the feasibility, the applicability and the usability of this framework.

Sim-PETEK: A Parallel Simulation Execution Framework for Grid Environments

In this paper we introduce a framework for parallel and distributed execution of simulations (Sim-PETEK), a middleware for minimizing the total run time of batch runs and Monte Carlo trials. Sim-PETEK proposes a generic solution for applications in the simulation domain, which improves on our previous work done to parallelize simulation runs in a single node, multiple central processing unit (CPU) setting. Our new framework aims at managing a heterogeneous computational resource pool consisting of multiple CPU nodes distributed on a potentially geographically dispersed network, through a service-oriented middleware layer that is compliant to Web Services Resource Framework standard, thereby providing a scalable and flexible architecture for simulation software developers. What differentiates Sim-PETEK from a general-purpose, Grid-based job-distribution middleware is a number of simulation-specific aspects regarding the specification, distribution, monitoring, result collection and aggregation of simulation runs. These aspects are prevalent in the structure of the messages and in the protocol of interaction both among the constituent services of the framework and within the interfaces exposed to the external clients.

Advanced Sensor Network Software Deployment using Application-level Quality Goals

If we are to deploy sensor applications in a realistic business context, we must provide innovative middleware services to control and enforce required system behavior. Sensor application developers typically reason about required system behavior in terms of high-level quality goals. Due to the extreme dynamism, scale and unreliability of wireless sensor networks, managing these goals using contemporary software management techniques without support for high-level quality goals quickly becomes challenging. This paper presents QARI, a middleware service which addresses these management challenges by offering a simple yet flexible way to define, enforce, and maintain high-level quality goals for software deployment in wireless sensor networks. We have evaluated QARI using the LooCI component model on two sensor node platforms; results confirm that QARI enables quality aware software deployment for a single application as well as multiple applications, and even in the presence of node failure and mobility.

A novel statistical time-series pattern based interval forecasting strategy for activity durations in workflow systems

Forecasting workflow activity durations is of great importance to support satisfactory QoS in workflow systems. Traditionally, a workflow system is often designed to facilitate the process automation in a specific application domain where activities are of the similar nature. Hence, a particular forecasting strategy is employed by a workflow system and applied uniformly to all its workflow activities. However, with newly emerging requirement to serve as a type of middleware services for high performance computing infrastructures such as grid and cloud computing, more and more workflow systems are designed to be general purpose to support workflow applications from many different domains. Due to such a problem, the forecasting strategies in workflow systems must adapt to different workflow applications which are normally executed repeatedly such as data/computation intensive scientific applications (mainly with long-duration activities) and instance intensive business applications (mainly with short-duration activities). In this paper, with a systematic analysis of the above issues, we propose a novel statistical time-series pattern based interval forecasting strategy which has two different versions, a complex version for long-duration activities and a simple version for short-duration activities. The strategy consists of four major functional components: duration series building, duration pattern recognition, duration pattern matching and duration interval forecasting. Specifically, a novel hybrid non-linear time-series segmentation algorithm is designed to facilitate the discovery of duration-series patterns. The experimental results on real world examples and simulated test cases demonstrate the excellent performance of our strategy in the forecasting of activity duration intervals for both long-duration and short-duration activities in comparison to some representative time-series forecasting strategies in traditional workflow systems.

Koko: an architecture for affect-aware games

The importance of affect in delivering engaging experiences in entertainment and educational games is well recognized. Yet, current techniques for building affect-aware games are limited, with the maintenance and use of affect in essence being handcrafted for each game. The Koko architecture describes a service-oriented middleware that reduces the burden of incorporating affect recognition into games, thereby enabling developers to concentrate on the functional and creative aspects of their applications. The Koko architecture makes three key contributions: (1) improving developer productivity by creating a reusable and extensible environment; (2) yielding an enhanced user experience by enabling independently developed games and other applications to collaborate and provide a more coherent user experience than currently possible; (3) enabling affective communication in multiplayer and social games. Further, Koko is intended to be used as an extension of existing game architectures. We recognize that complex games require additional third party libraries, such as game engines. To enable the required flexibility we define the interfaces of the Koko architecture in a formal manner, thereby enabling the implementation of those interfaces to readily adapt to the unique requirements of game's other architectural components and requirements.

The Design and Implementation of Tile Map Service

In order to upgrade the WebGIS legacy systems smoothly, and improve the response speed of traditional WebGIS and user experience, this paper designs and develops a tile map service based on middleware technology. Through systematic analysis of its basic principle and system architecture, this paper gives several optimization strategies. Finally, we make a performance comparison between tile map service middleware and traditional OGC (Open Geospatial Consortium, OGC) standard WMS service. Our experimental results show that the average response time of tile map service reduced by 46% than sending WMS request to WMS server directly, and the TMS middleware has a high efficiency when cutting map tiles dynamically because of its meta-tiling strategy. The study shows that tile map service middleware has important application value both in improving traditional WebGIS performance and in upgrading existing legacy systems.

유비쿼터스 센서 네트워크 환경에서 온톨로지와 규칙을 이용한 지능형 서비스 미들웨어

USN 미들웨어에 대한 몇몇 연구가 이미 존재하지만 아직까지 미들웨어 표준이 정의되지는 않은 상태이므로 어떠한 미들웨어가 가장 효과적일지는 알 수 없다. 특별히 본 논문에서는 미들웨어의 많은 기능들 가운데 센서 네트워크 환경에서 지능형 서비스를 제공하는 것을 목표로 한다. 센서를 기반으로 하는 많은 응용들은 단순히 센서의 값을 취하거나 모니터링 하기 위해서센서를 사용하기보다는이를기반으로 상황을인지하고 지능형서비스를 제공하기를 원한다. 그러나 현재 센서 네트워크 미들웨어 수준에서 지능형 서비스를 지원하기 위한 필요성은 인식하고 있으나, 구체적으로 어떻게 지능형 서비스를 제공할 것 인지에 대한 연구는 찾아보기 힘들다. 그러므로 본 논문에서는 범용의 USN 미들웨어에서 지능형 서비스를 지원하기 위한 컴포넌트를 설계하고 구체적인 서비스지원 방법을 제안한다. 이러한 목적을 위하여 본 논문에서는USN 미들웨어 응용에서 제공하는 서비스와 센서 네트워크를 정의하고 두 개념들을 연계하기 위해서 센서-서비스 온톨로지를 제안한다. 센서-서비스 온톨로지는 저수준의 정보로부터 고수준의 정보를 추론하기 위하여 사용된다. 또한 응용의 상황 정보를 추론에 반영하기 위하여 규칙을 이용한 추론방법을 제안한다. 논문은 제안한 지능형 서비스 미들웨어는 프로토타입을 구현하고 성능평가를 통하여 다양한 응용을 위해서 사용될 수 있음을 보인다. There are some of the studies on sensor middleware. However the standard middleware has not yet been defined. Especially, this paper focuses on the processing an intelligent service of the main functions of middleware. Several applications in the sensor network environment support not only monitoring services, but also sensor-based context-awareness and intelligent services based on sensors. However, the previous studies about USN middleware only mentioned the need for intelligent service and did not discuss the architecture and method for supporting the intelligent service in detail. Therefore this paper designs a USN middleware for providing intelligent services and proposes the method for processing the services. For this purpose, this paper proposes the Sensor-Service ontology to define the concept of services and sensors for USN applications and the relationship between them. The Sensor-Service ontology is used to infer high-level information from low-level information. To apply a variety of environmental context to intelligent services, the paper uses the rule-based reasoning. This paper implements the proposed intelligent service middleware as a prototype and then shows that the middleware can be used for a variety of USN applications through the performance evaluation.

Supporting the Ubiquitous Doctor

In health service environments, support to mobility is an important issue, given that the mobility of the medical professionals is inherent to the organizational structure of healthcare entities, such as hospitals and medical centers. The concept of the “Ubiquitous Doctor” refers to a doctor that works anytime, anywhere and uses any computer device. For doing this, the doctor needs support to migrate a work session started on a device to another one, either for convenience (more comfort) or forced (e.g. low battery). This so called ‘session migration’ presents some challenges like preventing from disruption and performing quickly, so the Ubiquitous Doctor’s productivity can be improved. This chapter presents the design and implementation of a contextaware system (middleware services and application) to support the Ubiquitous Doctor, as well as experiments that show that the average migration time represents a low impact on the transition time between medical activities, and an assessment carried out with a group of doctors confirmed the importance of supporting the migration process in order to make it fast and reliable. The doctors also agreed on the importance of using the most convenient device based on context variables like user status and location.

Online Diarization of Streaming Audio-Visual Data for Smart Environments

For an environment to be perceived as being smart, contextual information has to be gathered to adapt the system's behavior and its interface towards the user. Being a rich source of context information speech can be acquired unobtrusively by microphone arrays and then processed to extract information about the user and his environment. In this paper, a system for joint temporal segmentation, speaker localization, and identification is presented, which is supported by face identification from video data obtained from a steerable camera. Special attention is paid to latency aspects and online processing capabilities, as they are important for the application under investigation, namely ambient communication. It describes the vision of terminal-less, session-less and multi-modal telecommunication with remote partners, where the user can move freely within his home while the communication follows him. The speaker diarization serves as a context source, which has been integrated in a service-oriented middleware architecture and provided to the application to select the most appropriate I/O device and to steer the camera towards the speaker during ambient communication.

Quality of Service on Grid: architectural and methodological issues

AbstractThe rapid evolution of Grid Computing and the development of new middleware services make Grid platforms increasingly used not only for best effort scientific jobs but also in industrial and business applications. This has taken to the growing demand of Quality of Service (QoS) support. However, the QoS issue on Grid is quite difficult, as Grid has been originally designed without any QoS support, and it is a complex system. During the previous years some solutions have been proposed to supply QoS for specific classes of applications. This results in a focused and a heterogeneous approach, so that it is hard to evaluate its sufficiency and its robustness with respect to the large spectrum of possible Grid applications. In this context, our contribution concerns three points: first, we analyze the current approach to QoS on Grid as a relationship among QoS features, applications, and architectures; second, we evaluate the QoS requirements of two recent QoS‐demanding applications on Grid, namely Massive Multiplayer Online Games and Urgent Computing, comparing these requirements with the support provided by current QoS architectures; and third, we propose an alternative approach to QoS provision on Grid based on the definition of a dedicated QoS‐management layer to overcome the limitations of the current methodologies. Copyright © 2010 John Wiley & Sons, Ltd.

Quality of security adaptation in parallel disk systems

In the past decade, parallel disk systems have been highly scalable and able to alleviate the problem of disk I/O bottleneck, thereby being widely used to support data-intensive applications. Although a variety of parallel disk systems were developed, most existing disk systems lack a means to adaptively control the quality of security for dynamically changing workloads. We address this gap in disk technology by designing, implementing, and evaluating a quality of security control framework for parallel disk systems, or ASPAD for short, that makes it possible for parallel disk systems to adapt to changing security requirements and workload conditions. The ASPAD framework comprises four major components, namely, a security service middleware, a dynamic data-partitioning mechanism, a response time estimator, and an adaptive security quality controller. The framework is conducive to adaptively and expeditiously determining security services for requests submitted to a parallel disk system in a way to improve security of the disk system while making an effort to guarantee desired response times of the requests. We conduct extensive experiments to quantitatively evaluate the performance of the proposed ASPAD framework. Empirical results show that ASPAD significantly improves the overall performance of parallel disk systems over the same disk systems without using the ASPAD framework.