Context-aware RAON middleware for opportunistic network

Application development and deployment on Mobile Ad Hoc Networks (MANET) is a major challenge in the widespread use of MANET. The increasing D2D communication in 5G networks has renewed interest in an effective middleware design for MANET where application developers face various challenges such as unstable connectivity, high error rate, mobility induced disruption and disconnection, and limited battery power. We find that unstructured overlay network provides a good abstraction to facilitate application development and deployment on MANET. In this paper, we present the design of a middleware that builds a Resource-Aware Overlay Network (RAON), which is an unstructured overlay network of nodes engaged in the application that employs a query–reply mechanism for resource discovery. RAON is enhanced with features such as proactive neighbor replacement, congestion-aware data download and cooperative caching. Simulation results show that these features are effective in reducing query delay, improving data availability, and balancing node power consumption with protocol performance. We also present the middleware software design that offers the API based on node and path abstractions to applications. The middleware implements a generic context framework for acquiring device and user context. We discuss the implementation of application-level multicast and credit-based file-sharing applications using the middleware API. The middleware is implemented in Java J2ME on Android, which is tested in an ad hoc network of Nexus 7 devices running OLSR.     

Intelligent service processing in common USN middleware

The Ubiquitous sensor network (USN) is composed of several heterogeneous sensors with a variety of characteristics. An application based on the sensor network also has various requirements to provide services to users. Therefore it is important to develop the common USN middleware for flexible integration between the sensor networks and applications. Especially, this paper focuses on intelligent service management which is one of the main functions of USN middleware. Several applications in the sensor network environment support not only monitoring services, but also sensor-based context-awareness and intelligent services. In many applications, however, approaches to support intelligent services depend on the application because the standard method has been undefined yet. Therefore this paper proposes a common method for processing intelligent services in USN middleware independent of an application. The proposed method is implemented and evaluated as a component of USN middleware.     

EgoSpaces: facilitating rapid development of context-aware mobile applications

Today's mobile applications require constant adaptation to their changing environments, or contexts. Technological advances have increased the pervasiveness of mobile computing devices such as laptops, handhelds, and embedded sensors. The sheer amount of context information available for adaptation places a heightened burden on application developers as they must manage and utilize vast amounts of data from diverse sources. Facilitating programming in this data-rich environment requires a middleware that provides context information to applications in an abstract form. In this paper, we demonstrate the feasibility of such a middleware that allows programmers to focus on high-level interactions among programs and to employ declarative abstract context specifications in settings that exhibit transient interactions with opportunistically encountered components. We also discuss the novel context-aware abstractions the middleware provides and the programming knowledge necessary to write applications using it. Finally, we provide examples demonstrating the infrastructure's ability to support differing tasks from a wide variety of application domains.     

MobiPADS: a reflective middleware for context-aware mobile computing

Traditionally, middleware technologies, such as CORBA, Java RMI, and Microsoft's DCOM, have provided a set of distributed computing services that essentially abstract the underlying network services to a monolithic "black box." In a mobile operating environment, the fundamental assumption of middleware abstracting a unified distributed service for all types of applications operating over a static network infrastructure is no longer valid. In particular, mobile applications are not able to leverage the benefits of adaptive computing to optimize its computation based on current contextual situations. In this paper, we introduce the Mobile Platform for Actively Deployable Service (MobiPADS) system. MobiPADS is designed to support context-aware processing by providing an executing platform to enable active service deployment and reconfiguration of the service composition in response to environments of varying contexts. Unlike most mobile middleware, MobiPADS supports dynamic adaptation at both the middleware and application layers to provide flexible configuration of resources to optimize the operations of mobile applications. Within the MobiPADS system, services (known as mobilets) are configured as chained service objects to provide augmented services to the underlying mobile applications so as to alleviate the adverse conditions of a wireless environment.     

A comprehensive solution for application‐level adaptation

Driven by the emergence of mobile and pervasive computing there is a growing demand for context‐aware software systems that can dynamically adapt to their run‐time environment. We present the results of project MADAM that has delivered a comprehensive solution for the development and operation of context‐aware, self‐adaptive applications. The main contributions of MADAM are (a) a sophisticated middleware that supports the dynamic adaptation of component‐based applications, and (b) an innovative model‐driven development methodology that is based on abstract adaptation models and corresponding model‐to‐code transformations. MADAM has demonstrated the viability of a general, integrated approach to application‐level adaptation. We discuss our experiences with two real‐world case studies that were built using the MADAM approach. Copyright © 2008 John Wiley & Sons, Ltd.     

Combining heterogeneous service technologies for building an Internet of Things middleware

Radio-frequency identification (RFID) is a technology that allows ordinary objects to be uniquely identified by “smart tags” which are also capable of storing small quantities of data. The term Internet of Things was originated from a vision strongly coupled with supply-chain concerns and RFID tagged objects. However the idea of such Internet of Things has evolved in a wider sense, referring now to a ubiquitous object society combining RFID, sensor networks and pervasive computing technologies. This scenario involves different requirements such as heterogeneity and dynamicity of objects, sensors, applications and protocols as well as the need for allowing the dynamic evolution of such applications. These issues seemed to be easily addressed if the principles of service-oriented computing (SOC), like loose coupling and heterogeneity, are used for constructing such architectures and applications. In this paper we underline what benefits SOC can offer to constructing a middleware for the Internet of Things. These concepts have been applied in a service-oriented middleware that tries to leverage the existing Internet of Things architectural concepts by using SOC principles in order to bring more flexibility and dynamicity. We describe the approaches used in that middleware and the lessons learned from that experience. This middleware was initially tested on an application for tracking and monitoring supply-chain objects, and later extended to target wider application domains that are also described in this paper. The project described here has become part of the OW2 AspireRFID open-source project.     

Utilizing architectural styles to enhance the adaptation support of middleware platforms

ContextModern middleware platforms provide the applications deployed on top of them with facilities for their adaptation. However, the level of adaptation support provided by the state-of-the-art middleware solutions is often limited to dynamically loading and off-loading of software components. Therefore, it is left to the application developers to handle the details of change such that the system’s consistency is not jeopardized.ObjectiveWe aim to change the status quo by providing the middleware facilities necessary to ensure the consistency of software after adaptation. We would like these facilities to be reusable across different applications, such that the middleware can streamline the process of achieving safe adaptation.MethodOur approach addresses the current shortcomings by utilizing the information encoded in a software system’s architectural style. This information drives the development of reusable adaptation patterns. The patterns specify both the exact sequence of changes and the time at which those changes need to occur. We use the patterns to provide advanced adaptation support on top of an existing architectural middleware platform.ResultsOur experience shows the feasibility of deriving detailed adaptation patterns for several architectural styles. Applying the middleware to adapt two real-world software systems shows the approach is effective in consistently adapting these systems without jeopardizing their consistency.ConclusionWe conclude the approach is effective in alleviating the application developers from the responsibility of managing the adaptation process at the application-level. Moreover, we believe this study provides the foundation for changing the way adaptation support is realized in middleware solutions.     

An approach to enhance the efficiency of opportunistic grids

Opportunistic grid computing middleware has as a main concern the need to preserve the performance of the local applications running on machines that donate resources to the grid. This concern, together with the fact that it happens in an extremely dynamic environment, causes the adoption of a treatment based on thetextitbest‐effort principle for grid applications. This means that efficient application management schemes are usually not employed, which results in less than optimal performance as grid applications often need to be restarted due to (often temporary) resource claims by local user applications. This paper presents a method to improve the performance of grid applications, taking into account resource usage profiles for local applications, trying to identify when such resource claims are temporary and avoiding costly actions such as the migration of grid tasks. The approach is proposed as an extension to the InteGrade middleware and its evaluation shows promising results for the efficient management of grid applications. Copyright © 2011 John Wiley & Sons, Ltd.     

Integrated Development of Context-Aware Applications in Smart Spaces

When designing context-aware applications for smart spaces, developers must provide interface specifications for perceptual components, which often come from multiple vendors. The authors outline a set of structuring principles that leverage such specifications. IBM has introduced two tools that facilitate the development of smart space applications. Chilix is a middleware library for bridging disaggregated systems, and SitCom is an integrated development environment enabling context modeling, and simulation and lifecycle management of perceptual components. Chilix provides an attractive lightweight alternative to legacy middleware for distributed computing. SitCom supports perceptual component developers, service developers and context-modeling experts across the development life cycle.     

基于协议无感知转发技术的信息中心网络：设计、实现与应用

软件定义网络(SDN)的核心思想是将网络中控制平面和数据平面进行解耦,采用集中控制的方式给用户提供开放可编程的接口。信息中心网络(ICN)则集中在对内容进行命名和基于内容名字的路由。协议无感知转发(POF)是一种支持自定义协议的SDN转发技术。随着未来网络技术的研究与发展,基于SDN思想来实现ICN则可能成为一种解决方案,因而提出了一种基于POF技术的ICN网络设计方案与实现,并搭建了基于POF技术的ICN实验床。多人视频会议应用表明,该设计方案的正确性与可行性,不仅能转发ICN数据包,还能很好地实现实时性应用。     

Annealed embeddings of communication patterns in an interconnectioncached network

The communication needs of many parallel applications exhibit what we call switching locality. In such applications, each computation entity (process, thread, etc.) tends to restrict its communication to a small set of other entities. The physical location or proximity of these entities can be arbitrary, as long as the communication degree is small. The Interconnection Cached Network (ICN) is a reconfigurable network ideally suited for exploiting such locality. The use of fast small crossbar switches (Interconnection Caches) with a larger, but slower, reconfigurable network (optimized for connectivity) lets the ICN adapt to the communication requirements of individual applications, potentially achieving higher performance. Embedding communication patterns efficiently in an ICN, requires finding a bounded l-contraction of the underlying communication graph. The problem of identifying whether a graph has a bounded and l-contraction for a given integer l is known to be NP-complete for l>2. We describe a heuristic algorithm based on simulated annealing for this problem. We test the effectiveness of our approach by using it to embed graphs, representing regular communication patterns, for which the best solutions are deterministically known. The algorithm does not rely on any structural information of the communication pattern and is therefore applicable to irregular patterns as well. The results of applying our heuristics to embed such irregular graphs are also presented     

Seamless User-Level Handoff in Ubiquitous Multimedia Service Delivery

Advancing mobile computing technologies are enabling ubiquitous personal computing environment. In this paper, we focus on an important problem in such environment: user mobility. In the case of user mobility, a user is free to access his/her personalized service at anytime, anywhere, through any possible mobile/fixed devices. Providing mobility support in this scenario poses a series of challenges. The most essential problem is to preserve the user's access to the same service despite changes of the accessing host or service provider. Existing system-level mobility solutions are insufficient to address this issue since it is not aware of the application semantics. On the other hand, making each application to be mobility-aware will greatly increase the development overhead. We argue that the middleware layer is the best place to address this problem. On one hand, it is aware of application semantics. On the other hand, by building application-neutral mobility functions in the middleware layer, we eliminate the need to make each application mobility-aware. In this paper, we design a middleware framework to support user mobility in the ubiquitous computing environment. Its major mobility functions include user-level handoff management and service instantiation across heterogeneous computing platforms. We validate the major mobility functions using our prototype middleware system, and test them on two multimedia applications (Mobile Video Player and Mobile Audio Player). To maximally approximate the real-world user-mobility scenario, we have conducted experiments on a variety of computing platforms and communication paradigms, ranging from T1-connected high-end PC to handheld devices with wireless networks. The results show that our middleware framework is able to provide efficient user mobility support in the heterogeneous computing environment.     

Web services interaction models. Current practice

Each middleware approach has one or more interaction models associated with it that determine how applications built on top of the middleware interact with each other. Message-oriented middleware (MOM) applications interact rather simply, for example, by posting messages to and retrieving messages from queues. Object-oriented middleware applications such as those based on Corba or Enterprise Java Beans (EJB) interact by invoking methods on distributed objects. Because interaction models significantly influence the types of abstractions a middleware system makes available to applications, they figure prominently in determining the breadth and variety of application integration that the middleware supports. As Web services evolve, they too will acquire standard interaction models; otherwise, their use will be limited to small-scale proprietary systems, rather than providing the standards-based "middleware for middleware" for uniting disparate islands of integration. At this point, however, the industry and standards bodies have yet to reach consensus on Web services interaction models. I consider some of the problems associated with a popular current approach to Web services interaction models     

Agent-based Gateway Operating System for RFID-enabled ubiquitous manufacturing enterprise

Capturing and processing of real-time manufacturing shop floor field data is essential in improving the performance of shop floor planning, execution and control. Radio Frequency IDentification (RFID) has enabled real-time information visibility and realized ubiquitous manufacturing enterprises with proper functionalities of Enterprise Information Systems (EISs). This paper presents a flexible, modularized and re-configurable framework for the new generation RFID middleware system, named Gateway Operating System (GOS). It is an overall software solution designed and proposed not only to address basic functions of RFID middleware system, but also to overcome the particular challenges and requirements for real-life manufacturing scenarios. GOS aims to provide an easy-to-deploy, simple-to-use and affordable RFID middleware solution for manufacturing applications. A multi-agent based model, named gateway smart agent manager, is designed to enable the heterogeneous RFID devices in a “Plug and Play” fashion and to cope with the changes from these connected hardware devices. To guarantee the versatility and scalability of GOS, an XML (eXtensible Markup Language) based message exchanging protocol is designed to fulfill the communication and interactions between applications and devices. Based on this protocol, an easy-to-deploy and simple-to-use application manager is built to manage, configure and use the connected devices as well as deployed applications. The proposed GOS will provide a new referenced framework for the development of lightweight RFID middleware system for manufacturing environment.     

A middleware‐transparent approach to developing distributed applications

An innovative middleware‐transparent approach to developing distributed applications is presented. The approach uses an aspect‐oriented software development technique to separate an application's middleware‐independent functionality from its middleware‐specific functionality. Application elements that are specific to the middleware are localized in aspects that can be seamlessly integrated into middleware‐independent application designs. The middleware‐transparent approach is used to decouple business functionality from middleware‐specific functionality. The decoupling allows developers to change middleware application elements without significantly modifying business functionality. Middleware technologies such as Java Remote Method Invocation (RMI), Jini, Simple Object Access Protocol (SOAP) remote procedure call (RPC) and .Net are used as examples to illustrate the approach. Copyright © 2005 John Wiley & Sons, Ltd.     

中间件技术在汽车客运联网售票系统中的应用

如今计算机技术迅速发展,为了解决分布式环境问题,使得中间件技术受到人们广泛的关注。该文根据实际的引用环境,针对具体的应用系统——汽车客运联网售票系统设计和实现方案进行研究。并提出了基于中间件技术的技术方案,解决了汽车客运联网售票系统中的诸如：难以扩充、不易维护、异构环境下难以互操作等问题。     

CADeComp: Context-aware deployment of component-based applications

The expansion of wireless communication and mobile hand-held devices makes it possible to deploy a broad range of applications on mobile terminals such as PDAs and mobile phones. The constant context changes of mobile users oblige them to carry out many deployment tasks of the same application in order to obtain an application whose configuration satisfies the context requirements. The difficulty and the frequency of these deployment tasks led us to study the deployment in a mobile environment and to look for a solution for the automation of the deployment adaptation to the context. This paper studies the deployment sensitivity to the context in order to identify the variable deployment parameters and to analyze the impact of the deployment adaptation on the production life cycle of applications. The contribution made by this paper consists in an innovative middleware entity called Context-Aware Deployment of COMPonents (CADeComp), which can be plugged into existing middleware deployment services. CADeComp defines a flexible data model that facilitates the tasks of component producers and application assemblers by allowing them to specify the meta-information required to adapt the deployment to the context. The advantage of CADeComp is that it is based on reliable adaptive mechanisms that are defined by a platform-independent model according to the MDA approach. We propose a mapping of the CADeComp model to CCM. CADeComp was implemented and evaluated on this platform.     

��DDS: A Middleware for Real-time Wireless Embedded Systems

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.     

网络计算中间件

网络计算中间件是随着互联网的发展而于20世纪90年代兴起的一类基础软件,网络计算中间件为各种网络应用系统的开发、部署、运行和管理提供了有力支持.随着信息网络技术和软件服务工程的快速发展,网络计算中间件又被赋予了新的内涵,首先从网络计算环境出发,就基础中间件、应用集成中间件和领域应用框架的基本概念和主要技术作较全面的诠释;然后聚焦于云计算和物联网等网络计算的热点研究方向,从中间件的角度指出当前值得关注的某些挑战性研究课题和需要深入探索的若干关键技术.