Tight end-to-end per-flow delay bounds in FIFO multiplexing sink-tree networks

Aggregate scheduling has been proposed as a solution for achieving scalability in large-size networks. However, in order to enable the provisioning of real-time services, such as video delivery or voice conversations, in aggregate scheduling networks, end-to-end delay bounds for single flows are required. In this paper, we derive per-flow end-to-end delay bounds in aggregate scheduling networks in which per-egress (or sink-tree) aggregation is in place, and flows traffic is aggregated according to a FIFO policy. The derivation process is based on Network Calculus, which is suitably extended to this purpose. We show that the bound is tight by deriving the scenario in which it is attained. A tight delay bound can be employed for a variety of purposes: for example, devising optimal aggregation criteria and rate provisioning policies based on pre-specified flow delay bounds.     

Peer-to-Peer and fault-tolerance: Towards deployment-based technical services

For effective components, non-functional aspects must be added to application functional code. Likewise, enterprise middleware and component platforms, in the context of Grids, services must be deployed at execution in component containers in order to implement those aspects without modifications in the application code.This paper proposes an architecture for defining, configuring, and deploying such Technical Services in a Grid platform.     

A lightweight middleware framework for vehicle networking application

There is a growing need for Vehicle Networking Applications (VNAs) development that does not require users to learn the details of VNA data processing and message transfer. VNAs have some special requirements differing from other general‐purpose applications, such as real‐time performance, extensibility, compatibility, and reusability. To meet with these requirements of the VNAs, we propose a lightweight middleware framework for VNAs in this article. In the middle framework, we design multi‐layer middleware architecture to separate VNAs from the software platform and to improve the adaptability for the heterogeneous network and various vehicle networking communication protocols. Meanwhile, the middleware architecture consists of fixed and exchangeable modules to improve the middleware reusability. And the component bus is presented in a framework to standardize component interfaces to improve the extensibility of middleware. The framework has an efficient and simple structure to guarantee the real‐time performance of data processing and message transferring. This middleware also provides a uniform communication mechanism to be compatible with other existing middleware. In this article, we describe the design ideas and the composition of each module in the middleware framework, and analyze the data flow in communication process. We also develop the middleware prototypes to verify the feasibility of the middleware framework. Copyright © 2015 John Wiley & Sons, Ltd.     

基于RapidIO的实时CORBA中间件实现

为了解决CORBA传统传输协议TCP/IP的时延不确定问题,提出了使用基于点对点的包交换RapidIO协议来替代TCP/IP的方法,研究了CORBA的可插拔传输协议框架,从而实现了CORBA报文在RapidIO总线上的传输。测试结果显示,基于RapidIO的CORBA实时性优于基于TCP/IP的CORBA。     

Enabling portability in advanced information-centric services over structured peer-to-peer systems

A common factor among all the existing distributed, peer-to-peer systems is their lack of genericity. Typically, information-centric services (such as range queries) are deployed ad-hoc onto a specific peer-to-peer overlay. These kinds of solutions make them probably efficient but non-portable to other peer-to-peer infrastructures, and so the services and applications constructed over them. We do believe, instead, that a peer-to-peer-generic solution is feasible. In this paper, we tackle the genericity and portability issue specifically on structured peer-to-peer networks (SPNs).To do so, we introduce a distributed 3-layer architecture, which abstracts applications (on top of the architecture) and the peer-to-peer network currently in use (in the bottom layer). Our middleware appears in the middle layer, which is responsible to address two major challenges: (i) supporting complex, multi-dimensional application data domains and (ii) performing efficiently for a wide variety of information-centric services in the large scale.Broadly speaking, information-centric services are classified as data management (such as range or spatial queries) and content distribution services (like publish/subscribe), and our middleware is an umbrella for all them. Notice that data management services are based on the pull mode (i.e., a user lookups information previously stored in the system), whilst content distribution services obey to a push mode (i.e., the system delivers the information timely to users).The benefits of our approach are clear: (i) Our middleware can be easily deployed over existing SPNs, guaranteeing the portability of a critical mass of services and end-user applications; (ii) Several services can be added to the middleware, which will facilitate the appearance of new synergies; and (iii) our middleware deals with the application data domain transparently to services and applications, including the necessary algorithms for services to be efficiently deployed into our middleware.     

Delay-tolerant delivery of quality information in ad hoc networks

We investigate the delivery of information in ad hoc networks. We consider information sources and information consumers, and the network in between. Information has a certain quality indicator that fades over time. Consumers (applications that process incoming data) can receive and process disseminated information from its generation time until the associated quality reaches the lowest possible level. We adopt optimal stopping theory and an optimal online search algorithm in order to study the problem of optimally scheduling information consumption. The assumptions of our study include an efficient epidemic information dissemination scheme, which is a popular scheme for wireless sensor networks nowadays. We adopt the latter scheme for a combined setting where receiving nodes delay the reporting of information to applications in search for better quality while the overall network optimizes transmissions through the epidemic abstraction. Our findings are quite promising for the engineering of delay-tolerant applications (and the relevant middleware) in ad hoc networks.     

An approach to domain-based scalable context management architecture in pervasive environments

In pervasive environments, context management systems are expected to administrate large volume of contextual information that is captured from spatial to nonspatial elements. Research in context-aware computing produced a number of middleware systems for context management to intermediate the communications between applications and context providers. In particular, in pervasive environments, the design of distributed storage, retrieval and propagation mechanisms of context information across domains is vital. In this paper, we propose a domain-based approach to address the requirements of scalable distributed context management, cross-domain efficient context information dissemination and domain-based privacy policy enforcement. We propose infinitum, a middleware architecture that incorporates the management and communication benefits of the Google Wave Federation Protocol, while also taking advantage of the semantic and inference benefits of ontology-based context models. This architecture establishes a robust cross-domain scalable context management and collaboration framework, which has been implemented and evaluated in a real-life application of “SMART University” to support virtual team collaboration.     

轻量级WebGIS中间件的设计与实现

GIS中间件是实现多层分布式GIS应用的核心，能有效地提供各类空间信息服务，屏蔽不同空间数据源的差异性。该文以GIS中间件技术的研究为起点，提出了WebGIS中间件框架BSGIS，对BSGIS的体系结构和处理流程进行阐述，介绍了BSGIS的具体实现，并将其应用于政府道路管理系统之上，证明了该框架在实际应用中的可行性，解决了WebGIS开发复杂性高、成本大、成功率低等问题。     

高强度的移动通信安全中间件架构

简要分析了GSM/UMTS的安全机制以及缺陷,针对这些问题提出了基于端到端安全机制的高强度的移动通信安全中间件架构。介绍了架构的组成和安全机制,设计了所需的鉴权和密钥协商机制,同时介绍和分析了架构的安全机制中所需的加密算法和完整性控制方案。     

网络透视的研究和发展

网络透视是一新兴网络课题,旨在通过端到端的方法得到链联级的性能特性,比如:丢包率和平均延迟等。所得到的信息对进一步认识网络的动态性质极有帮助,并且将指导人们从事下一代网络的开发与研究。该文将简要论述这方面的研究情况,以期促进国内有关研究机构对此方面的研究予以重视。     

SPAD: A distributed middleware architecture for QoS enhanced alternate path discovery

In the next generation Internet, the network will evolve from a plain communication medium into one that provides endless services to the users. These services will be composed of multiple cooperative distributed application elements. We name these services overlay applications. The cooperative application elements within an overlay application will build a dynamic communication mesh, namely an overlay association. The Quality of Service (QoS) perceived by the users of an overlay application greatly depends on the QoS experienced on the communication paths of the corresponding overlay association. In this paper, we present super-peer alternate path discovery (SPAD), a distributed middleware architecture that aims at providing enhanced QoS between end-points within an overlay association. To achieve this goal, SPAD provides a complete scheme to discover and utilize composite alternate end-to-end paths with better QoS than the path given by the default IP routing mechanisms.     

Bailout forward contracts for edge-to-edge internet services

Despite the huge success of the Internet in providing basic communication services, its economic architecture needs to be upgraded so as to provide end-to-end guaranteed or more reliable services to its customers. Currently, a user or an enterprise that needs end-to-end bandwidth guarantees between two arbitrary points in the Internet for a short period of time has no way of expressing its needs. To allow these much needed basic services, we propose a single-domain edge-to-edge (g2g) dynamic capacity contracting mechanism, where a network customer can enter into a bandwidth contract on a g2g path at a future time, at a predetermined price. For practical and economic viability, such forward contracts must involve a bailout option to account for bandwidth becoming unavailable at service delivery time, and must be priced appropriately to enable Internet Service Providers (ISPs) manage risks in their contracting and investments. Our design allows ISPs to advertise point-to-point different prices for each of their g2g paths instead of the current point-to-anywhere prices, allowing discovery of better end-to-end paths, temporal flexibility and efficiency of bandwidth usage. We compute the risk-neutral prices for these g2g bailout forward contracts (BFCs), taking into account correlations between different contracts due to correlated demand patterns and overlapping paths. We apply this multiple g2g BFC framework on network models with Rocketfuel topologies. We evaluate our contracting mechanism in terms of key network performance metrics like fraction of bailouts, revenue earned by the provider, and adaptability to link failures. We also explore the tradeoffs between complexity of pricing and performance benefits of our BFC mechanism.     

移动ERP系统中集成中间件的设计与实现*

针对移动企业资源计划（ERP）应用中存在的异构问题,提出了一种具有良好可扩展性和即插即用特性的集成中间件;设计了该集成中间件的组成结构,给出了各个组成结构的详细设计方案,并对其关键组件进行了具体实现。该集成中间件为完成数据和信息的有效共享提供了一种行之有效的途径,在一定程度上完善了移动ERP的体系结构,并结合实际项目验证了该集成中间件的可行性。     

FamiWare: a family of event-based middleware for ambient intelligence

Most of the middlewares currently available focus on one type of device (e.g., TinyOS sensors) and/or are designed with one requirement in mind (e.g., data management). This is an important limitation since most of the AmI applications work with several devices (such as sensors, smartphones or PDAs) and use a high diversity of low-level services. Ideally, the middleware should provide a single interface for accessing all those services able to work in heterogeneous devices. To address this issue, we propose a family of configurable middleware (FamiWare) with a really flexible architecture, instead of building a single version of a middleware with a rigid structure. In this work, we present the architecture of our middleware that can be configured, following a Software Product Line approach, in order to be instantiated in a particular device fulfilling specific application requirements. Furthermore, we evaluate that the decisions taken at architecture and implementation are the adequate ones for this kind of constrained devices.     

Context- and social-aware middleware for opportunistic networks

Opportunistic networks are multi-hop ad hoc networks in which nodes opportunistically exploit any pair-wise contact to share and forward content, without requiring any pre-existing Internet infrastructure. Opportunistic networks tolerate partitions, long disconnections, and topology instability in general. In this challenging environment, leveraging users’ mobility represents the most effective way to deliver content to interested users. In this paper we propose a context- and social-aware middleware that autonomically learns context and social information on the users of the network, and that uses this information in order to predict users’ future movements. In order to evaluate the proposed middleware on a realistic scenario, we have designed and implemented a context- and social-aware content sharing service, exploiting the functionality of the middleware. Both the middleware and the content sharing service have been integrated with an existing data-centric architecture (the Haggle architecture) for opportunistic networks. Finally, we have validated the proposed content sharing application on a small-scale testbed and, on a larger scale, we have investigated the advantages provided by context- and social-aware sharing strategies by means of extensive simulations. The main result of this paper is the definition and implementation of a context- and social-aware middleware able to share context information with all the interested components improving the efficiency and performances of services and protocols in opportunistic networks. With respect to content sharing strategies that do not exploit context and social information, we have obtained up to 200% improvements in terms of hit rate (probability that users receive the content they request) and 99% reduction in resource consumption in terms of traffic generated on the network.     

支持多种终端的多媒体展示中间件

为了规范多媒体业务开发,首先分析传统信息展示系统的弊端,在此基础上,提出基于中间件技术的多媒体展示中间件,重点讨论中间件的系统架构和核心模块实现。为了验证展示中间件的跨平台性,使用展示中间件的验证系统IMPS对其进行实验,通过数据分析证明了中间件在不同平台运行稳定可靠。     

基于离散过程跟踪的自动识别处理中间件

为解决通用中间件与应用层缺乏关联的问题,提出一种基于离散过程跟踪的自动识别处理中间件。给出中间件的体系结构,设计数据计算服务算法,采用面向服务架构,提供数据读入接口,以此实现数据过滤、Web计算服务、数据访问适配器、消息事件等功能。实验结果表明,该中间件具有较好的适应性。     

What middleware for network centric operations?

The main intent of this paper is to address the issue of middleware in network centric operations. To this end, we characterize a set of Information Technology capabilities that such a middleware should implement. Afterwards, we will discuss the design and architectural aspects of these capabilities. This will lead us to an efficient and practical decision support system that we call a digital cockpit. The latter is essentially a multi-tier IT platform that provides a plethora of services such as: data and service integration, monitoring, analysis, and process optimization. Moreover, the platform uses advanced display mechanisms to render the information in a structured and navigational representation that offers the possibility to drill down into the details. A significant subgoal of the paper is to discuss the quality attributes of such an NCO middleware. Finally, we present the results of an implementation of the aforesaid platform architecture.