Energy-efficient networking: past, present, and future

The twenty-first century has witnessed major technological changes that have transformed the way we live, work, and interact with one another. One of the major technology enablers responsible for this remarkable transformation in our global society is the deployment and use of Information and Communication Technology (ICT) equipment. In fact, today ICT has become highly integrated in our society that includes the dependence on ICT of various sectors, such as business, transportation, education, and the economy to the point that we now almost completely depend on it. Over the last few years, the energy consumption resulting from the usage of ICT equipment and its impact on the environment have fueled a lot of interests among researchers, designers, manufacturers, policy makers, and educators. We present some of the motivations driving the need for energy-efficient communications. We describe and discuss some of the recent techniques and solutions that have been proposed to minimize energy consumption by communication devices, protocols, networks, end-user systems, and data centers. In addition, we highlight a few emerging trends and we also identify some challenges that need to be addressed to enable novel, scalable, cost-effective energy-efficient communications in the future.     

An Intents-based approach for dynamic service discovery

Service discovery has been a very active research field attracting many researchers around the world. Most of the previous research efforts on service discovery have been based on the ternary classification of participant roles in web services, including service providers, brokers, and consumers. This classification is insufficient because it fails to make a difference between application developers and end users who both belong to service consumers. As a result, application developers usually take the responsibility of seeking services while end users who ultimately use the application are ignored. In order to address this issue, this paper presents an Intents-based approach for dynamic service discovery. The proposed approach is motivated from two industrial protocols: Android Intents and web Intents. It improves the two protocols by a generic model from the aspects of architecture, intent messages and their resolving process, Intents services, and user agents. It classifies the implicit intents into authoritative and naïve intents and is compatible with the current web service triangular architecture. This paper also illustrates a way of creating Intents services from SOAP and REST web services and presents two cases to demonstrate some benefits of the proposed approach.     

An abstract model of service discovery and binding

We propose a formal operational semantics for service discovery and binding. This semantics is based on a graph-based representation of the configuration of global computers typed by business activities. Business activities execute distributed workflows that can trigger, at run time, the discovery, ranking and selection of services to which they bind, thus reconfiguring the workflows that they execute. Discovery, ranking and selection are based on compliance with required business and interaction protocols and optimisation of quality-of-service constraints. Binding and reconfiguration are captured as algebraic operations on configuration graphs. We also discuss the methodological implications that this model framework has on software engineering using a typical travel-booking scenario. To the best of our knowledge, our approach is the first to provide a clear separation between service computation and discovery/instantiation/binding, and to offer a formal framework that is independent of the SOA middleware components that act as service registries or brokers, and the protocols through which bindings and invocations are performed.     

A telematics service discovery platform using the distributed peer‐to‐peer networking system

In this paper, a distributed telematics peer‐to‐peer networking system is proposed to provide an efficient and feasible service discovery mechanism for mobile users. When mobile users travel on the road, they may request for some services from service providers to meet their demands. Mobile users in vehicles are assumed to go through a lot of regions, in which each region is associated with a region server. Related information of all service providers in a region is stored in its region server, and each region server is in charge of the service discovery requests from all vehicles located in its region. This paper focuses on the issues of developing a distributed peer‐to‐peer telematics service discovery networking system over the vehicular network environment for mobile users. To provide the communication mechanism for telematics service discovery among region server, mobile users, and service providers, the Telematics Service Markup Language is proposed. According to clients' demands, three types of query scenarios are proposed, which are (1) reference point based query, (2) continual query, and (3) route‐based query. Finally, we present usage examples and system implementation of distributed telematics peer‐to‐peer. Copyright © 2012 John Wiley & Sons, Ltd.     

Security in local area networking

As networks become larger and more complex, the question of security and the prevention of network access by unauthorized users are real concerns. Software is now available which allows the PC user to set up a network offering similar advantages to those already enjoyed by minicomputer and mainframe users.     

基于泛洪区域限定的改进DSR节能组网

针对动态源自组网(Dynamic Source Routing,DSR)因泛洪组网请求(Route Request,RREQ)而产生的高组网能耗问题,提出基于区域的发现机制的DSR组网(Zone-based Route Discovery Mechanism,ZRDM)。ZRDM组网依据节点的环境以及邻居节点的分布情况,将节点网络区域划分为3个子区域。每个节点数据含一个邻居表,并将邻居节点划分为3个子区域。同时DSR组网只允许部分节点传输RREQ数据。仿真结果表明,提出的ZRDM组网降低了能耗,提高了数据传递率。在节点数为140时,相比DSR组网,ZRDM组网的归一化能耗下降了47.8%,数据传递率提高约2.78%。     

Enhanced service discovery in Bluetooth

The rapid evolution and expansion of wireless-enabled environments have increased the need for sophisticated service discovery protocols (SDPs). Typically, service discovery involves a client, service provider, and lookup or directory server. The paper discusses Bluetooth (http://www.bluetooth.com) short-range wireless technology. The Bluetooth protocol stack includes specifications that define the SDP, RFCOMM (for cable replacement), the logical link control and adaptation protocol (L2CAP), a host controller interface (HCI), the link manager protocol (LMP), the base-band protocol, and a radio frequency (RF) protocol. The paper considers Bluetooth service discovery improvements with semantic matching     

服务发现技术中的服务描述和服务匹配技术

普及计算环境中的设备和应用需要通过服务发现来获得其它设备和应用所提供的服务。在服务发现技术中,服务描述、需求描述和服务匹配是迫切需要解决的关键问题。但由于服务和需求的多样性和复杂性,以及普及计算环境的动态性和异构性,使这些问题更加困难和复杂。所以,寻找一种灵活高效而又准确的方式来进行服务描述、需求描述,进而进行服务匹配,具有非常重要的意义。对现有多种服务发现系统中的服务描述需求描述和服务匹配技术进行比较分析,指出了现有解决方案的一些不足,并对未来的研究进行了展望。     

信息中心网络实时业务支持技术

NDN针对不同业务类型特征和内容语义,单一地执行相同的请求应答模式、缓存和路由决策,难以实现实时业务的高效内容分发,针对该问题提出了信息中心网络实时业务支持技术RTSS。利用长久兴趣报文的请求模式减少了兴趣报文开销;快速转发的数据响应策略降低查表和缓存的响应延迟;基于改进蚁群优化算法的路由转发方式提高了实时业务的服务质量保障水平。仿真结果表明RTSS方案以有限的计算和存储代价,降低了实时业务的平均响应时延。     

DaaS: Cloud-based mobile Web service discovery

The proliferation of smartphones and the recent advancement in ubiquitous wireless access have made mobile Web services more possible than ever before. However, finding relevant Web services that can match requests and fit user context remains a major concern. The challenges facing Web service discovery are further magnified by the stringent constraints of mobile devices and the inherit complexity of wireless heterogeneous networks. Cloud computing, with its flexible design and theoretically unlimited computing resources, is a viable approach to bootstrapping Web service discovery. The cloud can build bridges between mobile devices, as a convenient ubiquitous interface, and a backbone infrastructure with abundant computing resources. This paper introduces “Discovery as a service (Daas)”, a novel cloud-based discovery framework that addresses the core components of mobile Web service discovery. The DaaS framework lays the foundation of efficient mobile Web service discovery that takes into consideration user preferences and context. The experimental validation and performance evaluation demonstrate that DaaS can effectively rank relevant services according to the various user context and preferences, in addition to enhancing the precision of the discovered services. The prototype also shows that Web service clustering for discovery significantly improves the overall response time, while the cloud maintains scalability according to prespecified performance criteria.     

Local area networking: Overview of current technologies used in LANs

The article describes the most common forms of local area network concentrating on the token passing ring.     

MELEACH 一个高效节能的WSN路由协议

无线传感器网络(简称WSN)一种资源严重受限的网络,特别是在供能方面.因此,如何有效地使用传感器节点的能量以延长WSN的生存时间,一直是WSN路由协议研究所关注的焦点. LEACH[1-2]作为一种WSN路由协议,以其优秀的节能效果和简单的规程而得到广泛的认可.本文基于LEACH提出了一个新的路由协议MELEACH(More Energy-efficient LEACH). 通过进一步缩短无线通信的平均距离并进一步改善节点间的负载平衡, MELEACH在保持LEACH原有优点的基础上实现了更好的节能效果.分析和实验表明,一个WSN在MELEACH下的生存时间要比在LEACH中长50%以上.     

网格环境下一种远程教育服务发现机制

网格环境下的远程教育出现对网格服务发现提出了挑战,UDDI上基于关键词和简单分类的服务发现机制已经不能很好满足需要。在分析现有相关研究的基础上,提出了基于Bloom过滤器的网格服务发现机制。通过对网格服务立体性分析,指出可对网格服务发布构建Bloom过滤器,给出一个具有高度空间相关性的服务发现方法。理论分析与实验表明,该方法是有效可行的。     

Developing reusable simulation core code for networking: The grid resource discovery example

In this work, first, we present a grid resource discovery protocol that discovers computing resources without the need for resource brokers to track existing resource providers. The protocol uses a scoring mechanism to aggregate and rank resource provider assets and Internet router data tables (called grid routing tables) for storage and retrieval of the assets. Then, we discuss the simulation framework used to model the protocol and the results of the experimentation. The simulator utilizes a simulation engine core that can be reused for other network protocol simulators considering time management, event distribution, and a simulated network infrastructure. The techniques for constructing the simulation core code using C++/CLR are also presented in this paper.     

Joint semantic similarity assessment with raw corpus and structured ontology for semantic-oriented service discovery

Semantic-oriented service matching is one of the challenges in automatic Web service discovery. Service users may search for Web services using keywords and receive the matching services in terms of their functional profiles. A number of approaches to computing the semantic similarity between words have been developed to enhance the precision of matchmaking, which can be classified into ontology-based and corpus-based approaches. The ontology-based approaches commonly use the differentiated concept information provided by a large ontology for measuring lexical similarity with word sense disambiguation. Nevertheless, most of the ontologies are domain-special and limited to lexical coverage, which have a limited applicability. On the other hand, corpus-based approaches rely on the distributional statistics of context to represent per word as a vector and measure the distance of word vectors. However, the polysemous problem may lead to a low computational accuracy. In this paper, in order to augment the semantic information content in word vectors, we propose a multiple semantic fusion (MSF) model to generate sense-specific vector per word. In this model, various semantic properties of the general-purpose ontology WordNet are integrated to fine-tune the distributed word representations learned from corpus, in terms of vector combination strategies. The retrofitted word vectors are modeled as semantic vectors for estimating semantic similarity. The MSF model-based similarity measure is validated against other similarity measures on multiple benchmark datasets. Experimental results of word similarity evaluation indicate that our computational method can obtain higher correlation coefficient with human judgment in most cases. Moreover, the proposed similarity measure is demonstrated to improve the performance of Web service matchmaking based on a single semantic resource. Accordingly, our findings provide a new method and perspective to understand and represent lexical semantics.     

服务发现机制研究进展*

以现有服务发现机制发展过程为主线,重点分析了独立服务发现平台和集成式服务发现平台的主要工作机制和优缺点,在归纳和总结现有服务发现机制普遍采用烟囱式、一视同仁以及叠加式策略等问题的同时,提出了未来服务发现机制的研究方向。     

Semantics in service discovery and QoS measurement

For the vision of ubiquitous, easily invokable Web services to become a reality, it will be necessary for service requesters to compare the quality-of-service (QoS) aspects of various services. So standardized QoS information must become a part of the service discovery process. This article surveys the current research on QoS and service discovery, including ontologies such as OWL-S and DAML-S. The authors then propose their own ontology, DAML-QoS, which provides detailed QoS information in a DAML format.     

Integrating service discovery technologies in OSGi platform

This paper describes the service discovery and interaction for home network devices using heterogeneous standards and protocols. OSGi was proposed to allow several kinds of services coming from different providers to be loaded and run on a gateway. We present a residential gateway based on the OSGi architecture for a smart home network. We combine the SLP SA/DA, the UPnP control point and the SIP UA into the gateway to achieve automated device discovery, registry, and management. Application examples are introduced and the implementation results show that our gateway can provide automatic heterogeneous service or device discovery, registry, and management.