Load-balancing data distribution in publish/subscribe mode

To improve data distribution efficiency a load-balancing data distribution LBDD method is proposed in publish/subscribe mode.In the LBDD method subscribers are involved in distribution tasks and data transfers while receiving data themselves.A dissemination tree is constructed among the subscribers based on MD5 where the publisher acts as the root. The proposed method provides bucket construction target selection and path updates furthermore the property of one-way dissemination is proven.That the average out-going degree of a node is 2 is guaranteed with the proposed LBDD.The experiments on data distribution delay data distribution rate and load distribution are conducted. Experimental results show that the LBDD method aids in shaping the task load between the publisher and subscribers and outperforms the point-to-point approach.

Publish-Subscribe系统支付机制研究

已有的 pub- sub系统支付机制尚有许多缺陷 ,无法满足实际需求 .设计了一套新的基于可信任硬件 (安全协处理器、智能卡 )的支付机制 .这套机制具有良好的保密性、匿名性、高效性和公平性 ,而且实现了时间敏感信息的公平交易 .并对基于内容的 pub- sub系统支付问题给出了完整、有效和实用的解决方案 .

An SDN-Based Publish/Subscribe-Enabled Communication Platform for IoT Services

Publish/subscribe paradigm paves a way to integrate and serve many scalable, inter-operable Internet of Things(IoT) applications. The increasing IoT applications require new properties of publish/subscribe communication model, for example, strict quality of service(Qo S) guarantees, supporting a large number of widely distributed devices, etc. Software Defined Networking(SDN) enables personalized programming and individualized QoS supports for different applications. The combination of the two will have a good prospect. In this paper, we present an IoT-oriented communication platform which combines the publish/subscribe paradigm with SDN, aiming at establishing an IoT ecosystem to facilitate IoT services/applications accessing internet. We design the interaction logic of topic-based publish/subscribe middleware, and describe the setup and maintenance of topology information as well as event routing in detail, considering the characteristics of SDN. Finally, we exemplify its practicability with a deployed District Heating Control and Information Service System(DHCISS) and validity the effectiveness with some experiments.

Cross-Layer QoS Enabled SDN-Like Publish/Subscribe Communication Infrastructure for IoT

Publish/subscribe paradigm is often adopted to create the communication infrastructure of the Internet of Things(IoT)for many clients to access enormous real-time sensor data.However,most current publish/subscribe middlewares are based on traditional ossified IP networks,which are difficult to enable Quality of Service(QoS).How to design the next generation publish/subscribe middleware has become an urgent problem.The emerging Software Defined Networking(SDN)provides new opportunities to improve the QoS of publish/subscribe facilities for delivering events in IoT owing to its customized programmability and centralized control.We can encode event topics,priorities and security policies into flow entries of SDN-enabled switches to satisfy personalized QoS needs.In this paper,we propose a cross-layer QoS enabled SDN-like publish/subscribe communication infrastructure,aiming at building an IoT platform to seamlessly connect IoT services with SDN networks and improving the QoS of delivering events.We first present an SDN-like topic-oriented publish/subscribe middleware architecture with a cross-layer QoS control framework.Then we discuss prototype implementation,including topic management,topology maintenance,event routing and policy management.In the end,we use differentiated services and cross-layer access control as cross-layer QoS scenarios to verify the prototype.Experimental results show that our middleware is effective.

A Publish-Subscribe Networking Architecture for Future Manned Deep Space Exploration

With the further development of the Deep Space Networking(DSN),more and more satellites and space probes will be put into space which makes the DSN more diverse and complex.We argued that Information Centric Networking(ICN)may be a suitable architecture for the DSN.In this paper,a publish-subscribe networking architecture based on ICN is proposed for future manned deep space exploration network.It adopts the publish-subscribe mechanism and decouples the control plane and data plane logically.In the proposed architecture,the improvement of routing is made to tolerant the long propagation delay and frequent link disruptions of deep space.And the multi-source transmission is considered to deal with the large amount of data in the future manned deep space exploration network.We evaluated the feasibility of the architecture and the performance of the protocol stack,the improved routing mechanism and the multi-source transmission.The results indicate that Publish-Subscribe Networking(PSN)can cope with the harsh transmission conditions,and the multi-source transmission can reduce the delivery time of data.It enables the network to allocate and share resources more efficiently and keeps the network well managed.

Providing Delay-Guaranteed Multicast Transmission Services for an SDN-Based Publish/Subscribe System

Providing end-to-end delay guarantees in traditional Internet is a complex task due to the distributed nature of TCP/IP protocols. Software Defined Networking(SDN) gives a new dimension to improve QoS(Quality of Service) as it can benefit from its flexibility, programmability and centralized view. In this paper, we provide delay-guaranteed data transmission service instead of "best efforts" service for a topic-based publish/subscribe system by means of exploring these specific features of SDN. We attribute this routing problem in such conditions to Delay-Constraint Lowest Cost Steiner Tree(DCLCST) problem. To solve it, we compute the shortest delay paths from source node to every subscribe node and the shortest cost paths from every subscribe node to any other node using dijkstra algorithm. Then we construct a delay-constraint least cost steiner tree for per-topic based on these paths as multicast tree. We also present experimental results to demonstrate the effectiveness of the algorithms and methods we proposed.

Embedding Authentication &Authorization in Discovery Protocols for Standard Based Publish/Subscribe Middleware: A Performance Evaluation

Standard based Pub/Sub middleware, such as OMG Data Distribution Service (DDS), could assume a key role in supporting computer communications requiring continuous state information updating, deterministic deadline to data delivering and real time information adjourning. This kind of capability could be well ex-ploited by Peer-To-Peer (P2P) systems, Internet-wide as long as private ones, like in Public Safety or Civil Protection Communication Systems;but Pub/Sub specifications, and DDS/RTPS (Real Time Publish Sub-scribe) as well, usually do not provide Authentication & Authorization (AA) mechanisms. In the present work two important novelties are assessed: a possible scheme to implement AA in DDS/RTPS networks and a time performance evaluation study about embedded Authentication in RTPS.

A Real-Time-Enabled, Blackboard-Based, Publish/Subscribe Architecture for Wireless Sensor Nodes

Wireless sensor network nodes have only limited resources concerning memory and battery life-time. Mem- ory can be efficiently used by sharing data, and the life-time of a battery can be extended, when the node has long power saving sleep-phases. We propose a publish/subscribe architecture that achieves these two aims. The results of our work are of great interest for sensor application developers, giving them now the opportu- nity to use our architecture for sharing data among different applications on the node as well as the different layers of the operating system. We introduce a blackboard which is used for centrally storing published val- ues, like measured data from a monitored sensor. This makes it possible to share stored data without monitoring the sensors once again, which is advantageously concerning power consumption, memory space, and reaction time. Beside the proposed publish/subscribe method for sensor nodes with its notification possibili- ties, our architecture fulfills also real-time requirements. We show how the well-known sensor operating system MANTIS OS can be extended by a real-time enabled, blackboard-based publish/subscribe architect- ture. This architecture and first of all its implementation is of special interest for cross layer optimization of sensor applications. Cross-layer approaches benefit from our architecture because the available implementa- tion can be used as an efficient framework for central storing and managing of shared values.

Research of Publish and Subscribe Model Based on WS-Notification

WS-Notification bundle of standards, WS-BaseNotification, WS-Topics, and WS-BrokeredNotification, can be used as a general purpose publish/subscribe interface for Service Oriented Architectures. We provide an overview of the WS-Notification specification and describe a modified publish and subscribe model based on WS-Notification. The model is an adaptive policy-driven notification framework that can help enterprises to meet the flexibility and respon-siveness requirements of the enterprise. With the modified publish/subscribe model, information consumers can dy-namically and declaratively create and configure entities on their behalves to manage their distribution requirements.

Connected-Vehicle Data Exchanges and Positioning Computing Based on the Publish-Subscribe Paradigm

Connected vehicles for safety and traffic efficient applications require device-to-device connections supporting one-to-many and many-to-many communication, precise absolute and relative positioning and distributed computing. Currently, the 5.9 GHz Dedicated Short Range Communications (DSRC) and 4G-Long-Term Evolution (LTE) are available for connected vehicle services. But both have limitations in reliability or latency over large scale field operational tests and deployment. This paper proposes the device-to-device (D2D) connectivity framework based on publish-subscribe architecture, with Message Queue Telemetry Transport (MQTT) protocol. With the publish-subscribe communication paradigm, road mobile users can exchange data and information in moderate latency and high reliability manner, having the potential to support many Vehicle to Everything (V2X) applications, including vehicle to vehicle (V2V), vehicle to roadside infrastructure (V2I), and vehicle to bicycle (V2B). The D2D data exchanges also facilitate computing for absolute and relative precise real-time kinematic (RTK) posi-tioning. Vehicular experiments were conducted to evaluate the performance of the proposed publish-subscribe MQTT protocols in term of latency and reliability. The latency of data exchanges is measured by One-trip-time (OTT) and the reliability is measured by the packet loss rate (PLR). Our results show that the latency of GNSS raw data exchanges between vehicles through 4G cellular networks at the rate of 10 Hz and the data rates of 10 kbps are less than 300 ms while the reliability is over 96%. Vehicular positioning experiments have also shown that vehicles can exchange raw GNSS data and complete mov-ing-base RTK positioning with the positioning availability of 98%.

Margin optimization algorithm for digital subscriber lines based on particle swarm optimization

The margin maximization problem in digital subscriber line（DSL） systems is investigated.The particle swarm optimization（PSO） theory is applied to the nonconvex margin optimization problem with the target power and rate constraints.PSO is a new evolution algorithm based on the social behavior of swarms, which can solve discontinuous, nonconvex and nonlinear problems efficiently.The proposed algorithm can converge to the global optimal solution, and numerical example demonstrates that the proposed algorithm can guarantee the fast convergence within a few iterations.

Radio map updated method based on subscriber locations in indoor WLAN localization

With the rapid development of wireless local area network （WLAN） technology, an important target of indoor positioning systems is to improve the positioning accuracy while reducing the online calibration effort to overcome signal time-varying. A novel fingerprint positioning algorithm, known as the adaptive radio map with updated method based on hidden Markov model （HMM）, is proposed. It is shown that by using a collection of user traces that can be cheaply obtained, the proposed algorithm can take advantage of these data to update the labeled calibration data to further improve the position estimation accuracy. This algorithm is a combination of machine learning, information gain theory and fingerprinting. By collecting data and testing the algorithm in a realistic indoor WLAN environment, the experiment results indicate that, compared with the widely used K nearest neighbor algorithm, the proposed algorithm can improve the positioning accuracy while greatly reduce the calibration effort.

Broadband ＆ Digital Content-Couple Subscriber Cooperative Relaying Networks for Uplink Transmission using Hierarchical Game Approach

Cooperation allows wireless network users to benefit from various gains such as an in- crease in the achieved rate or an improvement in the bit error rate. In the paper, we propose a distributed Hierarchical Game （HG） theoretic framework over multi-user cooperative communication networks to stimulate cooperation and improve the network performance. First, we study a two- user decision making game in the OFDMA based subscriber cooperative relaying network, in which subscribers transmit their own data in the first phase, while helping to retransmit their partner＇s or choosing to freeride in the second phase. Instead of consulting to a global optimal solution, we decouple the cooperation resource allocation into two level subproblems： a user level Nash game for distributed cooperation decision and a Base Station （BS） level coalition game for centralized resource allocation. In the proposed HG algorithm, where mutual cooperation is preferred and total payoff is transferable, we prove it converges to a unique optimal equilibrium and resolve the subcarrier as-signment and power allocation among the couples. Besides, we discuss the existence of the publishing and rewarding coefficients in order to encourage cooperation. Then, we extend the HG to multi-user cases by coupling among subscribers according to the location information. The simulation results show that the proposed scheme with the distributed HG game achieves a well tradeoff between fairness and efficiency by improving the transmission efficiency of adverse users and outperforms those employing centralized schemes.

Subscribe to Acta Vet Zootech Sinica(AVZS)

The journal is sponsored by the Chinese Association of Animal Science and Veterinary Medicine.It is a national academic journal,founded in 1956,in the area of animal and veterinary medical sciences.The editorial board of the journal,which is located in Institute of Animal Science of the Chinese Academy of Agricultural Sciences,is responsible for the editing and publishing of the journal.

Welcome to Subscribe for Transactions of Nanjing University of Aeronautics & Astronautics

Transactions of Nanjing University of Aeronautics & Astronautics (TNUAA, in English) is a comprehensive academic publication which deals mainly with the research achievements in aeronautics, civil aviation, astronautics and their theoretical basis. It is published by Nanjing University of Aeronautics & Astronautics, and has started its publication since Oct.

Subscribe to China Patents & Trademarks

The Chinese/English bilingual quarterly China Patents & Trademarks is a professional publication sponsored by ChinaPatent Agent(H.K.)Ltd. The journal commenced publication in April 1985 and has been edited and published in HongKong for distribution in China and abroad.

Subscribe to China Patents & Trademarks

The Chinese/English bilingual quarterly China Patents & Trademarks is a professional publicationsponsored by China Patent Agent (H.K.) Ltd.The journal commenced publication in April 1985 and hasbeen edited and published in Hong Kong for distribution in China and abroad.The main contents carried by China Patents & Trademarks are:guidelines,policies,laws and regula-tions relevant to intellectual property,economy and trade in China;matters related to the practical

Subscribe to China Patents & Trademarks

The Chinese/English bilingual quarterly China Patents & Trademarks is a professional publicationsponsored by China Patent Agent(H.K.)Ltd.The journal commenced publication in April 1985 and hasbeen edited and published in Hong Kong for distribution in China and abroad.The main contents carried by China Patents & Trademarks are:guidelines,policies,laws and regula-tions relevant to intellectual property,economy and trade in China;matters related to the practical