基于PSO的无线Mesh网关优化部署算法

无线Mesh网关的优化部署目标是对一给定的无线Mesh网络,合理地确定网关部署的方案,在满足用户通信时延、通信带宽以及网关相关属性约束(如网关的度,簇度数)的前提下,使得网关数量最少、网关间负载均衡以及总体通信代价最小。利用粒子群算法在多目标寻优方面的优势,提出了基于粒子群的无线Mesh网关优化部署算法。对粒子的速度、速度的相关运算规则和粒子的运动方程进行了重新定义与设计,然后提出了基于网关启发式初步部署与优化的二阶段粒子群优化算法。理论分析与仿真实验表明,基于PSO的优化算法得到的网关数量不劣于其它算法得到的结果,而且在其它性能指标方面:通信代价、网关节点数量、负载均衡方面优势明显,与Recursive_DS算法的相比分别提高了38.15%,7.85%和7.3%。     

基于移动Ad Hoc路由技术的无线局域网

无线网关的覆盖范围受到衰减和干扰等因素的限制，因此部署无线网关的代价是比较高的。为了减少所需的网关数，同时又能保持相同的覆盖范围，可以将Adhoc路由协议集成到无线局域网的网络协议中，从而使不在网关直接传输范围内的结点也能够间接地获取Internet连接。详细讨论了这种无线局域网的地址配置和路由问题。仿真结果验证了该方法的有效性。     

基于多PLC协同的边缘计算网关测试平台设计

在工业企业数字化转型的大趋势下,边缘计算网关作为数据采集与转发的重要设备,需求快速上升。但目前国内工业企业自动化程度较低,工业互联网标准碎片化问题突出,边缘计算网关需要面对异构设备接入数量不一、工业协议多样、多数据并行采集的工业现场环境。然而,目前缺乏实验室环境下对边缘计算网关异构设备接入能力、工业协议兼容能力及并行数据采集能力快速验证方法的相关研究。设计了一种多PLC协同测试方法实现对工业数据采集现场环境的模拟,采用可视化测试用例开发、多协议融合、多PLC并行管控技术,在实验室条件下实现了对边缘计算网关的多设备、多协议、多数据采集边缘计算能力的快速测试验证。并搭建了一套基于多PLC协同的边缘计算网关测试平台,通过并行数据采集和协议融合等实验,证明该平台能够为工业企业提供快捷有效的边缘计算网关验证,能够极大地降低工业企业试错成本,助力企业数字化转型。     

CSCW的可扩展自组网通信环境的研究

简要分析了CSCW和自组网的关系，讨论了使用成簇方法的自组网体系结构，提出了现有成簇方法的缺点．因为现有的成簇方法未考虑网关选举问题．造成了两个簇首之间的多个冗余网关的存在．该设计提出并．实现了一个分布的网关选举策略，每两个相邻簇对之间仅仅需要一个网关．为了保持网关节点的稳定性，使网关节点保持更长的生存时间，网关选举采用节点最大权原则．仿真结果表明，该方法可以有效的减少包转发数量．有助于减少维持拓扑信息的复杂度．通过限制重播节点为簇首和网关的机制，取得了比洪泛更好的可扩展性．     

Energy-efficient bootstrapping for wireless sensor networks

Wireless sensor networks are poised for increasingly wider uses in many military and civil applications. Such applications has stimulated research in a number of research areas related to energy conservation in such networks. Most such research focuses on energy saving in tasks after the network has been organized. Very little attention has been paid to network bootstrapping as a possible phase where energy can be saved. Bootstrapping is the phase in which the entities in a network are made aware of the presence of all or some of the other entities in the network. This paper describes a bootstrapping protocol for a class of sensor networks consisting of a mix of low-energy sensor nodes and a small number of high-energy entities called gateways. We propose a new approach, namely the slotted sensor bootstrapping (SSB) protocol, which focuses on avoiding collisions in the bootstrapping phase and emphasizes turning off node radio circuits whenever possible to save energy. Our mechanism synchronizes the sensor nodes to the gateway’s clock so that time-based communication can be used. The proposed SSB protocol tackles the issue of node coverage in scenarios, when physical device limitations and security precautions prevent some sensor nodes from communicating with the gateways. Additionally, we present an extension of the bootstrapping protocol, which leverages possible gateway mobility.     

MANET与Internet互联时的增强型机制研究

已有的移动自组网与Internet的互联协议由于无法克服网关发现过程中的单向链路并且因盲目转播网关发现报文形成广播风暴等原因而致使性能严重恶化。该文提出了一种增强型的综合互联协议，该协议一方面采用效率较高的综合方式进行网关发现，另一方面则通过交换携带有对称邻居列表和非对称邻居列表的HELLO分组而有效克服了网关发现过程中的单向链路，同时抑制了广播风暴的形成。基于NS2的仿真结果显示该增强型的综合互联协议在不引入新控制分组的前提下能显著提升互联性能，降低互联开销。     

Integration with Web services

There's a difference between what we'd like our enterprise computing systems to be and what they really are. We like to envision them as orderly multitier arrangements comprising software buses, hubs, gateways, and adapters - all deployed at just the right places to maximize scale, load, application utility, and ultimately, business value. Unfortunately, we know that there's a wide gulf between this idealistic vision and reality. In practice, our enterprise computing systems typically are tangles of numerous technologies, protocols, and applications, often hastily hard-wired together with inflexible point-to-point connections. The whole point of middleware is to hide the diversity and complexity of the computing machinery underneath it. By adopting the abstractions that middleware provides, we're supposedly isolating our applications from the variety of ever-changing hardware platforms, operating systems, networks, protocols, and transports that make up our enterprise computing systems. We can use Web services to provide "middleware for middleware" abstraction layer for modern integration applications.     

IPSec-VPN与几种典型网络协议的互操作问题

分析了IPSec-VPN在一些特殊网络应用场景中与几种典型网络协议的互操作问题,并讨论了一些可行的解决方案。研究内容包括：在IPv4网络中与NAT网关互操作问题;在无线网络场景中与性能提升代理互操作问题;在动态拓扑VPN网络环境中与动态路由协议互操作问题;在移动网络环境中与移动IP协议互操作问题。     

Phoebus: A system for high throughput data movement

Phoebus is an infrastructure for improving end-to-end throughput in high-bandwidth, long-distance networks by using a “session layer” protocol and “gateways” in the network. Phoebus has the ability to dynamically allocate network resources and to use segment-specific transport protocols between gateways, as well as to apply other performance-improving techniques on behalf of the user. We have developed interfaces to Phoebus to allow its use in various real applications and data movement services. This paper extends our earlier work with tests of Phoebus-enabled applications on both real-world networks as well as over configurable network testbeds that allow us to modify latency and loss rates. We demonstrate that Phoebus improves the performance of bulk data transfer in a variety of network configurations and conditions.     

An optimal cluster based security and resilience of smart home environments using hybrid soft computing techniques

Smart home is the main part of smart intelligent system here the remote users share the sensitive information through an insecure medium to access such smart devices, which becomes security issues. The recent user authentication protocols have used to solve those problems and provide secure communication. Consumer traffic increase the risk of illegal user as legal user and radio channels are extra vulnerable to listeners. For further security enhancement, we proposed an optimal cluster based remote user authentication (OCRUA) protocol for smart home environment using hybrid soft computing techniques. The first contribution of proposed protocol is to introduce squirrel induced butterfly optimization (SBO) algorithm for cluster formation, which groups the smart devices. Then, we compute the cluster head (CH) using the teacher learning based deep neural network (TL-DNN) based on multiple design constraints. The second contribution is to illustrate remote user authentication using optimal elliptic curve cryptography (OECC) which encrypts the sensitive information before forward to gateway. At long last, the concert of planned OCRUA protocol evaluates use different replication scenarios and shows the effectiveness over the existing state-of-art protocols.     

C3: an energy-efficient protocol for coverage,connectivity and communication in WSNs

The lower layer of ubiquitous and pervasive systems consists of wireless ad hoc and sensor networks. In wireless sensor networks (WSNs), sensors consume most of their energy in data transmission and idle listening. Hence, efficient usage of energy can be ensured by improved protocols for topology control (i.e., coverage and connectivity), sleep scheduling, communication, and aggregation and compression of data. Though several protocols have been proposed for this purpose, they are not energy-efficient. We propose an integrated and energy-efficient protocol for Coverage, Connectivity, and Communication (C3) in WSNs. The C3 protocol uses received signal strength indicator to divide the network into virtual rings, defines clusters with clusterheads more probably at alternating rings, defines dings that are rings inside a cluster and uses triangular tessellation to identify redundant nodes, and communicates data to sink through clusterheads and gateways. The proposed protocol strives for near-optimal deployment, load balancing, and energy-efficient communication. Simulation results show that the C3 protocol ensures partial coverage of more than 90 % of the total deployment area, ensures one connected network, and facilitates energy-efficient communication while expending only one-fourth of the energy compared to other related protocols such as the coverage and connectivity protocol, and the layered diffusion-based coverage control.     

Trends in mobile satellite technology

Demand for sophisticated personal communication services has changed communications satellite design. Satellites have moved closer to the Earth to improve communication speed and enable personal communication services. However, in so doing, they require more computing resources and more sophisticated protocols to handle intersatellite communications. This article examines the trends in communications satellite deployment and the resulting requirements for network protocols that are intended to support space communications. It reports the findings of a joint DoD/NASA effort to identify what parts of the seven-layer OSI protocol model can be adapted to support more sophisticated space applications     

单个ZigBee 网络的多网关系统

单个ZigBee网络往往只有一个网关．单网关系统可能存在一些问题,如大数据量造成网络延时,网关节点坏掉使整个网络瘫痪等．为解决这些问题,提出了一种在单个ZigBee网络中设置多个网关的设计方法．将网络中所有传给单个网关的数据分成几部分分别传送给多个网关,各网关将数据进行转换后传输到以太网,PC端服务器通过TCP／IP协议汇总网关数据后集中处理．介绍了多网关系统的组成和工作原理,完成了系统软硬件设计,并详细描述了路由对最佳网关的选择过程,最后对系统进行了测试．测试结果表明,该多网关系统运行稳定,能有效弥补单网关ZigBee网络的不足．     

Dense Indoor Sensor Networks: Towards passively sensing human presence with LoRaWAN

Sensors have become ubiquitous in buildings but are rarely connected to a network, and their potential to analyse the performance, use, and interaction with a building is not yet fully realised. In the coming years, we expect sensors in buildings to become part of the Internet of Things (IoT) and grow in numbers to form a Dense Indoor Sensor Network (DISN) that allows for unprecedented analysis of the performance, use, and interaction with buildings. Multiple technologies vie for leading this transformation. We explore Long Range Wide Area Network (LoRaWAN) as an alternative for creating indoor sensor networks that extends beyond its original long-distance communication purpose. For the present paper, we developed a DISN with 390 sensor nodes and four gateways and empirically evaluated its performance for two years. Our analysis of more than 86 million transmissions revealed that DISNs achieve a much lower distance coverage compared to estimations from previous research indicating that more gateways are required. In addition, the deployment of multiple gateways decreased the loss of transmissions due to environmental and network factors. Given the complexity of our system, we received few colliding concurrent messages, which demonstrates a gap between the projected requirements of LoRaWAN systems and the actual requirements of real-world applications given sufficient gateways. We also contribute to the modelling of transmissions with our comparison of attenuation models derived from multiple methodologies. Across all models, we find that robust coverage in an indoor environment can be maintained by placing a gateway every 30 m and every 5 floors. Finally, we also investigate the application of DISNs for the passive sensing and visualisation of human presence using a Digital Twin (DT) and a Fused Twins (FT) representation in Augmented Reality (AR). A passive sensing approach allows us to gather relevant data on human use of a building while still preserving privacy via the aggregation process. Immersive in situ visualisations in FT allow for new interactions and new forms of participation. We conclude that DISNs are already technologically feasible today and basing them on Low Power Wide Area Network (LPWAN) offers intriguing possibilities to reduce energy consumption, maintenance cost, and bandwidth use while also enabling new forms of human-building interaction.     

Speculative incoherent cache protocols

Multiprocessing and multithreading are becoming ubiquitous even on single chips. With increasing cache sizes, coherence misses in such systems will account for a larger fraction of all cache misses. As communication latencies increase, this larger fraction of coherence misses will cause significant and increased performance losses. Tuning coherence protocols for specific communication patterns and applications can reduce communication latencies. However, these optimizations increase a protocol's design complexity, making the protocol difficult to verify. A competing approach requires parallel programmers to tune applications to work well with simpler protocols. Speculative execution has successfully improved performance in various scenarios. We propose a new type of load speculation, called coherence decoupling. Coherence decoupling is a microarchitectural mechanism that implements separate protocols for speculative use and for the eventual verification of values. The technique reduces the effect of long communication latencies while mitigating the burdens on the coherence protocol designer and the parallel programmer     

Constructing a secure hacking-resistant IoT U-healthcare environment

There has been an increasing demand of work that required high level of computing power in IoT or establishment of server in IoT environment due to development of computing power. Excessive diagnosis has recently been a significant issue in the field of medicine. Excessive diagnosis issue is expected to be significantly reduced if establishing the easily configurable IoT server, communication with medical devices, and communication among hospitals by transmitting medical results to users. With the advancement of hacking technology, many hackers are interested in medical information and medical infrastructure, and the Information Security Management System (ISMS) is expanding in Korea. A number of medical ISMS projects are discussed, based on ISO 27791 standards derived from ISO 27001 standards. Large hospitals in South Korea have a variety of platforms that misrepresent personal information, and various platforms deal with sensitive medical information, but small and medium-sized hospitals use platforms that are not considered legal considerations.In this paper, we intend to establish a legal information sharing platform, which is legally considered legally limited and is responsible for the safety of the medical information.In the IoT server with limited resources, light-weighted and user-friendly protocols are frequently utilized over those that derive traffic and consume much resource. Under these circumstances, this study is intended to suggest IoT network that medical devices are able to create ubiquitous environment for users by utilizing simple service discovery protocol as a protocol provided without imposing much burden on limited resources and highly secured extensible messaging and presence protocol.     

Unicast routing protocols for urban vehicular networks: review,taxonomy, and open research issues

Over the past few years, numerous traffic safety applications have been developed using vehicular ad hoc networks（VANETs）. These applications represent public interest and require network-wide dissemination techniques. On the other hand, certain non-safety applications do not require network-wide dissemination techniques.Such applications can be characterized by their individual interest between two vehicles that are geographically apart. In the existing literature, several proposals of unicast protocols exist that can be used for these non-safety applications. Among the proposals, unicast protocols for city scenarios are considered to be most challenging.This implies that in city scenarios unicast protocols show minimal persistence towards highly dynamic vehicular characteristics, including mobility, road structure, and physical environment. Unlike other studies, this review is motivated by the diversity of vehicular characteristics and difficulty of unicast protocol adaption in city scenarios.The review starts with the categorization of unicast protocols for city scenarios according to their requirement for a predefined unicast path. Then, properties of typical city roads are discussed, which helps to explore limitations in efficient unicast communication. Through an exhaustive literature review, we propose a thematic taxonomy based on different aspects of unicast protocol operation. It is followed by a review of selected unicast protocols for city scenarios that reveal their fundamental characteristics. Several significant parameters from the taxonomy are used to qualitatively compare the reviewed protocols. Qualitative comparison also includes critical investigation of distinct approaches taken by researchers in experimental protocol evaluation. As an outcome of this review, we point out open research issues in unicast routing.     

Extending Science Gateway Frameworks to Support Big Data Applications in the Cloud

Cloud computing offers massive scalability and elasticity required by many scientific and commercial applications. Combining the computational and data handling capabilities of clouds with parallel processing also has the potential to tackle Big Data problems efficiently. Science gateway frameworks and workflow systems enable application developers to implement complex applications and make these available for end-users via simple graphical user interfaces. The integration of such frameworks with Big Data processing tools on the cloud opens new opportunities for application developers. This paper investigates how workflow systems and science gateways can be extended with Big Data processing capabilities. A generic approach based on infrastructure aware workflows is suggested and a proof of concept is implemented based on the WS-PGRADE/gUSE science gateway framework and its integration with the Hadoop parallel data processing solution based on the MapReduce paradigm in the cloud. The provided analysis demonstrates that the methods described to integrate Big Data processing with workflows and science gateways work well in different cloud infrastructures and application scenarios, and can be used to create massively parallel applications for scientific analysis of Big Data.     

Java- and CORBA-based network management

Systems to manage distributed heterogeneous networks and services must often use off-the-shelf components and leverage legacy applications. Much of the telecommunications industry uses a network architecture based on CMIP (Common Management Information Protocol) to manage networks and services, while much of the Internet uses the SNMP (Simple Network Management Protocol). To provide distributed network management, the telecommunications industry must accommodate both, Nokia developed the Distributed Computing Platform prototype to support the creation, management, and invocation of distributed telecommunications services. Using CORBA as a base, DCP handles network management by adding managed-object models and protocols. It provides mechanisms that allow communication between CMIP-based objects and a gateway for SNMP-based systems. The prototype also allows users to access network information via Web browsers, CGI gateways, and Java or HTTP daemons. The Nokia engineers also discuss the lessons they learned about Java and CORBA integration