Network and common channel signalling aspects of dynamic satellite constellations

This paper discusses networking issues associated with the provision of L/S-band personal satellite communications. Both the UMTS and IMT-2000 third generation mobile communication concepts have identified the need for a satellite component as part of their overall structure. The work is mostly based on the ESA-developed medium altitude global satellite system (MAGSS-14).¹ It is, therefore, mainly relevant to MEO (medium earth orbit) constellations but most ideas can also be extended to LEO (low earth orbit) constellations. After examining user and service requirements the specific networking issues associated with personal satellite communications are reviewed. A network architecture is then proposed which takes these restrictions into account. Based on this network architecture, network signalling requirements, more specifically those relevant to network common control channels, are estimated.     

基于IPv6的无线传感器网络关键技术研究

基于IPv6技术的无线传感器网络是一门新兴的网络技术,人们对它的研究尚处于起步阶段。在此主要论述IPv6技术在无线传感器网组网应用,对使用无线与有线相结合的通信方法,通信协议和算法的研究,使得视频监控系统信号,通信系统信号以及检测系统信号在同一个通信平台上互不干涉的平稳的传输信息。就IPv6无线传感器网络与现有网络的互联互通方式,关键技术和算法等方面进行概述。     

无线传感器网络数据收集问题综述

数据收集问题研究外界用户如何通过无线传感器网络从监控区域收集感知数据。传感器节点通过自组织方式构成网络,数据收集问题就是寻找高效可靠的方式将感知数据通过多跳的方式传输给用户进行分析和处理。近几年对数据收集问题的研究非常广泛,主要包含减少数据收集过程中的数据传输量、数据收集协议和大规模网络数据收集调度等问题。从以上几方面对数据收集问题进行综述。     

Underwater acoustic sensor networks: research challenges

Underwater sensor nodes will find applications in oceanographic data collection, pollution monitoring, offshore exploration, disaster prevention, assisted navigation and tactical surveillance applications. Moreover, unmanned or autonomous underwater vehicles (UUVs, AUVs), equipped with sensors, will enable the exploration of natural undersea resources and gathering of scientific data in collaborative monitoring missions. Underwater acoustic networking is the enabling technology for these applications. Underwater networks consist of a variable number of sensors and vehicles that are deployed to perform collaborative monitoring tasks over a given area.In this paper, several fundamental key aspects of underwater acoustic communications are investigated. Different architectures for two-dimensional and three-dimensional underwater sensor networks are discussed, and the characteristics of the underwater channel are detailed. The main challenges for the development of efficient networking solutions posed by the underwater environment are detailed and a cross-layer approach to the integration of all communication functionalities is suggested. Furthermore, open research issues are discussed and possible solution approaches are outlined.     

High performance communication architecture for smart distribution power grid in developing nations

In a smart distribution power grid, cost efficient and reliable communication architecture plays a crucial role in achieving complete functionality. There are different sets of Quality of Services (QoS) requirements for different data packets transmitting inside the microgrid (a regionally limited smart distribution grid), making it challenging to derive optimal communication architecture. The objective of this research work is to determine the optimal communication technologies for each data packet based on its QoS requirement. In this paper, we have proposed an architecture for a smart distribution power grid with Cyber Physical System enabled microgrids, which accommodate almost all functional requirements of a smart distribution power grid. For easy transition towards optimal communication architecture, we have presented a six-tier communication topology, which is derived from the architecture for a smart distribution power grid. The optimization formulations for each packet structure presented in this paper minimize the overall cost and consider the QoS requirements for each packet. Based on the simulation results, we have made recommendations for optimal communication technologies for each packet and thereby developed a heterogeneous communication architecture for a microgrid.     

Pervasive, secure access to a hierarchical sensor-based healthcare monitoring architecture in wireless heterogeneous networks

This study presents a healthcare monitoring architecture coupled with wearable sensor systems and an environmental sensor network for monitoring elderly or chronic patients in their residence. The wearable sensor system, built into a fabric belt, consists of various medical sensors that collect a timely set of physiological health indicators transmitted via low energy wireless communication to mobile computing devices. Three application scenarios are implemented using the proposed network architecture. The group-based data collection and data transmission using the ad hoc mode promote outpatient healthcare services for only one medical staff member assigned to a set of patients. Adaptive security issues for data transmission are performed based on different wireless capabilities. This study also presents a monitoring application prototype for capturing sensor data from wireless sensor nodes. The implemented schemes were verified as performing efficiently and rapidly in the proposed network architecture.     

Network‐layer security for the Internet of Things using TinyOS and BLIP

The design of standard communications and security mechanisms for resource‐constrained sensing applications and devices may provide an important contribution for its integration with the Internet and consequently towards the realization of what we nowadays identify as the Internet of Things. This vision will only be realizable if appropriate security mechanisms are available, and in this context we target the design and experimental evaluation of security mechanisms for communications at the network‐layer with sensing devices (smart objects) using the standard IPv6 protocol. Our work proposes and evaluates the usage of new compressed security headers for the network layer with smart objects. We implement and evaluate what is, as far as we know, the first proposal of security at the network layer experimentally evaluated using the TinyOS operating system and its networking stack. As we verify in the course of our evaluation study, various scenarios employing network‐layer secure communications involving smart objects are feasible, particularly when security mechanisms are designed to benefit from cross‐layer interactions that allow the optimization of expensive cryptographic operations. Copyright © 2012 John Wiley & Sons, Ltd.     

Channel discovery algorithms for interference avoidance in smart grid communication networks: a survey

Smart grid technology has attracted a lot of attention in the communication and power engineering communities because of its high efficiency and environmental friendly power production and delivery. Smart grid communication networks act as not only a bridge between the end power users and the utility but also a backbone of the entire smart grid system. It is a challenging task to deploy smart grid communication networks because of interference‐intensive environment. The goal of this paper is to explore various issues on deployment of smart grid communication networks. The first half of this paper provides a survey on smart grid communication networks. The background of smart grid communication networks is introduced, and the IEEE 802.15.4g standard for smart utility networks is reviewed. In addition, the issues on network topology and routing protocols of smart utility networks are addressed, followed by the discussions on optimizing gateway deployment. Various methods for addressing coexistence issues in smart grid communication networks are presented. The second half of this paper is to propose a channel discovery algorithm exploiting the inherent CSMA/CA mechanism in the protocols. Because of the use of CSMA/CA mechanism and up‐to‐date channel status table, the proposed algorithm can quickly find an available channel for transmission when interferences occur. Copyright © 2014 John Wiley & Sons, Ltd.     

Design and Realization of an NFC-Driven Smart Home System to Support Intruder Detection and Social Network Integration

The Internet of thing (IoT) emerges as a possible solution to realize a smart life in the modern age. In this article, we design and realize a novel near field communication (NFC)-driven smart home system for IoT, which integrates the wireless sensor network (WSN), social networks, and the cloud computing. NFC technology provides a way for users to exchange information between them and the system by simply contacting. So, we propose to use NFC as the system drive in the architecture, such that users can intuitively interact with the system and deliver their intentions. Then, the corresponding service over the system will control or adjust the things at home to fit users' needs. Furthermore, the proposed system provides a platform for developers to easily and rapidly implement their smart home related services. In the system, WSN sensing and control, NFC communications and identification, user profile management and preference analysis, and social network integration are all provided as platform services. We will show how the system works for home automation, intruder detection, and social network sharing.     

基于加权队列的无线智能电网通信网采集数据流量调度算法

智能电网的关键技术之一是为电力数据采集提供一个高效、可靠、安全的双向通信系统。使用具有通信能力的先进电力计量设备(智能电表)组成无线mesh网络采集数据,存在应用层数据流量对网络通信性能的挑战,当大量数据流量突发时,与本地局域网关较近的智能电表将面临较大的通信压力,可能产生严重的数据拥塞。为此,该文基于多网关联合的思想,提出一个新的基于加权队列的流量调度算法以缓解拥塞。首先,对多网关联合网络进行分析,确定影响网络性能的主要因素。其次采用队列加权的方法,提出新的流量调度算法。最后进行网络仿真,相对其它算法,该文所提算法能够极大缓解数据突发时刻的系统拥塞,有效地降低时延,同时在系统各网关吞吐量之间取得良好的平衡,能够提高采集网络的通信性能。     

Delay-sensitive and multimedia communication in cognitive radio sensor networks

Multimedia and delay-sensitive data applications in cognitive radio sensor networks (CRSN) require efficient real-time communication and dynamic spectrum access (DSA) capabilities. This requirement poses emerging problems to be addressed in inherently resource-constrained sensor networks, and needs investigation of CRSN challenges with real-time communication requirements. In this paper, the main design challenges and principles for multimedia and delay-sensitive data transport in CRSN are introduced. The existing transport protocols and algorithms devised for cognitive radio ad hoc networks and wireless sensor networks (WSN) are explored from the perspective of CRSN paradigm. Specifically, the challenges for real-time transport in CRSN are investigated in different spectrum environments of smart grid, e.g., 500 kV substation, main power room and underground network transformer vaults. Open research issues for the realization of energy-efficient and real-time transport in CRSN are also presented. Overall, the performance evaluations provide valuable insights about real-time transport in CRSN and guide design decisions and trade-offs for CRSN applications in smart electric power grid.     

Density Based Fuzzy C Means Clustering to prolong Network Lifetime in Smart Grids

Wireless sensor networks (WSN's) are preferred for industrial applications due to progressive increase of sensor electronics. One such application is deployment of WSN's in smart grids. Smart Grid integrates information and communication techniques with electricity network. Smart grids utilize sophisticated control and monitoring devices for improving the efficiency of the grid. For energy efficient, low cost monitoring and control in smart grid WSN's is treated as a promising technology. Advanced Metering Infrastructure (AMI) is the key technology in the distribution networks of Smart Grid. The AMI is composed of various sensors for metering purpose. The meter data is also useful for the distribution operators to manage the demand response. The network involves smart meters, smart electric gas and water meters along with digital network management appliances for optimizing the electric network with real time data management. The smart sensors are limited in terms of battery, operational power and memory. These sensors communicate with the base station in restricted range. The communication between smart grid nodes and base station (sink) is multi-hop in nature. The communication takes place within limited range of communication so the security concerns that are involved in the network are to be handled by the routing protocols. So as to make the bidirectional communication efficient between the smart sensors and utility an effective routing scheme is required for these energy limited devices to handle the heavy network traffic in smart grids. Here energy efficient routing for WSN's in NAN networks to attain load balancing is proposed through density based Fuzzy C means clustering (DFCM). The obtained simulation results show that DFCM can provide a satisfactory performance for enhancing the network life span.

     

Inter-system communications/networking

Electric utilities require reliable data communications for power system control, operations, and maintenance. Utilities are among the largest users of data and, it has been said, the largest users of real-time data. In recent years, there has been an effort to apply the emerging technology of data communication networking to utility applications for real-time data exchange. Emphasis in this paper is placed on techniques for modeling communication requirements and planning the development of an inter-system communications network to support power applications. We will also review where the industry is today with regard to link installations and protocol development.     

一种面向智能电网数据采集的传感器聚合布局构造算法

智能电网中分布着大量的无线传感器用于监测智能电网设备和用户的运营状态信息,原始监测数据都采集到数据处理中心会给数据采集通信网络带来极大的数据流量压力。采用在数据采集过程中进行数据聚合的策略,将极大地缩减数据流量,降低通信网络的开销。因此聚合节点的选择以及聚合拓扑的构造成为智能电网数据采集的关键问题。该文提出一种基于层次聚类的异步分布式聚合布局构造算法。该算法首先按照层次聚类把所有节点按照距离的远近聚合构造出一棵采集树。随后计算出最佳分组数,按照该分组数进行分组。然后按照异步分布式策略进行最佳聚合节点的选择以及最佳传输拓扑的构造。仿真实验表明,该算法可以快速找到具有最小开销的数据聚合方式,提高智能电网数据采集网络的效率。     

A Novel Artificial Intelligence Based Timing Synchronization Scheme for Smart Grid Applications

The smart grid control applications necessitate real-time communication systems with time efficiency for real-time monitoring, measurement, and control. Time-efficient communication systems should have the ability to function in severe propagation conditions in smart grid applications. The data/packet communications need to be maintained by synchronized timing and reliability through equally considering the signal deterioration occurrences, which are propagation delay, phase errors and channel conditions. Phase synchronization plays a vital part in the digital smart grid to get precise and real-time control measurement information. IEEE C37.118 and IEC 61850 had implemented for the synchronization communication to measure as well as control the smart grid applications. Both IEEE C37.118 and IEC 61850 experienced a huge propagation and packet delays due to synchronization precision issues. Because of these delays and errors, measurement and monitoring of the smart grid application in real-time is not accurate. Therefore, it has been investigated that the time synchronization in real-time is a critical challenge in smart grid applications, and for this issue, other errors raised consequently. The existing communication systems are designed with the phasor measurement unit (PMU) along with communication protocol IEEE C37.118 and uses the GPS timestamps as the reference clock stamps. The absence of GPS increases the clock offsets, which surely can hamper the synchronization process and the full control measurement system that can be imprecise. Therefore, to reduce this clock offsets, a new algorithm is needed which may consider any alternative reference timestamps rather than GPS. The revolutionary Artificial Intelligence (AI) enables the industrial revolution to provide a significant performance to engineering solutions. Therefore, this article proposed the AI-based Synchronization scheme to mitigate smart grid timing issues. The backpropagation neural network is applied as the AI method that employs the timing estimations and error corrections for the precise performances. The novel AIFS scheme is considered the radio communication functionalities in order to connect the external timing server. The performance of the proposed AIFS scheme is evaluated using a MATLAB-based simulation approach. Simulation results show that the proposed scheme performs better than the existing system.

     

基于PTN MPLS-TP的通信网第二平面的设计

随着坚强智能电网建设和发展,传统SDH/MSTP通信传输网平台已不能够满足SG-ERP、省-市-县视频会商、输变电设备状态在线监测、应急通信、智能配网等对信息通信业务的IP化和高带宽需求,为此,需寻求一种新通信组网技术,既能满足IP业务承载、IP业务带宽突发性、高带宽等要求,又能实现网络级的OAM、QoS等。根据山东省地市数据承载网设计规划,提出基于PTN MPLS-TP的电力通信传输网第二平面的设计方案,供电力行业从业者参考。     

沙漠多节点宽带通信网络架构与关键技术

针对沙漠区域特殊环境下的资源能源受限的问题,提出了沙漠多节点宽带通信网络架构的构想,并梳理了其关键技术及解决途径。该网络采用两套体制和三层网络的架构,既可以满足低延迟的可靠性传输,又能达到宽带传输的目的。通过不同的通信体制和网络层级响应不同业务的传输,实现了沙漠特殊的无线传播环境和基础设施缺乏的条件下多节点宽带通信组网的目标,以解决沙漠区域信号盲区的通信问题。相应的通信组网技术可扩展应用到未来深空探测行星表面组网。     

Wireless multimedia sensor and actor networks for the next generation power grid

Electrical power grid is undergoing a major renovation, to meet the power quality and power availability demands of the 21st century. The new power grid, which is also called as the smart grid, aims to integrate the recent technological advancements in the Information and Communication Technology (ICT) field to the power engineering field. The present smart grid implementations focus on smart meter based utility-to-meter and utility-to-customer communications. Although these features provide significant improvements on the customer management side, in the following decades, grid management will be one of the major ICT-dominant fields. Recently, adoption of Wireless Sensor Networks (WSN) for the power grid is gaining wide attention from the industry and the academia. Scalar sensor measurements bring valuable insights, however they can provide limited set of information. In the next generation power grid, limited-sensing, Supervisory Control and Data Acquisition (SCADA) based, centrally controlled operational architecture will be replaced with wireless connected, low-cost, multimedia sensors combined with distributed decision-making and acting systems, working in coordination with a supervisory software tool. In this paper, we discuss the potential applications and the challenges of employing wireless multimedia sensor and actor network (WMSAN) for the smart grid.     

Next-generation wireless communications concepts and technologies

Next-generation wireless (NextG) involves the concept that the next generation of wireless communications will be a major move toward ubiquitous wireless communications systems and seamless high-quality wireless services. This article presents the concepts and technologies involved, including possible innovations in architectures, spectrum allocation, and utilization, in radio communications, networks, and services and applications. These include dynamic and adaptive systems and technologies that provide a new paradigm for spectrum assignment and management, smart resource management, dynamic and fast adaptive multilayer approaches, smart radio, and adaptive networking. Technologies involving adaptive and highly efficient modulation, coding, multiple access, media access, network organization, and networking that can provide ultraconnectivity at high data rates with effective QoS for Next Gare are also described     

Security and Privacy for Distributed Multimedia Sensor Networks

There is a critical need to provide privacy and security assurances for distributed multimedia sensor networking in applications including military surveillance and healthcare monitoring. Such guarantees enable the widespread adoption of such information systems, leading to large-scale societal benefit. To effectively address protection and reliability issues, secure communications and processing must be considered from system inception. Due to the emerging nature of broadband sensor systems, this provides fertile research ground for proposing more paradigm-shifting approaches. This paper discusses issues in designing for security and privacy in distributed multimedia sensor networks. We introduce the heterogeneous lightweight sensornets for trusted visual computing framework for distributed multimedia sensor networks. Protection issues within this architecture are analyzed, leading to the development of open research problems including secure routing in emerging free-space optical sensor networks and distributed privacy for vision-rich sensor networking. Proposed solutions to these problems are presented, demonstrating the necessary interaction among signal processing, networking, and cryptography.