Energy-Efficient Clustering Mechanism of Routing Protocol for Heterogeneous Wireless Sensor Network Based on Bamboo Forest Growth Optimizer

In wireless sensor networks (WSN), most sensor nodes are powered by batteries with limited power, meaning the quality of the network may deteriorate at any time. Therefore, to reduce the energy consumption of sensor nodes and extend the lifetime of the network, this study proposes a novel energy-efficient clustering mechanism of a routing protocol. First, a novel metaheuristic algorithm is proposed, based on differential equations of bamboo growth and the Gaussian mixture model, called the bamboo growth optimizer (BFGO). Second, based on the BFGO algorithm, a clustering mechanism of a routing protocol (BFGO-C) is proposed, in which the encoding method and fitness function are redesigned. It can maximize the energy efficiency and minimize the transmission distance. In addition, heterogeneous nodes are added to the WSN to distinguish tasks among nodes and extend the lifetime of the network. Finally, this paper compares the proposed BFGO-C with three classic clustering protocols. The results show that the protocol based on the BFGO-C can be successfully applied to the clustering routing protocol and can effectively reduce energy consumption and enhance network performance.     

延迟容忍移动传感器网络中基于最优距离的可靠节能传输策略

在延迟容忍移动传感器网络（Delay Tolerant Mobile Senor Networks，DTMSN）的数据传输过程中容易出现数据丢失及节点因能量耗尽而导致网络生存时间减少的问题.针对上述问题本文提出了基于最优距离的可靠节能传输策略，该传输策略利用距离与能量的关系解决了DTMSN中的三个重要问题：可靠性、能源效率、网络生存时间.首先，在链路质量保证下，引入了"可靠节能距离"和"可靠能量平衡距离"两个概念.此外，通过分析节点间距离、节点运动方向及节点当前剩余能量来确定节点的综合效用值，最后根据综合效用值的大小来路由消息.实验结果表明，该策略显著提高了消息的投递率及可靠性保证下传感器节点的能量利用率，延长了网络的生存时间.     

LED光源的应用探索

LED是英文Light Emitting Diode的简称,中文名称叫发光二极管。LED具有发光效率高、使用寿命长、不易破损、开关速度高、高可靠性诸多优点。LED光源在可见光范围的应用主要包括显示屏、交通信号、汽车工业、LED背光源、情景照明、情调照明。LED光源在红外光区域的应用主要体现在红外成像、遥感、遥测以及光纤通信方面。     

Secure coverage-preserving node scheduling scheme using energy prediction for wireless sensor networks

With the fast development of the micro-electro-mechanical systems(MEMS),wireless sensor networks(WSNs)have been extensively studied.Most of the studies focus on saving energy consumption because of restricted energy supply in WSNs.Cluster-based node scheduling scheme is commonly considered as one of the most energy-efficient approaches.However,it is not always so efficient especially when there exist hot spot and network attacks in WSNs.In this article,a secure coverage-preserved node scheduling scheme for WSNs based on energy prediction is proposed in an uneven deployment environment.The scheme is comprised of an uneven clustering algorithm based on arithmetic progression,a cover set partition algorithm based on trust and a node scheduling algorithm based on energy prediction.Simulation results show that network lifetime of the scheme is 350 rounds longer than that of other scheduling algorithms.Furthermore,the scheme can keep a high network coverage ratio during the network lifetime and achieve the designed objective which makes energy dissipation of most nodes in WSNs balanced.     

灵活光网络节能技术的分析与研究

为了减少灵活光网络中的能源消耗,以灵活光网络的关键技术为基础,对网络中能源消耗模型进行分析,从设备层、网络层以及网络全局三个角度对灵活光网络中节能技术进行分析与总结,最后在指出节能工作中多因素限制的条件下,对未来灵活光网络中能源效率的研究进行了展望.     

基于上行多用户大规模MIMO系统能效优化算法

针对上行多用户大规模多输入多输出（MIMO）系统,提出了基于能效优化的资源分配方法。所提方法采用迫零(ZF)接收,以最大化系统能效下界为准则,系统功率消耗考虑电路功率消耗和发射功率消耗2部分,通过联合调整基站端的发射天线数和用户的数据速率来优化能效函数。首先,根据目标函数的性质,证明全局最优速率分配和天线数的存在性和唯一性,然后,根据分数规划的性质,把原始的分数最优化问题转换成减式形式,进而提出一种新的迭代算法。仿真结果表明,所提算法以较少迭代次数取得了接近最优算法的性能。     

Survivable Routing Protocol for Green Wireless Mesh Networks Based on Energy Efficiency

This paper proposes a new Energyefficient Survivable Routing Protocol（ESRP）based on solar energy and wind mixed for power supply in green wireless mesh networks（WMNs）.The ESRP combines hop penalty strategy and flooding delaying strategy to improve the performances of traditional routing protocol.This paper uses QualNet to simulate and verify the performances of proposed ESRP.Compared with the traditional routing protocol,the simulation results show that the energy utilization of ESRP is more efficient by 13%.At the same time,ESRP is more load-balanced to postpone the appearance of the first energy depletion node and reduce the number of energy depletion nodes,and thus it effectively improves network survivability.     

自组织网MAC协议节能机制的研究与分析

为了解决自组织网节点供电不足的问题，在MAC接入方式的算法上进行改进是有必要的。从功率控制和能量管理两个方面，讨论自组织网几种典型的MAC层节能协议，分析这些算法减少功耗的能力以及在这些协议下自组织网络的吞吐量、时延等网络性能，并指出他们的优势和局限性，最后给出了结论。     

Energy-Efficient, Collision-Free Medium Access Control for Wireless Sensor Networks

The traffic-adaptive medium access protocol (TRAMA) is introduced for energy-efficient collision-free channel access in wireless sensor networks. TRAMA reduces energy consumption by ensuring that unicast and broadcast transmissions incur no collisions, and by allowing nodes to assume a low-power, idle state whenever they are not transmitting or receiving. TRAMA assumes that time is slotted and uses a distributed election scheme based on information about traffic at each node to determine which node can transmit at a particular time slot. Using traffic information, TRAMA avoids assigning time slots to nodes with no traffic to send, and also allows nodes to determine when they can switch off to idle mode and not listen to the channel. TRAMA is shown to be fair and correct, in that no idle node is an intended receiver and no receiver suffers collisions. An analytical model to quantify the performance of TRAMA is presented and the results are verified by simulation. The performance of TRAMA is evaluated through extensive simulations using both synthetic- as well as sensor-network scenarios. The results indicate that TRAMA outperforms contention-based protocols (CSMA, 802.11 and S-MAC) and also static scheduled-access protocols (NAMA) with significant energy savings. This work was supported in part by the NSF-NGI grant number ANI-9813724 and by the Jack Baskin Chair of Computer Engineering at UCSC. Venkatesh Rajendran received the B.E. degree in Electronics and Communication Engineering from the Anna University in 2001, and M.S. in Computer Engineering from the University of California, Santa Cruz (UCSC) in 2003. He is currently working towards his Ph.D at UCSC. He is a graduate student researcher at the Inter-networking Research Lab (INRG). His research interests are in wireless communication system design, energy-aware media access control protocols for wireless ad hoc networks, smart sensor networks, reliable multi-casting, wireless multi-carrier communications, digital signal processing, adaptive modulation, and smart antenna systems. Katia Obraczka received the B.S. and M.S. degrees in electrical and computer engineering from the Federal University of Rio de Janeiro, Brazil, and the M.S. and Ph.D. degrees in computer science from the University of Southern California (USC). She is an Assistant Professor of Computer Engineering at the University of California, Santa Cruz. Before joining UCSC, she held a research scientist position at USC's Information Sciences Institute and a research faculty appointment at USC's Computer Science Department. Her research interests include computer networks, more specifically, network protocol design and evaluation in wire-line as well as wireless (in particular, multi-hop ad hoc) networks, distributed systems, and Internet information systems. J.J. Garcia-Luna-Aceves received the M.S. and Ph.D. degrees in electrical engineering from the University of Hawaii, Honolulu, HI, in 1980 and 1983, respectively. He is the Baskin Professor of Computer Engineering at the University of California, Santa Cruz (UCSC). Dr. Garcia-Luna-Aceves directs the Computer Communication Research Group (CCRG), which is part of the Information Technologies Institute of the Baskin School of Engineering at UCSC. He has been a Visiting Professor at Sun Laboratories and a consultant on protocol design for Nokia. Prior to joining UCSC in 1993, he was a Center Director at SRI International (SRI) in Menlo Park, California. Dr. Garcia-Luna-Aceves has published a book and more than 250 refereed papers and three U.S patents, and has directed more than 18 Ph.D. theses at UCSC. He has been Program Co-Chair of ACM MobiHoc 2002 and ACM Mobicom 2000; Chair of the ACM SIG Multimedia; General Chair of ACM Multimedia '93 and ACM SIGCOMM '88; and Program Chair of IEEE MULTIMEDIA '92, ACM SIGCOMM '87, and ACM SIGCOMM '86. He has served in the IEEE Internet Technology Award Committee, the IEEE Richard W. Hamming Medal Committee, and the National Research Council Panel on Digitization and Communications Science of the Army Research Laboratory Technical Assessment Board. HE has been on the editorial boards of the IEEE/ACM Transactions on Networking, the Multimedia Systems Journal, and the Journal of High Speed Networks. He received the SRI International Exceptional-Achievement Award in 1985 and 1989, and is a senior member of the IEEE.     

无线传感器网络中基于PEGASIS协议的改进算法

 作为能量有效、基于链状结构的路由协议的典型代表,PEGASIS协议存在三个方面的不足,一是链的生成算法会导致相邻节点间产生长链;二是链头节点选取方法会导致节点间能量消耗不均衡;三是链头节点重选频率增加了通信开销.本文基于PEGASIS提出了一种新算法,新算法通过引入距离门限避免相邻节点间产生长链;通过综合考虑节点剩余能量以及节点到基站的距离来选取链头节点;通过降低链头节点重选频率来节省通信开销.分析和仿真结果表明,在未增加算法复杂度的情况下,新算法在平衡节点能耗和延长网络寿命方面比PEGASIS算法具有更优越的性能.