一种无线传感器网络的访问控制协议

传感器网络中的节点存在由于能量耗尽或恶意攻击而丧失作用的威胁,因此需要新节点的加入.利用Bloom Filter技术,提出了一种访问控制协议.本协议不仅便于实现新节点、旧节点的双向认证和密钥协商,而且便于实现节点的加入与撤消.通过性能分析和安全性分析说明了该协议的有效性.     

A Delay-Aware Congestion Control Protocol for Wireless Sensor Networks

In wireless sensor networks, congestion leads to buffer overflowing, and increases delay. The tradi-tional solutions use rate adjustment to mitigate congestion, thus increasing the delay. A Delay-aware congestion con-trol protocol (DACC) was presented to mitigate congestion and decrease delay. In order to improve the accuracy of the existing congestion detection model which is based on the buffer occupancy of a single node, DACC presents a new model considering both the real-time buffer occupancy and the average transmission time of packets. DACC uses the untapped bits in the IEEE 802.11 Distributed coordination function (DCF) frames header to carry congestion infor-mation. During the congestion alleviation period, DACC presents a channel occupancy mechanism which is based on the real-time buffer occupancy for the purpose of decreas-ing delay and preventing packet loss. Simulation results indicate that in terms of delay, packet delivery ratio, col-lision and buffer load, DACC has comparative advantages than those of 802.11 DCF, Priority-based congestion con-trol protocol (PCCP) and Decoupling congestion control and fairness (DCCF).     

面向WLAN的无线传感器网络网关设备及其接入机制

网关是实现无线传感器网络与其他基础网络（如移动通信网、电信网等）互联互通的重要设备。文章设计并实现了一种基于CC2420芯片的网关,实现了与传感器网络的通信,并利用无线网卡模块实现了网关设备与无线局域网的连接,克服了网关硬件设备布置的局限性,扩大了网关设备和无线传感器网络的应用范围。     

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.     

分布式系统中的安全访问控制

本文主要讨论如何利用现代密码技术实现分布式系统中的安全访问控制。     

面向云存储的安全密文访问控制方案

存储在云端服务器中的敏感数据的保密和安全访问是云存储安全研究的重要内容.针对真实的云存储环境中云服务提供商不可信的情况,采用基于属性的加密算法,提出了一种安全、高效、细粒度的云存储密文访问控制方案.与现有方案相比,该方案在用户撤销时,通过引入广播加密技术,使得撤销用户即使和云服务提供商共谋,也不能对私钥进行更新,保证了数据的安全性;方案将大部分密文重加密和用户私钥更新工作转移给云服务提供商执行,在保证安全性的前提下,降低了数据属主的计算代价;另外该方案还可支持多用户的同时撤销.最后分析了方案的安全性和计算复杂性,并测试了用户撤销时的运行效率.     

水下无线传感器网络中一种安全定位算法

提出一种基于阵列传输结构的无线传感器网络安全定位算法（USA）。该算法主要解决水下无线传感器网络（UWSN）面临的一些安全威胁问题。以提高无线传感器网络安全性,特别是位置信息的安全性为设计目标。利用节点协作形成的阵列作为天线阵列进行相互通信,在不增加额外硬件成本的同时,还获得阵列天线给无线传感器网络带来的优势,如减小多径效应、提高接收端的信噪比、增加系统容量等。USA算法基于这种阵列结构使网络得到很高安全特性,特别是,对Wormhole攻击具有非常好的抵御性能。仿真实验证明该算法的有效性。     

Jitter Detection for Synchronization Control in Wireless Multimedia Sensor Networks

Collaborative in-network processing operations in Wireless multimedia sensor networks （WMSNs） often require effective synchronization control. Extensive researches in the traditional networks mainly focus on the synchronization control with the buffer management in the receiver. However, for WMSNs, the chaotic transport channel and low bandwidth introduce serious jitter. Jitter degrades the timing relationship among packets in a single media stream and between packets from different media streams and, hence, creates multimedia synchronization problems. Moreover, too much jitter will also degrade the performance of the streaming buffer. By only employing the buffer management scheme in the receiver, we can hardly satisfy the synchronization requirement of the in-network processing. In this study, we propose an active jitter detection mechanism for the synchronization control in WMSNs. This mechanism will improve the quality of service in multimedia networking by discarding the jitter-corrupted packets immediately and balancing the delay and jitter actively. We implement the proposed scheme in the practical WMSNs platform. The experiment results show that our scheme can reduce the average packet jitter effectively and improve the synchronization controlling performance significantly.     

无线传感器网络体系结构研究

对无线传感器网络的体系结构进行了深入研究,从无线传感器网络的物理体系结构、软件体系结构、通信体系结构三个层面进行了分析,分析结果对于无线传感器网络的设计具有参考价值。     

工业无线层次传感器网络的动态TDMA算法

Industrial wireless sensor networks adopt a hierarchical structure with large numbers of sensors and routers. Time Division Multiple Access (TDMA) is regarded as an efficient method to reduce the probability of confliction. In the intra-cluster part, the ran-dom color selection method is effective in reducing the retry times in an application. In the inter-cluster part, a quick assign algorithm and a dynamic maximum link algorithm are proposed to meet the quick networking or minimum frame size requirements. In the sim-ulation, the dynamic maximum link algorithm produces higher reductions in the frame length than the quick assign algorithm. When the number of routers is 140, the total number of time slots is reduced by 25%. However, the first algorithm needs more control messages, and the average difference in the number of control messages is 3 410. Consequently, the dynamic maximum link algorithm is utilized for adjusting the link schedule to the minimum delay with a relatively high throughput rate, and the quick assign algo-rithm is utilized for speeding up the network-ing process.     

一种新的主动节点资源访问控制策略

较传统网络而言,主动网络的复杂性引起了更加严峻的资源安全问题,特别在主动节点方面.文章详细分析了主动节点资源访问的研究现状和存在的问题,设计了主动节点资源访问安全体系,提出了一种新的主动节点资源访问控制机制.并提出利用权能对资源访问控制策略进行描述,动态维护.采用基于角色的访问控制方法实现对用户的管理.     

WMSN的半依赖基站密钥管理方案

由于传统的WSN密钥管理方案,并没有考虑到无线多媒体节点的特殊性,文章提出半依赖基站密钥管理方案。该方案将密钥的产生和分发放在多媒体节点上,而sink节点采用延时认证方法负责所有节点的认证。通过分析后,该密钥管理方案符合安全性要求,并且具有较高的连通性,保证多媒体传感器网络安全高效运行。     

WLAN Mesh网络安全接入技术研究

WLANMesh网络是当前主流的新型动态自组织网络。为了在适应多跳和自组织特性的条件下提供可靠安全能力,IEEE802．11S标准草案提出了全新的安全框架-Mesh安全关联（MSA）。将结合标准草案介绍MSA架构,包括新的密钥体系以及建立部署该密钥体系使用的协议的交互,并对协议安全特性进行简要安全分析。最后针对架构过于复杂的弱点提出一个试验性Kerberos风格的简化方案。     

M－DQCA：可调信道访问光波网介质访问控制协议

本文提出了一种可调信道访问光波网以及适合于该网的介质访问控制协议Ｍ－ＤＱＣＡ，利用波分复用技术将双总线光波网分成多个并行信道，用一个信道专门传输等时业务和请求信息，使网络管理得到简化；利用时隙重用技术，提高了网络的吞吐量；拥塞控制方法与多跳网相比简单得多，各用户只需根据本站缓存的情况来控制输入业务的流量。计算机仿真表明，Ｍ－ＤＱＣＡ光波网具有很好的性能。     

Sensitivity and Coding of Opportunistic ALOHA in Sensor Networks with Mobile Access

We consider a distributed medium access protocol, Opportunistic ALOHA, for reachback in sensor networks with mobile access points (AP). We briefly discuss some properties of the protocol, like throughput and transmission control for an orthogonal CDMA physical layer. We then consider the incorporation of necessary side information like location into the transmission control and numerically demonstrate the loss in throughput in the absence of such information. Through simulations, we discuss the robustness and sensitivity of the protocol under various modeling errors and propose strategies to allow for errors in estimation of some parameters without reduction in the throughput. For networks, where the sensors are allowed to collaborate, we consider three coding schemes for reliable transmission: spreading code independent, spreading code dependent transmission and coding across sensors. These schemes are compared in terms of achievable rates and random coding error exponents. The coding across sensors scheme has comparable achievable rates to the spreading code dependent scheme, but requires the additional transmission of sensor ID. However, the scheme does not require the mobile AP to send data through the beacon unlike the other two schemes. The use of these coding schemes to overcome sensitivity is demonstrated through simulations. Parvathinathan Venkitasubramaniam was born in India in 1981. He received his B.Tech. degree from the department of Electrical Engineering, Indian Institute of Technology, Madras in 2002. He joined the School of Electrical and Computer Engineering, Cornell University, Ithaca, NY, in 2002 and he is working toward his Ph.D. degree. He is a recipient of the 2004 Leonard G. Abraham Award (with S. Adireddy and L. Tong) from the IEEE Communications Society. His research interests include random-access protocols,sensor networks, and information theory. Srihari Adireddy was born in India in 1977. He received the B.Tech. degree from the Department of Electrical Engineering, Indian Institute of Technology, Madras, and M.S. and Ph. D. degrees from the School of Electrical and Computer Engineering, Cornell University, Ithaca, NY in 2001 and 2003 respectively. Currently, he is working at Silicon Laboratories, Austin, TX. He is a recipient of the 2004 Leonard G. Abraham Award (with P. Venkitasubramaniam and L. Tong) from the IEEE Communications Society. His research interests include signal processing, information theory, and random-access protocols. Lang Tong received the B.E. degree from Tsinghua University, Beijing, China, in 1985, and M.S. and Ph.D. degrees in electrical engineering in 1987 and 1990, respectively, from the University of Notre Dame, Notre Dame, Indiana. He was a Postdoctoral Research Affiliate at the Information Systems Laboratory, Stanford University in 1991. Currently, he is a Professor in the School of Electrical and Computer Engineering, Cornell University, Ithaca, New York. Dr. Tong received Young Investigator Award rom the Office of Naval Research in 1996, and the Outstanding Young Author Award from the IEEE Circuits and Systems Society in 1991, the 2004 IEEE Signal Processing Society Best Paper Award (with M. Dong), the 2004 Leonard G. Abraham Prize Paper Award from the IEEE Communications Society (with P. Venkitasubramaniam and S. Adireddy). His areas of interest include statistical signal processing, adaptive receiver design for communication systems, signal processing for communication networks, and information theory.     

无线传感器网络在医疗中的应用

首先简介无线传感器网络的体系结构以及无线传感器网络在医疗中的应用情况,接着对无线传感器网络医疗监护系统的体系结构以及监护节点的设计进行阐述,最后,阐述无线传感器网络应用到医疗监护时存在的挑战。     

无线传感器网络拓扑控制策略研究

节能设计是无线传感器网络的首要设计目标,拓扑控制是实现该目标的重要技术之一,其主要目标是在保证网络连通和覆盖的前提下剔除不必要的通信链路,降低节点能耗和减少通信干扰,为MAC协议和路由协议的顺利执行提供基础。文中对传感器网络拓扑控制策略进行了的分析。最后针对目前传感器节点成本仍然很高这一特点,通过仿真得出了在节点随机配置的情况下,保证网络连通和覆盖所需的至少节点数目。并通过仿真分析证明了方案的可行性。