基于跨层网络编码感知的无线传感器网络节能路由算法研究

编码感知路由可以发现路由中的网络编码机会,减少数据传输次数,提高网络吞吐量,是近年来路由算法研究的一个热点.当前编码感知路由存在编码条件失效、未考虑节点能量的问题,不适合直接应用于无线传感器网络.本文提出基于跨层网络编码感知的无线传感器网络节能路由算法CAER (Cross layer coding Aware Energy efficient Routing).提出并证明了修正后的网络编码条件,以解决编码条件失效问题.基于跨层思想,将网络编码感知机制与拓扑控制、覆盖控制结合,挖掘潜在编码机会.提出综合考虑节点编码机会、节点能量的跨层综合路由度量CCRM (Cross layer Coding aware Routing Metric).仿真结果表明,相比现有编码感知路由,CAER能够提高网络编码感知准确性,增加网络编码机会数量5%~15%,延长网络生存时间8%~12%.     

基于网络编码的无线路由技术研究进展

网络编码是近年来通信领域所取得的重大进展之一,其核心思想是网络节点对于接收的分组不是采取的传统的存储-转发的简单路由方式,而是存储-编码处理-转发的方式。网络编码已被证明是改善无线网络性能特别是吞吐量性能方面的下一代关键技术之一,特别适合战场环境下广播和组播信息的高效传输。本文综述了近年来基于网络编码的无线路由技术的相关研究进展,分析了现有研究的局限性与不足,并对下一步研究方向进行了展望。     

WSN中能量有效路由协议的研究

由于WSN中节点能量的限制,路由协议成为当前研究热点之一。WSN的路由协议必须能平衡网络的能量消耗,延长网络寿命。近年来提出了大量能量有效的路由协议。在深入调查这些协议的基础上,将他们分为4大类:基于网络结构、通信模型、拓扑结构以及可靠机制。在每大类下又基于不同的策略细分了这些协议,进而更有规律地去阐述这些路由协议的原理和他们的优缺点。     

Energy Efficient Adaptation of Multicast Protocols in Power Controlled Wireless Ad Hoc Networks

In this paper a methodology for adapting existing wireless ad hoc network protocols to power controlled networks is presented. Wireless nodes are assumed to have transmission power control with m discrete levels, and a clustering scheme is used in the adaptation to be energy efficient. Clusters are formed among the nodes in a distributed self-organized manner so that each node is a member of some cluster and within a cluster, each node can reach any other node with an appropriate power level. Each cluster has a designated head node which acts as forwarding agent for its members and these head nodes form a supernode topology. We adapt an ad hoc network multicast protocol by executing it on this supernode topology. Multicast data will move from the sender to its cluster head, then along the supernode topology according to the results of the chosen multicast protocol, and finally from the cluster head to receivers within their clusters. At every step, nodes use an appropriate power level j, 1jm, to reach all the intended recipients. For more balanced way of depleting energy in the network, nodes take turn to become cluster heads. We applied our technique to ODMRP and the experiment shows significant energy reduction.     

无线Mesh网络路由协议研究

无线Mesh网络WMN（wireless mesh networks）是一种新型的无线网络,它融合了无线局域网（WLAN）和Ad Hoc网络的优势,成为宽带接入的一种有效手段。首先介绍了无线Mesh网的网络结构和特点．并在此基础上讨论了无线Mesh网络对路由协议的要求。无线Mesh网络的路由算法是Mesh领域的研究难点,通过分析比较4种针对WMN的路由协议,总结了现有的路由协议的优缺点,并对今后的研究方向做出了展望。     

An Efficient Multicast Routing Protocol in Wireless Mobile Networks

Providing multicast service to mobile hosts in wireless mobile networking environments is difficult due to frequent changes of mobile host location and group membership. If a conventional multicast routing protocol is used in wireless mobile networks, several problems may be experienced since existing multicast routing protocols assume static hosts when they construct the multicast delivery tree. To overcome the problems, several multicast routing protocols for mobile hosts have been proposed. Although the protocols solve several problems inherent in multicast routing proposals for static hosts, they still have problems such as non-optimal delivery path, datagram duplication, overheads resulting from frequent reconstruction of a multicast tree, etc. In this paper, we summarize these problems of multicast routing protocols and propose an efficient multicast routing protocol based on IEFT mobile IP in wireless mobile networks. The proposed protocol introduces a multicast agent, where a mobile host receives a tunneled multicast datagram from a multicast agent located in a network close to it or directly from the multicast router in the current network. While receiving a tunneled multicast datagram from a remote multicast agent, the local multicast agent may start multicast join process, which makes the multicast delivery route optimal. The proposed protocol reduces data delivery path length and decreases the amount of duplicate copies of multicast datagrams. We examined and compared the performance of the proposed protocol and existing protocols by simulation under various environments and we got an improved performance over the existing proposals.     

Low Power Downlink MAC Protocols for Infrastructure Wireless Sensor Networks

This paper addresses low power medium access control (MAC) protocols for the downlink channel of infrastructure wireless sensor networks. Access points are assumed to be energy unconstrained. The trade-off between the power consumption of the sensor nodes and the transmission delay is analyzed, focusing on low traffic. We describe WiseMAC (Wireless Sensor MAC), a new protocol for the downlink of infrastructure wireless sensor networks. Another original contribution is the presentation and analysis of PTIP (Periodic Terminal Initiated Polling). Here, polling is used in the reversed direction as compared to common polling protocols. WiseMAC and PTIP are compared with PSM (Power Save Mode), the power save protocol used in both the IEEE 802.11 and IEEE 802.15.4 ZigBee standards. Analytical expressions are derived for the power consumption and the transmission delay for each protocol, as a function of the wake-up period. It is shown that WiseMAC provides, with low bit rate radio transceivers, a significantly lower power consumption than PSM. Although less energy efficient than WiseMAC and PSM, it is shown that PTIP can, thanks to its implementation simplicity, become attractive for applications tolerating large transmission delays.Amre El-Hoiydi received the electrical engineer degree from the Swiss Federal Institute of Technology in Zurich (ETHZ), Switzerland, in 1994. In 1995, he was a teaching assistant at the Swiss Federal Institute of Technology in Lausanne (EPFL), working on mobility management for low earth orbit mobile satellite communication systems. In 1996, he joined CSEM (Neuchâtel, Switzerland). Since then, he has been working on several research and development projects dealing with various aspects of wireless communications. In the ACTS RAINBOW and FRAMES projects, he was involved with the network and air interface aspects of 3rd generation cellular systems. In the ESPRIT INFOGATE and IST OPENROUTER projects, he worked on electronic design and embedded programming of Linux based wireless LAN gateways. His current research focus is low power communication protocols for wireless sensor networks.Jean-Dominique Decotignie is head of the real-time and networking group at the Swiss Center for Electronics and Microsystems (CSEM) in Neuchâtel. He is professor at the School of Computer and Communication Sciences of EPFL (Swiss Federal Institute of Technology in Lausanne) and teaches real-time systems as well as hardware and software design. From 1977 to 1982, he has worked at EPFL and the University of Tokyo in the area of optical communications. In 1983, he joined the Industrial Computer Engineering Lab. at EPFL where he became Assistant Professor in 1992. From 1989 to 1992, he has been the head of an interdisciplinary project on Computer Integrated Manufacturing at EPFL. Since January 1997, he is with CSEM. His current research interests include industrial and real-time local area networks, distributed control systems and software engineering for real-time systems as well as real-time wireless networks.     

无线传感器网络MAC协议研究

本文首先从应用需求和业务特性两方面分析了无线传感器网络MAC协议设计面临的挑战.然后,结合现有典型协议,对无线传感器网络MAC协议的研究现状和趋势、节能策略及协议其他特点进行了分析与总结.最后,探讨了无线传感器网络MAC协议的待研究问题.     

无线传感器网络可靠数据传输协议的研究

数据的可靠传输是一个成熟的网络应该给用户所提供的基本服务。在能量受限和带宽受限的无线传感器网络(wireless sensor networks)中,同样需要可靠的数据传输。首先分析了TCP应用于无线传感器网络的不足,然后介绍了目前可靠数据传输协议的主要研究进展和关键技术,重点阐述了PSFQ、ESRT和RMST协议的应用场景和基本原理,分析了不同协议各自的优缺点,最后展望了可靠数据传输的研究方向和发展前景。     

Energy-Scalable Protocols for Battery-Operated MicroSensor Networks

In wireless sensor networks, the goal is to gather information from a large number of sensor nodes and communicate the information to the end-user, all under the constraint of limited energy resources. Network protocols minimize energy by using localized communication and control and by exploiting computation/communication tradeoffs. In addition, data fusion algorithms such as beamforming aggregate data from multiple sources to reduce data redundancy and enhance signal-to-noise ratios, thus further reducing the required communications. We have developed a sensor network system that uses a localized clustering protocol and beamforming data fusion to enable energy-efficient collaboration. We compare the performance of two beamforming algorithms, the Maximum Power and the Least Mean Squares (LMS) beamforming algorithms, using the StrongARM SA-1100 processor. Results show that the LMS algorithm requires less than one-fifth the energy required by the Maximum Power beamforming algorithm with only a 3 dB loss in performance, thus showing that the LMS algorithm is better suited for energy-constrained systems. We explore the energy-scalability of the LMS algorithm, and we propose an energy-quality scalable architecture that incorporates techniques such as variable filter length, variable voltage supply and variable adaptation time.     

Performance Evaluation of Routing Protocols for Ad Hoc Wireless Networks

A mobile ad hoc network is a collection of autonomous mobile nodes that communicate with each other over wireless links. Such networks are expected to play an increasingly important role in future civilian and military settings, being useful for providing communication support where no fixed infrastructure exists or the deployment of a fixed infrastructure is not economically profitable and movement of communicating parties is possible. However, since there is no stationary infrastructure such as base stations, mobile hosts need to operate as routers in order to maintain the information about the network connectivity. Therefore, a number of routing protocols have been proposed for ad hoc wireless networks. In this paper, we study and compare the performance of the following routing protocols AODV, PAODV (preemptive AODV), CBRP, DSR, and DSDV. A variety of workload and scenarios, as characterized by mobility, load and size of the ad hoc network were simulated. Our results indicate that despite its improvement in reducing route request packets, CBRP has a higher overhead than DSR because of its periodic hello messages while AODV's end-to-end packet delay is the shortest when compared to DSR and CBRP. PAODV has shown little improvements over AODV.     

Performance Evaluation of Polling Protocols for Data Transmission on Wireless Communication Networks

The growing interest in mobile computing and communication devices leads to the necessity of wireless broadband network. Data transmission over such networks requires suitable error control schemes to guarantee high data reliability as well as efficient bandwidth utilization.In this paper we propose an accurate yet simple analytical approach to evaluate the performance of wireless networks using gated and exhaustive polling protocols combined with the Stop and Wait (SW) or Go Back N (GBN) ARQ schemes [Bertsekas and Gallager, 2]. Moreover, simulation results concerning the performance of polling protocols combined with the Selective Repeat (SR) ARQ scheme are also shown for comparison purposes.Protocol performance is estimated under very general assumptions, such as: AWGN or fading channels, arbitrary value of the round trip delay and arbitrary distribution of the traffic load (i.e., both symmetric or asymmetric system have been considered).     

Localized Algorithms for Energy Efficient Topology in Wireless Ad Hoc Networks

Topology control in wireless ad hoc networks is to select a subgraph of the communication graph (when all nodes use their maximum transmission range) with some properties for energy conservation. In this paper, we propose two novel localized topology control methods for homogeneous wireless ad hoc networks. Our first method constructs a structure with the following attractive properties: power efficient, bounded node degree, and planar. Its power stretch factor is at most , and each node only has to maintain at most neighbors where the integer is an adjustable parameter, and β is a real constant between 2 and 5 depending on the wireless transmission environment. It can be constructed and maintained locally and dynamically. Moreover, by assuming that the node ID and its position can be represented in bits each for a wireless network of n nodes, we show that the structure can be constructed using at most 24n messages, where each message is bits. Our second method improves the degree bound to k, relaxes the theoretical power spanning ratio to , where is an adjustable parameter, and keeps all other properties. We show that the second structure can be constructed using at most 3n messages, where each message has size of bits. We also experimentally evaluate the performance of these new energy efficient network topologies. The theoretical results are corroborated by the simulations: these structures are more efficient in practice, compared with other known structures used in wireless ad hoc networks and are easier to construct. In addition, the power assignment based on our new structures shows low energy cost and small interference at each wireless node. The work of Xiang-Yang Li is partially supported by NSFCCR-0311174. Wen-Zhan Song received Ph.D. from Illinois Institute of Technology in 2005, BS and MS from Nanjing University of Science and Technology in 1997 and 2000. He is currently an assistant professor in Washington State University. His current research interest is mainly focus on network protocol and algorithm design, especially in wireless networks, sensor networks and Peer-to-Peer networks. He is a member of the IEEE. Yu Wang received the Ph.D. degree in computer science from Illinois Institute of Technology in 2004, the BEng degree and the MEng degree in computer science from Tsinghua University, China, in 1998 and 2000. He has been an assistant professor of computer science at the Univeristy of North Carolina at Charlotte since 2004. His current research interests include wireless networks, mobile computing, algorithm design, and artificial intelligence. He is a member of the ACM, IEEE, and IEEE Communication Society. Xiang-Yang Li has been an Assistant Professor of Computer Science at the Illinois Institute of Technology since 2000. He hold MS (2000) and PhD (2001) degree at Computer Science from University of Illinois at Urbana-Champaign. He received his Bachelor degree at Computer Science and Bachelor degree at Business Management from Tsinghua University, P.R. China in 1995. His research interests span the computational geometry, wireless ad hoc networks, game theory, cryptography and network security. He is a Member of the ACM, IEEE, and IEEE Communication Society. Ophir Frieder is the IITRI Professor of Computer Science at the Illinois Institute of Technology. His research interests span the general area of distributed information systems. He is a Member of ACM and a Fellow of the IEEE.     

多跳无线网络MAC协议的研究进展

该文简要介绍了多跳无线网络的结构及其MAC协议的分类,简述了近几年来国内外对多跳无线网络MAC协议研究的几个新进展。这些协议均有各自的特点,适用于不同种类的无线网络。最后展望了多跳无线网络MAC协议的发展前景。     

Maximizing Network Lifetime of Broadcasting Over Wireless Stationary Ad Hoc Networks

We investigate the problem of extending the network lifetime of a single broadcast session over wireless stationary ad hoc networks where the hosts are not mobile. We define the network lifetime as the time from network initialization to the first node failure due to battery depletion. We provide through graph theoretic approaches a polynomial-time globally optimal solution, a variant of the minimum spanning tree (MST), to the problem of maximizing the static network lifetime. We make use of this solution to develop a periodic tree update strategy for effective load balancing and show that a significant gain in network lifetime over the optimal static network lifetime can be achieved. We provide extensive comparative simulation studies on parameters such as update interval and control overhead and investigate their impact on the network lifetime. The simulation results are also compared with an upper bound to the network lifetime. A preliminary version of this paper appeared in IEEE ICC 2003 [35]. This research was funded in part by NSF grant ANI-0093187, ONR award #: N00014-04-1-0479 and Collaborative Technology Alliance (CTA) from ARL under DAAD19-01-2-0011. All statements and opinions are that of the authors and do not represent any position of the U.S government Intae Kang received his B.S. degree in physics from Seoul National University, Seoul, Korea and M.S. degree in electrical engineering from the Johns Hopkins University, Baltimore, MD. He is currently working toward the Ph.D. degree in the Department of Electrical Engineering at the University of Washington, Seattle, WA. His current research interests are in the area of ad hoc and sensor networks. In particular, he is interested in energy efficient routing, topology control, medium access control, mobility management, and modeling and performance analysis of network protocols using directional/smart antennas. Radha Poovendran has been an assistant professor at the Electrical Engineering Department of the University of Washington at Seattle since September 2000. He received his Ph.D. in Electrical Engineering from the University of Maryland, College Park in 1999. His research interests are in the areas of applied cryptography for multiuser environment, wireless networking, and applications of Information Theory to security. He is a recipient of Faculty Early Career Award from the National Science Foundation (2001), Young Investigator Award from the Army Research Office (2002), Young Investigator Award from the Office of Naval Research (2004), and the 2004 Presidential Early Career Award for Scientists and Engineers, for his research contributions in the areas of wired and wireless multiuser security. He is also a co-recipient of the 2002 Outstanding Teaching as well as the Outstanding Advisor Awards from the Department of Electrical Engineering of the University of Washington.     

校园网中的无线组网方案

文中首先介绍现存的无线网络技术，计论适用佼园网环境的无线组网方法。然后给出校园内局域网间、校园网间及校园网与ＣＥＲＮＥＴ地区网络中心之间的无线互连实例。最后介绍移动计算网络的概念，指出今后校园网中移动计算网络的实现方法。     

多跳无线网路由协议研究进展

移动计算和无线通信的飞速发展为无线网络的应用开辟了美好前景．作为一种没有基础设施的无线网络，多跳无线网在战场、紧急救援等场合具有得天独厚的优势。多跳无线网路由协议的主要作用是监控网络拓扑变化、交换路由信息、产生和维护路由，它是目前的研究热点之一。本介绍了该领域的研究进展，首先叙述多跳无线网的8个特点及其对路由协议的7个要求．然后描述21种路由协议的原理并比较它们的特性，最后阐述了10个研究方向。     

Probabilistic Power Management for Wireless Ad Hoc Networks

Extending system lifetime by effectively managing power on participating nodes is critical in wireless ad hoc networks. Recent work has shown that, by appropriately powering off nodes, energy may be significantly saved up to a factor of two, especially when node density is high. Such approaches rely on the selection of a virtual backbone (i.e., a connected dominating set) of the topology to forward ongoing traffic, coupled with algorithms to manually and periodically recompute such a backbone for load balancing purposes. The common drawback of such schemes is the need to involve periodic message exchanges and to make additional restrictive assumptions. This paper presents Odds¹, an integrated set of energy-efficient and fully distributed algorithms for power management in wireless ad hoc networks. Odds build on the observation that explicit and periodic re-computation of the backbone topology is costly with respect to its additional bandwidth overhead, especially when nodes are densely populated or highly mobile. Building on a fully probabilistic approach, Odds seek to make a minimum overhead, perfectly balanced, and fully localized decision on each node with respect to when and how long it needs to enter standby mode to conserve energy. Such a decision does not rely on periodic message broadcasts in the local neighborhood, so that Odds are scalable as node density increases. Detailed mathematical analysis, discussions and simulation results have shown that Odds are indeed able to achieve our objectives while operating in a wide range of density and traffic loads.Zongpeng Li received his B.Engr. in 1999, from Department of Computer Science and Technology, Tsinghua University, China, and his M.S. degree in 2001 from the Department of Computer Science, University of Toronto. He is currently working towards his Ph.D. degree in the Department of Electrical and Computer Engineering, University of Toronto. His research interests include algorithm design and analysis for both wireless and wireline networks.Baochun Li received his B.Engr. degree in 1995 from Department of Computer Science and Technology, Tsinghua University, China, and his M.S. and Ph.D. degrees in 1997 and 2000 from the Department of Computer Science, University of Illinois at Urbana-Champaign. Since 2000, he has been with the Department of Electrical and Computer Engineering at the University of Toronto, where he is an Assistant Professor. In 2000, he was the recipient of the IEEE Communications Society Leonard G. Abraham Award in the Field of Communications Systems. His research interests include network-level and application-level Quality of Service provisioning, application-layer overlay networks, wireless ad hoc networks, and mobile computing.     

基于高能效无线接入网的绿色无线通信关键技术研究

目前,无线通信网络的巨大能耗及其产生的环境问题已经成为通信业乃至全社会关注的焦点。绿色无线通信旨在提高无线通信网络能源使用效率、显著降低网络能耗,受到学术界及业界的普遍关注,业已成为全球通信行业的研究热点。本文从无线通信网络能耗出发,分析了无线通信网络的能耗组成,明确了无线接入网是全网能耗的重点优化目标,并进一步从器件级、链路级和网络级3个层面,全面剖析了基于无线接入网的绿色无线通信基本原理、方法以及通信行业广泛关注的核心技术,力图建立高能效无线接入网络,显著优化无线通信网络能耗。