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1.
Kanodia Vikram Li Chengzhi Sabharwal Ashutosh Sadeghi Bahareh Knightly Edward 《Wireless Networks》2002,8(5):455-466
Providing Quality-of-Service in random access multi-hop wireless networks requires support from both medium access and packet scheduling algorithms. However, due to the distributed nature of ad hoc networks, nodes may not be able to determine the next packet that would be transmitted in a (hypothetical) centralized and ideal dynamic priority scheduler. In this paper, we develop two mechanisms for QoS communication in multi-hop wireless networks. First, we devise distributed priority scheduling, a technique that piggybacks the priority tag of a node's head-of-line packet onto handshake and data packets; e.g., RTS/DATA packets in IEEE 802.11. By monitoring transmitted packets, each node maintains a scheduling table which is used to assess the node's priority level relative to other nodes. We then incorporate this scheduling table into existing IEEE 802.11 priority backoff schemes to approximate the idealized schedule. Second, we observe that congestion, link errors, and the random nature of medium access prohibit an exact realization of the ideal schedule. Consequently, we devise a scheduling scheme termed multi-hop coordination so that downstream nodes can increase a packet's relative priority to make up for excessive delays incurred upstream. We next develop a simple analytical model to quantitatively explore these two mechanisms. In the former case, we study the impact of the probability of overhearing another packet's priority index on the scheme's ability to achieve the ideal schedule. In the latter case, we explore the role of multi-hop coordination in increasing the probability that a packet satisfies its end-to-end QoS target. Finally, we perform a set of ns-2 simulations to study the scheme's performance under more realistic conditions. 相似文献
2.
Efficient routing and medium access control (MAC) are very important for Mobile Ad hoc Networks (MANETs). Most existing routing
and MAC protocols consider homogeneous ad hoc networks, in which all nodes are modeled as the same, i.e., they have the same
communication capabilities and characteristics. Although a homogeneous network model is simple and easy to analyze, it misses
important characteristics of many realistic MANETs such as military battlefield ad hoc networks. In addition, a homogeneous
ad hoc network suffers from poor performance and scalability. In many ad hoc networks, multiple types of nodes do co-exist;
and some nodes have larger transmission power, higher transmission data rate, and better processing capability, are more reliable
and robust than other nodes. Hence, a hybrid network model is more realistic and provides many advantages for designing better
routing and MAC protocols. In this paper, we present a new routing protocol called Hybrid Routing, which is specifically designed
for hybrid MANETs. In addition, a novel MAC protocol is jointly designed for hybrid MANETs. Extensive simulations demonstrate
that the proposed routing MAC protocols have very good performance.
相似文献
Dapeng Wu (Corresponding author)Email: URL: http://www.wu.ece.ufl.edu |
3.
Existing multi-channel Medium Access Control (MAC) protocols have been demonstrated to significantly increase wireless network performance compared to single channel MAC protocols. Traditionally, the channelization structure in IEEE 802.11 based wireless networks is pre-configured, and the entire available spectrum is divided into subchannels and equal channel widths. In contrast, this paper presents a Traffic-Aware Channelization MAC (TAC-MAC) protocol for wireless ad hoc networks, where each node is equipped with a single half duplex transceiver. TAC-MAC works in a distributed, fine-grai-ned manner, which dynamically divides variable-width subchannels and allocates subchannel width based on the Orthogonal Frequency Division Multiplexing (OFDM) technique according to the traffic demands of nodes. Simulations show that the TAC-MAC can significantly improve network throughput and reduce packet delay compared with both fixed-width multi-channel MAC and single channel 802.11 protocols, which illustrates a new paradigm for high-efficient multi-channel MAC design in wireless ad hoc networks. 相似文献
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介绍了无线传感器网络的概念、几种主要的无线传感器网络协议,尤其是MAC层协议的研究情况,给出了一些比较经典的无线传感器网络MAC协议的思想。 相似文献
6.
Michael B. Pursley Harlan B. Russell Jeffrey S. Wysocarski 《International Journal of Wireless Information Networks》2004,11(3):147-159
The use of adaptive-transmission protocols in wireless, store-and-forward, packet communication networks may result in large differences in the energy requirements of the alternative paths that are available to the routing protocol. Routing metrics can provide quantitative measures of the quality and energy efficiency of the paths from the source to the destination. Such measures are required if the routing protocol is to take advantage of the potential energy savings that are made possible by an adaptive-transmission protocol. An energy-efficient protocol suite for routing and adaptive transmission in frequency-hop wireless networks is described and evaluated, several routing metrics are compared, and tradeoffs among energy efficiency, delay, and packet success probability are investigated. 相似文献
7.
提出了一种分布式高效节能的无线传感器网络数据收集和路由协议HEEDC.此协议中传感器节点根据自身状态(综合考虑剩余能量、节点密度等因素计算得出的代价因子)自主的竞争簇首,同时为减少簇首节点的能量开销,簇首之间通过多跳方式将各个簇内收集到的数据发送给特定簇首节点,并由此簇首节点将整个网络收集的数据发送给汇聚节点.仿真实验表明,HEEDC协议比起现有的几种重要路由协议(如LEACH、PEGASIS等),能提供更加有效的能量使用效率,延长无线传感器网络的生存周期.因此,使用HEEDC协议的无线传感器网络具有更好的使用性,其监测结果具有更高的可靠性. 相似文献
8.
Sensor networks have a wide range of potential, practical and useful applications. However, there are issues that need to
be addressed for efficient operation of sensor network systems in real applications. Energy saving is one critical issue for
sensor networks since most sensors are equipped with non-rechargeable batteries that have limited lifetime. To extend the
lifetime of a sensor network, one common approach is to dynamically schedule sensors' work/sleep cycles (or duty cycles).
Moreover, in cluster-based networks, cluster heads are usually selected in a way that minimizes the total energy consumption
and they may rotate among the sensors to balance energy consumption. In general, these energy-efficient scheduling mechanisms
(also called topology configuration mechanisms) need to satisfy certain application requirements while saving energy. In this
paper, we provide a survey on energy-efficient scheduling mechanisms in sensor networks that have different design requirements
than those in traditional wireless networks. We classify these mechanisms based on their design assumptions and design objectives. Different mechanisms may make different assumptions about their sensors including detection model, sensing area, transmission
range, failure model, time synchronization, and the ability to obtain location and distance information. They may also have
different assumptions about network structure and sensor deployment strategy. Furthermore, while all the mechanisms have a
common design objective to maximize network lifetime, they may also have different objectives determined by their target applications.
A preliminary was presented in BROADNETS 2006 [29] 相似文献
9.
Ad hoc networks formed without the aid of any established infrastructure are typically multi-hop networks. Location dependent
contention and hidden terminal problem make priority scheduling in multi-hop networks significantly different from that in
wireless LANs. Most of the prior work related to priority scheduling addresses issues in wireless LANs. In this paper, priority
scheduling in multi-hop networks is discussed. We propose a scheme using two narrow-band busy tone signals to ensure medium
access for high priority source stations. The simulation results demonstrate the effectiveness of the proposed scheme.
Xue Yang received the B.E. degree and the M.S. degree from University of Electronic Science and Technology of China. She is currently
a Ph.D. candidate at University of Illinois at Urbana-Champaign (UIUC). She is awarded Vodafone-U.S. Foundation Graduate Fellowship
from 2003 to 2005. Her current research is in the areas of wireless networking and mobile computing, with the focus on medium
access control, quality of service and topology control. Her research advisor is Prof. Nitin Vaidya at UIUC. For more information,
please visit
Nitin H. Vaidya received the PhD degree from the University of Massachusetts at Amherst. He is presently an Associate Professor of Electrical
and Computer Engineering at the University of Illinois at Urbana-Champaign (UIUC). He has held visiting positions at Microsoft
Research, Sun Microsystems and the Indian Institute of Technology-Bombay. His current research is in the areas of wireless
networking and mobile computing. His research has been funded by various agencies, including the National Science Foundation,
DARPA, BBN Technologies, Microsoft Research, and Sun Microsystems. Nitin Vaidya is a recipient of a CAREER award from the
National Science Foundation. Nitin has served on the program committees of several conferences and workshops, and served as
program co-chair for the 2003 ACM MobiCom. He has served as editor for several journals, and presently serves as Editor-in-Chief
for IEEE Transactions on Mobile Computing, and as editor-in-chief of ACM SIGMOBILE periodical MC2R. He is a senior member
of IEEE and a member of the ACM. For more information, please visit 相似文献
10.
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. 相似文献
11.
文章研究了多信道资源分配算法,并对其5个重要过程:获取节点请求列表过程、请求分类缓冲过程、请求队列截取过程、资源分配过程、节点使用分配结果过程进行了探讨。文章认为在算法中可以考虑增加请求信息的内容以完善分配机制,加入自适应的优先级预留比例调整机制,添加和完善更高效地分配时隙、信道二维资源。 相似文献
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针对无线传感器网络中存在的热区问题,采用非均匀部署方案,并在此基础上提出基于能量预测的无线传感器网络节点覆盖调度算法。并对算法进行了仿真实验和性能分析。结果表明该算法可以延长的网络生命周期并在较长的时间里保持较高的网络覆盖率,能够达到网络内大多数节点能耗均衡的设计目标。 相似文献
16.
媒体访问控制(MAC)协议是无线传感器网络的关键协议之一,它对无线传感网络的运行和性能具有重要的影响.针对基于簇的TDMA机制存在问题,文中提出了一个动态节能的DE-MAC协议,该协议能够根据簇成员节点数目和通信负载动态地分配成员节点的时隙,减少节点的空闲侦听时间.仿真结果表明,DE-MAC协议能够有效地提高信道的利用率和网络能量有效性. 相似文献
17.
Lightweight Deployment-Aware Scheduling for Wireless Sensor Networks 总被引:14,自引:0,他引:14
Wireless sensor networks consist of a large number of tiny sensors that have only limited energy supply. One of the major
challenges in constructing such networks is to maintain long network lifetime as well as sufficient sensing areas. To achieve
this goal, a broadly-used method is to turn off redundant sensors. In this paper, the problem of estimating redundant sensing
areas among neighbouring wireless sensors is analysed. We present simple methods to estimate the degree of redundancy without
the knowledge of location or directional information. We also provide tight upper and lower bounds on the probability of complete
redundancy and on the average partial redundancy. With random sensor deployment, our analysis shows that partial redundancy
is more realistic for real applications, as complete redundancy is expensive, requiring up to 11 neighbouring sensors to provide
a 90 percent chance of complete redundancy. Based on the analysis, we propose a scalable Lightweight Deployment-Aware Scheduling
(LDAS) algorithm, which turns off redundant sensors without using accurate location information. Simulation study demonstrates
that the LDAS algorithm can reduce network energy consumption and provide desired QoS requirement effectively.
This research was partially supported by Natural Sciences and Engineering Research Council of Canada.
Kui Wu received his Ph.D. in Computing Science from the University of Alberta, Canada, in 2002. He joined the Department of Computer
Science at the University of Victoria, Canada in the same year and is currently an Assistant Professor there. His research
interests include mobile and wireless networks, network performance evaluation, and network security.
Yong Gao received his Master's degree and Ph.D. degree in computer science from University of Alberta, Canada, in 2000 and 2005 respectively.
He is currently with the Irving K. Barber School of Arts and Sciences, UBC Okanagan, Canada. His research interests include
search algorithms and AI, communication networks, and computational biology.
Yang Xiao worked at Micro Linear as an MAC (Medium Access Control) architect involving the IEEE 802.11 standard enhancement work before
he joined Department of Computer Science at The University of Memphis in 2002. Dr. Xiao is an IEEE Senior member. He was a
voting member of IEEE 802.11 Working Group from 2001 to 2004. He currently serves as Editor-in-Chief for International Journal
of Security and Networks (IJSN) and for International Journal of Sensor Networks (IJSNet). He serves as an associate editor
or on editorial boards for the following refereed journals: (Wiley) International Journal of Communication Systems, (Wiley)
Wireless Communications and Mobile Computing (WCMC), EURASIP Journal on Wireless Communications and Networking, and International
Journal of Wireless and Mobile Computing. He serves as five lead/sole guest editor for five journal special issues. He serves
as a referee/reviewer for many funding agencies, as well as a panelist for NSF. His research interests are Security/ Reliable
Communications, Medium Access Control, Mobility/Location/Paging Managements, Cache Access and Replacement Policies, Quality
of Service, Energy Efficiency, and Routing in wireless networks and mobile computing. 相似文献
18.
To improve the capacity of wireless ad hoc networks by exploiting multiple available channels, we propose a distributed channel
assignment protocol that is based on a cross-layer approach. By combining channel assignment with routing protocols, the proposed
channel assignment protocol is shown to require fewer channels and exhibit lower communication, computation, and storage complexity
than existing channel assignment schemes. A multi-channel MAC (MC-MAC) protocol that works with the proposed channel assignment
protocol is also presented. We prove the correctness of the proposed channel assignment protocol. In addition, through a performance
study, we show that the proposed protocol can substantially increase throughput and reduce delay in wireless ad hoc networks,
compared to the IEEE 802.11 MAC protocol and an existing multi-channel scheme.
相似文献
Shiwen MaoEmail: |
19.
YU Yi-fan YIN Chang-chuan YUE Guang-xin School of Telecommunications Engineering Beijing University of Posts Telecommunications Beijing P.R. China 《中国邮电高校学报(英文版)》2005,12(2)
1IntroductionIn Ad hoc networks , the nodes share the wirelesschannel under the control of media access control proto-col . Currently,there are two types of MAC protocolsproposedfor Ad hoc networks . The first is hand-shak-ing protocol such as IEEE 802 .11 MAC protocol[1 ~4]and MACAW[5], which controls the access procedureby exchanging the control packets among the activenodes . The secondis busy-tone protocol that introducesadditional busy tone signal to control the medium ac-cess . S… 相似文献
20.
Wieselthier Jeffrey E. Nguyen Gam D. Ephremides Anthony 《Mobile Networks and Applications》2001,6(3):251-263
In this paper we address the problem of multicasting in ad hoc wireless networks from the viewpoint of energy efficiency. We discuss the impact of the wireless medium on the multicasting problem and the fundamental trade-offs that arise. We propose and evaluate several algorithms for defining multicast trees for session (or connection-oriented) traffic when transceiver resources are limited. The algorithms select the relay nodes and the corresponding transmission power levels, and achieve different degrees of scalability and performance. We demonstrate that the incorporation of energy considerations into multicast algorithms can, indeed, result in improved energy efficiency. 相似文献