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Anchor‐free distance estimation: A new approach to distance estimation for multihop ad hoc wireless networks 下载免费PDF全文
Stathis Mavridopoulos Petros Nicopolitidis Georgios Papadimitriou 《International Journal of Communication Systems》2018,31(13)
In ad hoc wireless networks, devices that normally cannot directly communicate route their messages through intermediate nodes. The number of those nodes is called hop count, a useful metric in estimating the distance between 2 nodes. Current methods usually depend on special nodes, called anchors, that need accurate localization information, in order to calculate an estimate for the average distance traversed per hop. The drawback of this approach is that anchor nodes increase the overall cost and complexity of the system. To address this problem, this letter proposes a novel, anchor node–free algorithm that can achieve a useful estimate for actual distance between 2 nodes, by analytically finding an estimate for the average maximum distance traveled per hop and multiplying with the hop count. The only requirement is the a priori knowledge of the networks' node density and the node range. The performance of our method is compared with a recent anchor node–based method and is shown to yield similar location estimation accuracy, despite the fact that it does not use anchor nodes. 相似文献
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一种Ad—hoc密钥维护优化方案 总被引:2,自引:2,他引:0
Ad-hoc网络节点之间的无线连接越多,网络通信跳数相对越少,但网络需要的密钥量越大,加重了密钥维护的负担,因此在通信跳数可接受的情况下应该尽量减少密钥量。定义了网络付出的代价,用来描述通信跳数和密钥量。以网络付出的代价最小为原则,设计了一种简单的密钥维护优化方案。将方案应用于一个Ad-hoc场景,推算结果表明该方案对密钥维护的优化是有效的。 相似文献
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1 Introduction A wireless multihop network or Ad-hoc network [1, 2] is a network of independent mobile hosts without any network infrastructure or connection to base stations. In many application areas, however, Internet connectivity and access to service… 相似文献
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Jang-Ping Sheu Chih-Min Chao Wei-Kai Hu Ching-Wen Sun 《Wireless Personal Communications》2007,43(2):185-200
In multihop wireless ad hoc networks, it is important that all mobile hosts are synchronized. Synchronization is necessary
for power management and for frequency hopping spread spectrum (FHSS) operations. IEEE 802.11 standards specify a clock synchronization
protocol but this protocol suffers from the scalability problem due to its inefficiency contention mechanism. In this paper,
we propose an automatic self-time-correcting procedure (ASP) to achieve clock synchronization in a multihop environment. Our
ASP has two features. First, a faster host has higher priority to send its timing information out than a slower one. Second,
after collecting enough timing information, a slower host can synchronize to the faster one by self-correcting its timer periodically
(which makes it becoming a faster host). Simulation results show that our ASP decreases 60% the average maximum clock drift
as compared to the IEEE 802.11 and reduces 99% the number of asynchronism in a large-scale multihop wireless ad hoc networks. 相似文献
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基于多信道预约可冲突避免的多址接入协议 总被引:3,自引:0,他引:3
本文为多跳分布多无线网络提出了一套灵活而有效的自适应获取冲突避免(AACA)的多址接入协议。在该协议中,各节点竞争公共信道,利用RTS/CTS对话形式来预约各业务信道,成功预约后的分组传输不会受到其他节点的干扰。它使用任意确定数目信道,以异步方式工作,并且使得各节点利用半双工无线电台就可以灵活、简便地实现资源预约。分析和比较结果说明,所提出的多信道预约协议可以有效地解决隐藏终端、暴露终端以及侵入终端的问题。 相似文献
7.
Michael Gerharz Christian de Waal Peter Martini Paul James 《Telecommunication Systems》2005,28(3-4):317-331
In this article, we introduce a simple distributed algorithm that assigns appropriate individual transmission powers to devices in a wireless ad hoc network. In contrast to many other proposed algorithms, it does without special hardware. It requires only local neighbourhood information and therefore avoids flooding information throughout the network. Finally, the cooperative nature of the algorithm avoids that devices cause excessive interference by using unnecessarily high transmission powers. By means of simulation, we show that the topologies created by this algorithm without any global knowledge are as effective as topologies resulting from a good choice of a common transmission power (which would require global knowledge) in terms of the achievable throughput.
This work was supported in part by the German Federal Ministry of Education and Research (BMBF) as part of the IPonAir project. 相似文献
8.
This paper puts forward a novel cognitive cross-layer design algorithms for multihop wireless networks optimization across physical,mediam access control(MAC),network and transport layers.As is well known,the conventional layered-protocol architecture can not provide optimal performance for wireless networks,and cross-layer design is becoming increasingly important for improving the performance of wireless networks.In this study,we formulate a specific network utility maximization(NUM)problem that we believe is appropriate for multihop wireless networks.By using the dual algorithm,the NUM problem has been optimal decomposed and solved with a novel distributed cross-layer design algorithm from physical to transport layers.Our solution enjoys the benefits of cross-layer optimization while maintaining the simplicity and modularity of the traditional layered architecture.The proposed cross-layer design can guarantee the end-to-end goals of data flows while fully utilizing network resources.Computer simulations have evaluated an enhanced performance of the proposed algorithm at both average source rate and network throughput.Meanwhile,the proposed algorithm has low implementation complexity for practical reality. 相似文献
9.
本文对密度波分复用光波网的关键技术作了技术,对单跳网介质访问控制协议及多跳网的虚拓扑结构作了评述。介绍了几种典型的试验系统,并指出了有关研究方向和尚待解决的问题。 相似文献
10.
Theodoros A. Tsiftsis 《International Journal of Communication Systems》2008,21(5):559-565
We present closed‐form bounds for the performance of wireless multihop communications systems with cooperative diversity over Nakagami‐m fading channels. The end‐to‐end signal‐to‐noise ratio is formulated and upper bounded by using the inequality between harmonic and geometric means of positive random variables. Closed‐form expression is derived for the moment‐generating function and is used to obtain lower bounds for the average error probability. Numerical results are compared with computer simulations showing the tightness of the proposed bounds. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献