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1.
《Computer Networks》2002,38(2):121-135
An ad hoc network is a multi-hop wireless network of mobile nodes without the intervention of fixed infrastructure. Limited bandwidth and mobility require that ad hoc routing protocols be robust, simple, and energy conserving. This paper proposes a new ad hoc multicast routing protocol called neighbor-supporting multicast protocol (NSMP). NSMP adopts a mesh structure to enhance resilience against mobility. And NSMP utilizes node locality to reduce the overhead of route maintenance. NSMP also attempts to improve route efficiency and reduce data transmissions. Our simulation results show that NSMP delivers packets efficiently while substantially reducing control overhead in various environments.  相似文献   

2.
This paper discusses some aspects related to Wireless Sensor Networks over the IEEE 802.15.4 standard, and proposes, for the very first time, a mesh network topology with geographic routing integrated to the open Freescale protocol (SMAC - Simple Medium Access Control). For this is proposed the SMAC routing protocol. Before this work the SMAC protocol was suitable to perform one hop communications only. However, with the developed mechanisms, it is possible to use multi-hop communication. Performance results from the implemented protocol are presented and analyzed in order to define important requirements for wireless sensor networks, such as robustness, self-healing property and low latency.  相似文献   

3.
The use of ad hoc networking technologies is emerging as a viable and cost-effective solution to extend the range of traditional wireless local area networks (WLANs). In these networks, mobile client traffic reaches the access points through multi-hop wireless paths that are established by using an ad hoc routing protocol. However, several technical challenges have to be faced in order to construct such an extended WLAN. For instance, traditional autoconfiguration protocols commonly used in infrastructure-based WLANs, such as DHCP or Zeroconf, are not directly applicable in multi-hop wireless networks. To address this problem, in this paper we propose extensions to DHCP to enable the dynamic allocation of globally routable IPv4 addresses to mobile stations in hybrid ad hoc networks, which transparently integrate conventional wired technologies with wireless ad hoc networking technologies. Some of the attractive features of our solution are its ability to cope with node mobility, the introduction of negligible protocol overheads, and the use of legacy DHCP servers. We have implemented a prototype of our scheme, and tested its functionalities considering various topology layouts, network loads and mobility conditions. The experimental results show that our solution ensures short address configuration delays and low protocol overheads.  相似文献   

4.
A system procedure is proposed for a multi-robot rescue system that performs real-time exploration over disaster areas. Real-time exploration means that every robot exploring the area always has a communication path to human operators standing by at a base station and that the communication path is configured by ad hoc wireless networking. Real-time exploration is essential in multi-robot systems for USAR (urban search and rescue) because operators must communicate with every robot to support the victim detection process and ad hoc networking is suitable to configure a communication path among obstacles. The proposed system procedure consists of the autonomous classification of robots into search and relay types and behavior algorithms for each class of robot. Search robots explore the areas and relay robots act as relay terminals between search robots and the base station. The rule of the classification and the behavior algorithm refer to the forwarding table of each robot constructed for ad hoc networking. The table construction is based on DSDV (destination-sequenced distance vector) routing that informs each robot of its topological position in the network and other essentials. Computer simulations are executed with a specific exploration strategy of search robots. The results show that a multi-robot rescue system can perform real-time exploration with the proposed system procedure and reduce exploration time in comparison with the case where the proposed scheme is not adopted.  相似文献   

5.
胡荣  杨春  何军  李奇 《计算机工程》2010,36(16):71-73
针对传感器网络聚类间能耗负载不均衡和传统拓扑方案连通冗余度过高等问题,提出一种基于模拟退火算法的聚类间的多跳路由方案。在聚类首领至基站的路由选择上,改变传统的一跳路由至多跳路由,基于首领节点的度约束和能耗代价,为每一个首领节点均衡地选择下一跳路由,避免“能量热点”问题。实验结果表明,与LEACH、EECS协议相比,该方案所获拓扑能均衡各聚类的能耗负载,降低网络整体功耗,延长传感器网络的生命周期。  相似文献   

6.
移动Ad hoc网络是由一组移动终端组成的无线多跳自治系统,具有无中心、自组织、多跳路由、动态拓扑结构等特点。尽管有带宽受限等缺点,但无线Ad hoc网络具备灵活机动、组网迅速的优势,在军事通信、民用通信和各种临时通信中具有广阔的应用前景。近来其路由技术、QoS、安全性问题,尤其是路由协议的安全成为研究的热点。介绍了针对其路由协议的攻击,重点分析比较了典型的移动Ad hoc网络安全路由协议,最后指出下一步研究的方向。  相似文献   

7.
无线Adhoc网络拓扑结构的频繁变化使得如何在多变的拓扑结构中快速找路,以及路径失效后的快速重新找路成为无线Adhoc网络中路由协议研究的主要目标之一。随着无线Adhoc网络带宽的增加,无线Adhoc网络中的视频业务逐渐变得现实起来,因此也成为了研究的重点,但是视频业务与普通业务比起来,在分组到达的延迟上要求很严,因此以上两个方面无疑是一对矛盾。论文重点讨论了在动态源路由协议(DynamicSourceRouting,以下简称DSR)基础上,视频业务所带来的诸多问题,结合DSR路由模块的试验床提出一种解决方法,并把改进后的DSR协议与原始的DSR协议在一些性能参数上作了分析与比较。  相似文献   

8.
王镇  刘学军 《传感技术学报》2011,24(11):1625-1631
蚁群算法的随机自适应性使得它很适合应用于无线传感器网络( WSN)环境中,所以本文针对WSN中的数据拥塞、传输延迟、能量消耗等问题,提出了一种基于蚁群算法的QoS路由协议.协议将如何搜索最佳路径问题抽象为组合规划问题,根据最小费用流规则定义了高带宽和低时延路径的判决条件,利用蚁群优化算法,寻找到不同目标函数的路径,达到...  相似文献   

9.
A multi-robot system can be highly beneficial for exploration, which is a core robotics task. Application domains include, for example, surveillance, reconnaissance, planetary exploration or rescue missions. When using a team of robots, the overall performance can be much faster and more robust. In this article, an approach to multi-robot exploration is presented that takes the constraints of wireless networking into account. An algorithm is introduced based on a population that samples the possible moves of all robots and a utility to select the best one in each time step. Results from two scenarios are presented. In the first one, a team of robots explores its environment while permanently maintaining an ad hoc network structure with each other as well as a base station at a fixed location. In the second one, the robots move freely as a pack while maintaining communication with each other.  相似文献   

10.
禹辉  黄本雄 《计算机工程》2002,28(9):136-138
在对多跳无线网路由协议的研究现状进行分析的基础上,选择了专用按需距离向量路由(AODV)协议作为抗毁式多跳无线网络由协议,协议的实现充分考虑了无线信道的有限带宽和移动性,提高了网络性能和抗毁性。此无线路由协议适用于特殊环境下多跳无线网的抗毁性要求,通过对专用按需距离向量跳由(AODV)协议的分析,得出了有指导意义的结论。  相似文献   

11.
在多跳认知无线电网络中,组播的信息通常要经由多个中间节点的转发才能到达最终的目的节点。现有的研究中已经有很多的组播路由协议,然而这些协议都是基于传统无线网络的,并不适合新型的认知无线电网络。本文解决的的问题是:在多跳无线网络中,给定一个具有QoS要求的组播请求,如何建立组播路由以及对路径节点进行传输调度,使得在满足QoS要求下整个传输过程的带宽消耗最小。本文提出了一个分布式的组播路由协议来解决该问题,该协议不仅实现了路由过程的建立,同时还完成了对节点传输过程的合理调度。实验结果证明本文的传输调度策略能有效地减少网络的带宽消耗,同时增加组播请求响应的成功率。  相似文献   

12.
Wireless sensor networks (WSNs) are a kind of communication networks having independent sensor nodes that form multi-hop ad hoc network to transfer data. In the past few years, various transport control protocols in wireless sensor networks (WSNs) have been developed and proposed in the literature. In this paper, we have analyzed pump slowly, fetch quickly (PSFQ) protocol and presented an improved transport layer protocol for wireless sensor networks. The improved protocol has been analyzed based on various factors such as average latency and average error tolerance and it is found that the proposed protocol is better than PSFQ in terms of these factors.  相似文献   

13.
Bluetooth is one of the most widespread technologies for personal area networks that allow portable devices to form multi-hop Bluetooth ad hoc networks, so called scatternets. Routing is one of the challenges in scatternets because of its impact on the performance of the network. It should focus on reducing the power consumption in the network because most of the nodes are battery-operated portable devices. In this paper, we propose a routing protocol for Bluetooth scatternets that customizes the Ad hoc On-Demand Distance Vector (AODV) routing protocol by making it power-aware and suitable for scatternets. It enhances the AODV flooding mechanism by excluding all non-bridge slaves from taking apart in the AODV route discovery process. In addition, it improves the AODV route discovery phase by considering the hop count, the predicated node’s power, and the average traffic intensity for each node as metrics for best route selection. By removing HELLO packets, our protocol reduces the control packets overhead and the power consumption in network devices. Simulation results show that the proposed protocol achieved considerable improvements over other enhanced AODV protocols by increasing the data delivery ratio by 10.78%, reducing the average end-to-end delay by 8.11%, and reducing the average energy consumption by 7.92%.  相似文献   

14.
针对无线传感器网络中的“热区”问题,提出了一种新的低能耗的非均匀分簇路由协议——LEUC.该协议中,采用分布武与集中式相结合的方式依据节点的剩余能量与相对圆环中心线的位置选择簇首,成簇时综合考虑簇首能量与信号强度,簇内根据簇的大小采用单跳或者多跳传输数据,簇间构建多跳动态路由.仿真结果表明:LEUC协议可以较好地解决“...  相似文献   

15.
将多协议标签交换(MPLS)技术与无线自组网组播机制相结合可以把MPLS在分组转发以及支持服务质量、流量工程等方面的技术优势引入到无线自组网组播路由协议设计中,具此提出了一种基于MPLS技术的组播协议设计方案——标签交换转发组播协议(Label-Switching Forwarding multicast routing protocol,以下简称LSF组播协议)。  相似文献   

16.
Bluetooth is a new technology for low-cost, low-power, and short-range wireless communication. By constructing a piconet, Bluetooth device establishes link and communicates with other device in a master–slave manner. Relay is a Bluetooth device that joins two or more piconets and forwards data from one piconet to another, providing multi-hop (or inter-piconet) communication services. In a Bluetooth scatternet, the number of relays and the degree of each relay are factors that significantly affect the performance of entire network. Unnecessary relays raise the difficulty of scheduling, leading to frequent packet loss. Relay switching among several piconets in turns also creates guard time overhead and increases the transmission delay. This study presents an effective protocol that can dynamically adjust the network topology by reducing the unnecessary relays. An efficient scatternet environment thus can be constructed with characteristics of connected, high bandwidth utilization and low maintenance cost. Additionally, a routing protocol is developed to reduce the path length and generate two disjoint routes for any pair of source and destination devices located in different piconets. Experimental results demonstrate that the proposed protocols perform well in terms of route length, bandwidth consumption, and transmission delay.  相似文献   

17.
无线传感器网络(WSN)是由大量部署在监测区域内的微型传感器节点通过无线通信方式组成的一个多跳、自组织的网络。分布式的环境感知能力和简单灵活的部署方式,使得WSN成为影响人们日常生活的重要因素;并且随着微电子技术和通信技术的不断发展,WSN已被广泛应用于国防军事、环境监测、医疗健康、智能家居和工业制造等领域。ZigBee是一种支持低速率传输、低功耗、安全可靠的面向可用产品及应用的无线个人局域网的全球标准,与蓝牙、Wi-Fi等其他无线个人局域网标准不同,其提供了低功耗的无线树状和网状网络,可以支持上千个无线传感器设备在网络中使用。ZigBee技术的分布式地址分配机制(Distributed Address Assignment Mechanism,DAAM)中存在网络孤立节点,这种情况导致闲置地址无法使用,且造成了资源浪费。针对这一问题,提出了一种新的树型网络地址分配和路由算法(Address Assignment Algorithm for Tree Network,AAN),在保持与原有协议兼容的基础上通过协调器节点对网络进行维护和控制,各节点根据算法设定的步骤依次进行地址空间分配。该算法可以减少网络中的闲置地址空间及网络中的孤立节点数,优化网络拓扑结构,减少建立与维护路由表所需的时间与存储空间。仿真实验结果表明,所提算法在地址分配成功率、孤立节点数以及网络深度方面优于DAAM算法。  相似文献   

18.
LEACH路由协议技术的分析及改进   总被引:1,自引:1,他引:1  
无线传感器网络作为计算、通信和传感器三项技术相结合的产物,是一种全新的信息获取和处理技术.本文在简要介绍无线传感器网络的基础上,分析了LEACH分级路由协议存在的一些问题以及如何解决这些问题.  相似文献   

19.
The area of wireless sensor networks (WSN) is currently attractive in the research community area due to its applications in diverse fields such as defense security, civilian applications and medical research. Routing is a serious issue in WSN due to the use of computationally-constrained and resource-constrained micro-sensors. These constraints prohibit the deployment of traditional routing protocols designed for other ad hoc wireless networks. Any routing protocol designed for use in WSN should be reliable, energy-efficient and should increase the lifetime of the network. We propose a simple, least-time, energy-efficient routing protocol with one-level data aggregation that ensures increased life time for the network. The proposed protocol was compared with popular ad hoc and sensor network routing protocols, viz., AODV ( [35] and [12]), DSR (Johnson et al., 2001), DSDV (Perkins and Bhagwat, 1994), DD (Intanagonwiwat et al., 2000) and MCF (Ye et al., 2001). It was observed that the proposed protocol outperformed them in throughput, latency, average energy consumption and average network lifetime. The proposed protocol uses absolute time and node energy as the criteria for routing, this ensures reliability and congestion avoidance.  相似文献   

20.
Balancing the power consumption speed in flat and hierarchical WSN   总被引:4,自引:1,他引:3  
A combination of a cluster tree routing protocol and an Ad hoc on demand vector (AODV) routing protocol is used in the latest ZigBee standard wireless sensor networks (WSNs) technology. However, the AODV routing protocol has no means by which to take into consideration the power consumption of the nodes during the routing process. Therefore, a new approach is proposed in this paper to balance the power consumption speed and to distribute the responsibilities of routing among fiat wireless sensor nodes and the three levels of hierarchical wireless sensor nodes. These three levels are based on the three types of devices, which are used in the ZigBee standard: the coordinator, the touters, and the end devices. In this paper, we have compared the original AODV routing protocol with our extension approach for the distribution of power consumption. Based on the simulation results, our new approach has achieved better performance in terms of increasing the lifetime of the fiat wireless sensor network, the personal area network (PAN)coordinator, the touters, and the whole network of the hierarchical wireless sensor network. Additionally, it has better performance in terms of distributing the power consumption among the key nodes of the wireless sensor network.  相似文献   

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