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1.
1 Introduction A Mobile Ad Hoc Network (MANET) is formed by acluster of mobile hosts and can be rapidly deployed withoutany established infrastructure or centralized administration.The design of transmission scheduling is a key design prob lem in Ad Hoc networks. Many topology dependent trans mission scheduling algorithm have been proposed to minimizethe time division multiple access frame length, in whichchanges of topology inevitably require recompilations oftransmiss…  相似文献   

2.
According to Cisco, mobile multimedia services now account for more than half the total amount of Internet traffic. This trend is burdening mobile devices in terms of power consumption, and as a result, more effort is needed to devise a range of power-saving techniques. While most power-saving techniques are based on sleep scheduling of network interfaces, little has been done to devise multimedia content adaptation techniques. In this paper, we propose a multiple linear regression model that predicts the battery voltage discharge rate for several video send bit rates in a VoIP application. The battery voltage discharge rate needs to be accurately estimated in order to estimate battery life in critical VoIP contexts, such as emergency communication. In our proposed model, the range of video send bitrates is carefully chosen in order to maintain an acceptable VoIP quality of experience. From extensive profiling, the empirical results show that the model effectively saves power and prolongs real-time VoIP sessions when deployed in power-driven adaptation schemes.  相似文献   

3.
NDN is an important instance of Information-Centric Networking.When integrating NDN into MANET,exploring new routing is a necessary task for this research area.The LSAs flooding is a common method to obtain network topology during route establishment.However,the LSAs flooding often results in a broadcast storm in high-density MANET.Using the MPR set proposed in the OLSR can effectively reduce the number of LSAs in the process of route establishment and can further solve the broadcast storm.In this paper,an enhanced neighbor discovery protocol firstly is designed to establish a MPR set.The new protocol can effectively avoid the problem incurred by unidirectional links that impact the network performance in a wireless environment.And then a new and proactive routing NOLSR based on OLSR for NDN-MANET is proposed to support NDN in MANET.And another important work is that NOLSR is implemented on top of NDN Forwarding Daemon NFD.Finally,we make a comparative analysis between NOLSR and the two most relative schemes such as traditional LSA-flooding and the scheme[1]by emulation experiments in the NDN emulator mini-NDN.  相似文献   

4.
To reduce the network deployment cost and provide voice, message and low rate data services in remote pastoral areas of Tibet effectively, an integrated wireless communication system utilizing MANET(Mobile Ad hoc Network) is proposed. The sparse mobile devices, assisted with the solar-powered multi-functional standing stations mainly on networking maintenance and routing arrangement, self-organize into a MANET. The topology of the standing stations is designed for networking robust and to simplify the routing method and energy strategy. Then in the OMNe T++(Objective Modular Network Test bed in C++) simulation, the energy consumption is analysis while adjusting routing with the different energy status of the standing stations. The result shows that the standing stations should adjust routing as well as control the mobile devices’ activity level according to the energy states of the standing stations and their adjacent mobile devices.  相似文献   

5.
The mobile agent is a computer program that is able to migrate continuously among hosts in a net- work and use host service to meet its task. The host, known as workplace, can be regarded as a proxy of social member. The sequence of workplaces on which the mobile agent completed its tasks is called path. In this paper, we propose a dynamic building method of mobile agent path with minimum payment based on referral. By referral, the next workplace of mobile agent can be recommended by the current workplace provider based on his acquaintance knowledge. The simulation results on a random network model show that the more acquaintance relationships there are on the referral network, the more efficiently the mo- bile agent path can be built, and the fewer costs need to be paid on the path.  相似文献   

6.
A novel scheme is presented to integrate mobile ad hoc networks (MANETs) with the lnternet and support mobility across wireless local area networks (WLANs) and MANETs. The mobile nodes, connected as a MANET, employ the optimize d link state routing (OLSR) protocol for routing within the MANET. Mobility management across WLANs and MANETs is achieved through the hierarchical mobile IPv6 (HMIPv6) protocol. The performance is evaluated on a HMIPv6 based test-bed composed of WLANs and MANETs. The efficiency gain obtained from using HMIPv6 in such a hybrid network is investigated. The investigation result shows that the use of HMIPv6 can achieve up to 27% gain on reducing the handoff latency when a mobile roams within a domain. Concerning the reduction of the signaling load on the lnternet, the use of HMIPv6 can achieve at least a 54% gain and converges to 69%.  相似文献   

7.
Trust management has been proven to be a useful technology for providing security service and as a consequence has been used in many applications such as P2P, Grid, ad hoc network and so on. However, few researches about trust mechanism for Internet of Things (IoT) could be found in the literature, though we argue that considerable necessity is held for applying trust mechanism to IoT. In this paper, we establish a formal trust management control mechanism based on architecture modeling of IoT. We decompose the IoT into three layers, which are sensor layer, core layer and application layer, from aspects of network composition of loT. Each layer is controlled by trust management for special purpose: self-organized, affective routing and multi-service respectively. And the final decision-making is performed by service requester according to the collected trust information as well as requester' policy. Finally, we use a formal semantics-based and fuzzy set theory to realize all above trust mechanism, the result of which provides a general framework for the development of trust models of IoT.  相似文献   

8.
Mobile free space optical networks have aroused much attention due to the ability of providing high speed connectivity over long distance using the wireless laser links,while requiring relatively high available bandwidth resource and less energy consumption.However,maintaining the network with laserlinks is quite challenging due to a number of issues,such as the link fragility,the difficulty in pointingand tracking of the link,which also raises the great difficulty in the control of the network.In this paper,we present the methodology for the deployment of the mobile freespace optical networks based on our proposed OpenFlow-based control architecture.In addition,a new routing scheme is proposed and demonstrated on the testbed based on this control architecture.Delivery ratio,average delivery delay and time complexity are given to verify the performance of the OpenFlow-based control architecture.  相似文献   

9.
The virtual network embedding/ mapping problem is an important issue in network virtualization in Software-Defined Networking (SDN). It is mainly concerned with mapping virtual network requests, which could be a set of SDN flows, onto a shared substrate network automatically and efficiently. Previous researches mainly focus on developing heuristic algorithms for general topology virtual network. In practice however, the virtual network is usually generated with specific topology for specific purpose. Thus, it is a challenge to optimize the heuristic algorithms with these topology information. In order to deal with this problem, we propose a topology-cognitive algorithm framework, which is composed of a guiding principle for topology algorithm developing and a compound algorithm. The compound algorithm is composed of several sub- algorithms, which are optimized for specific topologies. We develop star, tree, and ring topology algorithms as examples, other sub- algorithms can be easily achieved following the same framework. The simulation results show that the topology-cognitive algorithm framework is effective in developing new topology algorithms, and the developed compound algorithm greatly enhances the performance of the Revenue/Cost (R/C) ratio and the Runtime than traditional heuristic algorithms for multi-topology virtual network embedding problem.  相似文献   

10.
MANET(Mobile Ad Hoc Network)is a collection of wireless mobile nodes forming a temporary communica-tion network without the aid of any established infrastructure or centralized administration.The lifetime of a MANETdepends on the battery resources of the mobile nodes.So energy consumption may one of important design criterions forMANET.With changing the idle model to sleep model in the grid environment,this paper proposes a new energy-awarerouting protocol.Performance simulation results show that the proposed strategy can dynamic balance the traffic load in-side the whole network,extend the lifetime of a MANET,and without decreasing the throughput ratio.  相似文献   

11.
MANET环境下基于能量保护的路由策略及其研究进展   总被引:3,自引:0,他引:3  
移动Ad hoc网络是由一组带有无线收发装置的移动节点组成的一个支持多跳的临时性的网络自治系统。由于移动自组网的大多数节点是由有限寿命的电池来提供能量,因此节能策略正逐步成为设计和评价路由协议的一个重要依据。通过分析现有移动自组网的节能路由策略,给出了未来该领域的若干研究方向。  相似文献   

12.
移动自组网能量保护策略研究进展   总被引:13,自引:1,他引:12  
许力  张继东  郑宝玉  杨震 《通信学报》2004,25(9):93-103
移动自组网是一组带有无线收发装置的移动节点组成的一个支持多跳的临时性的网络自治系统,由于移动自组网的大多数节点是由有限寿命的电池来提供的,因此能量保护策略成为该网络所有协议层的关键问题。本文回顾了移动自组网能量保护策略的研究进展,对有关策略进行了评述,最后结合跨层设计思想给出了基于跨层协同的能量保护构架及其包含的研究方向。  相似文献   

13.
自组网是兼做路由器的移动节点组成的移动无线网络,不依靠通信基础设施。本文提出了一个工作于物理层和MAC层之上、网络层之下的基于自组网的节能协作算法,其核心思想是构造虚拟主干网,使位于虚拟主干网外的节点工作于休眠状态,从而减少电源消耗。  相似文献   

14.
Nikos  Dimitris  Christos   《Ad hoc Networks》2007,5(3):289-298
Security of mobile ad hoc networks (MANET) has become a more sophisticated problem than security in other networks, due to the open nature and the lack of infrastructure of such networks. In this paper, the security challenges in intrusion detection and authentication are identified and the different types of attacks are discussed. We propose a two-phase detection procedure of nodes that are not authorized for specific services and nodes that have been compromised during their operation in MANET. The detection framework is enabled with the main operations of ad hoc networking, which are found at the link and network layers. The proposed framework is based on zero knowledge techniques, which are presented through proofs.  相似文献   

15.
由于自组网独特的特性,在该网络中支持QoS非常困难,需要进行系统研究。本文首先分析了自组网中QoS支持面临的挑战,接着从系统角度出发,结合自组网的特点,在QoS模型和QoS支持体系以及体系中具体的QoS技术等方面对自组网QoS支持做了详尽的分析与探讨,同时指出:定义自组网QoS模型需要综合考虑应用需求和网络特性;实现QoS模型可以采用分层QoS支持体系或跨层QoS支持体系,而后者将是今后研究的重点;结合路由层、MAC层和物理层的跨层QoS支持体系具有研究价值。  相似文献   

16.
李志远 《通信技术》2008,41(5):94-96
服务通告和发现在MANET(Mobile Ad hoc Networks)网络中,是一个十分重要的组成部分.现有的服务通告和发现协议不是为MANET网络设计的.文章提出了一个适合MANET、基于ZRP(Zone Routing Protocol)的服务通告及发现协议.服务的通告与发现存在于ZRP路由控制分组中,避免了周期性的通告给MANET网络带来的负载,节约了有限的带宽和设备的能耗.  相似文献   

17.
The lifetime of a mobile ad hoc network (MANET) depends on the durability of the mobile hosts' battery resources. In the IEEE 802.11 Power Saving Mode, a host must wake up at every beacon interval, to check if it should remain awake. Such a scheme fails to adjust a host's sleep duration according to its traffic, thereby reducing its power efficiency. This paper presents new MAC protocols for power saving in a single hop MANET. The essence of these protocols is a quorum-based sleep/wake-up mechanism, which conserves energy by allowing the host to sleep for more than one beacon interval, if few transmissions are involved. The proposed protocols are simple and energy-efficiency. Simulation results showed that our protocols conserved more energy and extended the lifetime of a MANET.  相似文献   

18.
A survey of routing attacks in mobile ad hoc networks   总被引:3,自引:0,他引:3  
Recently, mobile ad hoc networks became a hot research topic among researchers due to their flexibility and independence of network infrastructures, such as base stations. Due to unique characteristics, such as dynamic network topology, limited bandwidth, and limited battery power, routing in a MANET is a particularly challenging task compared to a conventional network. Early work in MANET research has mainly focused on developing an efficient routing mechanism in such a highly dynamic and resource-constrained network. At present, several efficient routing protocols have been proposed for MANET. Most of these protocols assume a trusted and cooperative environment. However, in the presence of malicious nodes, the networks are vulnerable to various kinds of attacks. In MANET, routing attacks are particularly serious. In this article, we investigate the state-of-the-art of security issues in MANET. In particular, we examine routing attacks, such as link spoofing and colluding misrelay attacks, as well as countermeasures against such attacks in existing MANET protocols.  相似文献   

19.
Mobile ad hoc networks (MANET) comprise mobile hosts in a network bereft of base stations and characterized by a highly dynamic network topology. The MANET environment contains unpredictable obstacles, such as mountains, lakes, buildings, or regions without any hosts, impeding or blocking message relay. This study proposes geocasting protocols for sending short message from a source host to single or multiple geocasting regions in ad hoc networks. The proposed protocols keep messages away from unpredictable obstacles and create a small flooding region. Experimental results show that a source host can send a short message to all hosts located in single or multiple geographical areas with a high success rate and low flooding overhead.  相似文献   

20.
Due to the highly dynamicity and absence of a fixed infrastructure in wireless mobile ad hoc networks (MANET), formation of a stable virtual backbone through which all the network hosts are connected is of great importance. In this paper, a learning automata-based distributed algorithm is proposed for constructing the most stable virtual backbone of the MANET. To do so, the backbone formation problem is first modeled by the stochastic version of the bounded diameter minimum spanning tree (BDMST) problem. Then, the network backbone is constructed by solving the stochastic BDMST problem for the network topology graph. Several simulation experiments are conducted to investigate the efficiency of the proposed backbone formation protocol. The obtained results are compared with those of the best existing methods. Numerical results show the superiority of the proposed method over the others in terms of backbone lifetime, end-to-end delay, backbone size, packet delivery ratio, and control message overhead.  相似文献   

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