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1.
Network coding,which exploits the broadcast nature of wireless medium,is an effective way to improve network performance in wireless multi-hop networks,but the first practical wireless network coding system COPE cannot actively detect a route with more coding opportunities and limit the coding structure within two-hop regions.An on-demand coding-aware routing scheme(OCAR)for wireless Mesh networks is proposed to overcome the limitations specified above by actively detecting a route with more coding opportunities along the entire route rather than within two-hop regions.Utilizing more coding opportunities tends to route multiple flows 'close to each other' while avoiding interference requires routing multiple flows 'away from each other'.OCAR achieves a tradeoff by adopting RCAIA as routing metric in route discovery,which is not only coding-aware but also considers both inter and intra flow interference.Simulation results show that,compared with Ad-hoc on-demand distance vecfor routing(AODV)and AODV+COPE,OCAR can find more coding opportunities,thus effectively increase network throughput,reduce end to end delay and alleviate network congestion.  相似文献   

2.
Robust multi-path routing for dynamic topology in wireless sensor networks   总被引:1,自引:0,他引:1  
Wireless sensor networks are being widely researched and are expected to be used in several scenarios. On the leading edge of treads, on-demand, high-reliability, and low-latency routing protocol is desirable for indoor environment applications. This article proposes a routing scheme called robust multi-path routing that establishes and uses multiple node-disjoint routes. Providing multiple routes helps to reduce the route recovery process and control the message overhead. The performance comparison of this protocol with dynamic source routing (DSR) by OPNET simulations shows that this protocol is able to achieve a remarkable improvement in the packet delivery ratio and average end-to-end delay.  相似文献   

3.
Wireless Networks - Ad hoc wireless networks have aroused much interest of the scientific community in the last two decades. The provision of Quality of Service (QoS) is a prominent challenge in...  相似文献   

4.
In many applications, wireless ad-hoc networks are formed by devices belonging to independent users. Therefore, a challenging problem is how to provide incentives to stimulate cooperation. In this paper, we study ad-hoc games—the routing and packet forwarding games in wireless ad-hoc networks. Unlike previous work which focuses either on routing or on forwarding, this paper investigates both routing and forwarding. We first uncover an impossibility result—there does not exist a protocol such that following the protocol to always forward others' traffic is a dominant action. Then we define a novel solution concept called cooperation-optimal protocols. We present Corsac, a cooperation-optimal protocol which consists of a routing protocol and a forwarding protocol. The routing protocol of Corsac integrates VCG with a novel cryptographic technique to address the challenge in wireless ad-hoc networks that a link’s cost (i.e., its type) is determined by two nodes together. Corsac also applies efficient cryptographic techniques to design a forwarding protocol to enforce the routing decision, such that fulfilling the routing decision is the optimal action of each node in the sense that it brings the maximum utility to the node. We evaluate our protocols using simulations. Our evaluations demonstrate that our protocols provide incentives for nodes to forward packets. Additionally, we discuss the challenging issues in designing incentive-compatible protocols in ad hoc networks. Part of this paper appeared in a conference version [49]. Sheng Zhong was supported in part by NSF grants ANI-0207399 and CNS-0524030. Yang Richard Yang was supported in part by NSF grants ANI-0207399, ANI-0238038, and CNS-0435201. This work was partly done while Sheng Zhong was at Yale University; Yanbin Liu was at University of Texas at Austin. Sheng Zhong is an assistant professor in the State University of New York at Buffalo. He received his PhD (2004) from Yale University and his ME (1999), BS (1996) from Nanjing University, China, all in computer science. His research interests include economic incentives and privacy protection, particularly incentive and privacy problems in mobile computing and data mining. Li Erran Li received his B.E. in Automatic Control from Beijing Polytechnic University in 1993, his M.E. in Pattern Recognition from the Institute of Automation, Chinese Academy of Sciences, in 1996, and his Ph.D. in Computer Science from Cornell University in 2001 where Joseph Y. Halpern was his advisor. He is presently a member of the Networking Research Center in Bell Labs. His research interests are in networking with a focus on wireless networking and mobile computing. He has served as a program committee member for several conferences including ACM MobiCom, ACM MobiHoc, IEEE INFOCOM and IEEE ICNP. He is a guest editor for JSAC special issue on Non-Cooperative Behavior in Networking. He has published over 30 papers. Yanbin Liu received her B.E. degree in Computer Science and Technology from Tsinghua University (1993), Beijing, China, in 1993, and her M.S. degree in Computer Science from the University of Texas at Austin (1998), where is a Ph.D. candidate. Since 2006, he has been with IBM TJ Watson Research Center, Hawthorne, NY. Her research interests are in real-time systems, grid computing, mobile computing, and computer networks. Yang Richard Yang received his B.E. degree in Computer Science and Technology from Tsinghua University, Beijing, China, in 1993, and his M.S. and Ph.D. degrees in Computer Science from the University of Texas at Austin in 1998 and 2001, respectively. Since 2001, he has been with the Department of Computer Science, Yale University, New Haven, CT, where currently he is an Associate Professor. His current research interests are in computer networks, mobile computing, and sensor networks. He leads the Laboratory of Networked Systems (LANS) at Yale University.  相似文献   

5.
Sajwan  Mohit  Gosain  Devashish  Sharma  Ajay K. 《Wireless Networks》2019,25(5):2603-2620
Wireless Networks - In this article, we propose a novel routing algorithm for wireless sensor network, which achieves uniform energy depletion across all the nodes and thus leading to prolonged...  相似文献   

6.
The mobility modelling is one of the most important issues in wireless ad-hoc networks, therefore our research activities are focused on this area. This paper presents a new solution for map-based mobility modelling system which enables direct position control for mobile stations. This system, based on the cooperation model between OPNET Modeler simulation environment and MATLAB tool, provides fully automated process of direct position control with respect to the initial requirement and attributes. Firstly, the input information are collected in OPNET Modeler and forwarded to MATLAB environment. After that, MATLAB process a map source stored as a bitmap image and runs the function which generates a set of coordinates. These coordinates are transferred back to OPNET Modeler and used for the direct movement control of mobile stations. Our system developed was evaluated by the set of simulation runs and the results are placed on the end of this paper.  相似文献   

7.
Hossam  Tiantong  Hussein T.   《Ad hoc Networks》2005,3(6):717-743
The IEEE 802.11 standard is the most popular Medium Access Control (MAC) protocol for wireless local area networks. However, in an ad-hoc environment, the Point Coordination Function (PCF), defined in the standard, cannot be readily used. This is due to the fact that there is no central authority to act as a Point Coordinator (PC). Peer-to-peer ad-hoc mode in the IEEE 802.11 standard only implements the Distributed Coordination Function (DCF). In this paper, an efficient and on-the-fly infrastructure is created using our proposed Mobile Point Coordinator (MPC) protocol. Based on this protocol, we also develop an efficient MAC protocol, namely MPC–MAC. Our MAC protocol extends the IEEE 802.11 standard for use in multi-hop wireless ad-hoc networks implementing both the DCF and PCF modes of operation. The goal, and also the challenge, is to achieve QoS delivery and priority access for real-time traffic in ad-hoc wireless environments while maintaining backward compatibility with the IEEE 802.11 standard. The performance of MPC–MAC is compared to the IEEE 802.11 DCF-based MAC without MPC. Simulation experiments show that in all cases the use of PCF benefits real-time packets by decreasing the average delay and the discard ratio. However, this may come at the expense of increasing the average delay for non-real-time data. On the other hand, the discard ratio for both real-time and non-real-time packets improves with the use of PCF. Therefore, our MPC–MAC outperforms the standard DCF IEEE 802.11 MAC protocol in multi-hop ad-hoc environments.  相似文献   

8.
刘惠敏 《信息技术》2007,31(9):147-149
对目前AdHoc无线移动网络中存在的路由问题进行分析,并从多路径路由的要求出发,讨论把动态源路由协议DSR改造成多源路径协议的可行性,并提出了具体的实现算法。文中所提出的多径源路由协议为无线网络的路由协议的研究提供了重要的理论支持。  相似文献   

9.
The wireless network should provide high throughput and positive status and this paper suggest a system that supports real-time communications with excellence of service necessities for application based on wireless communications. In addition a hybrid network that interconnects both mobile networks and wireless networks. By inheriting the features of Solid Rocket Booster technology for mobile and wireless networks the race condition, and invalid condition problem has been solved. The number of packets received may vary based on the parameter like mobility, energy, memory, bandwidth, jamming and other parameter. In past years many algorithm has been proposed for increasing the probability of packet delivery but it’s still a challenge. This paper uses an algorithm called intelligent packet carrying systems; it provides a tracking mechanism that tracks nodes in rural places. The effectives and reability has been calculated and the results are obtained using OPNET simulator.  相似文献   

10.
Clustering routing protocols excel in several aspects of wireless sensor networks (WSNs). This article proposes a clustering and multihop routing protocol (CMRP). In CMRP, a node independently makes its decision to compete for becoming a cluster head or join a cluster, according to its residual energy and average broadcast power of all its neighbors. To minimize the power consumption of the cluster head, CMRP sends the data in a power-aware multihop manner to the base station (BS) through a quasi-fixed route (QFR). In addition, CMRP presents a transmission power control algorithm with dynamic intercluster neighbor position estimation (DCNPE) to save energy. Simulation results show that the performance of CMRP is better than the hybrid, energy-efficient, distributed clustering approach (HEED). In the best case, CMRP increases the sensor network lifetime by 150.2%.  相似文献   

11.
This paper presents a distributed and adaptive fluctuation control scheme for many-to-one routing(FCM) in wireless sensor networks.Unlike well-known topology control schemes,the primary design objective is to reduce the fluctuation which happens due to overload of sensors in a data collection tree.More specifically,an estimation model of a sensor available capacity based on the number of its neighbors is proposed.In addition,this paper proposes a parent selection mechanism by three-way handshake.With such model and the selection mechanism,it is ensured that the load of a sensor does not exceed its available capacity.Finally,an adaptive maintenance mechanism is proposed to adjust the estimation of a sensor available capacity as the network environment changes.Simulation results demonstrate the effectiveness of the scheme.  相似文献   

12.
This paper proposes an approach called PC-CORP (Power Control based Cooperative Opportunistic Routing Protocol) for WSN (Wireless Sensor Networks), providing robustness to the random variations in network connectivity while ensuring better data forwarding efficiency in an energy efficient manner. Based on the realistic radio model, we combine the region-based routing, rendezvous scheme, sleep discipline and cooperative communication together to model data forwarding by cross layer design in WSN. At the same time, a lightweight transmission power control algorithm called PC-AIMD (Power Control Additive Increase Multiplicative Decrease) is introduced to utilize the cooperation of relay nodes to improve the forwarding efficiency performance and increase the robustness of the routing protocol. In the simulation, the performance of PC-COPR is investigated in terms of the adaptation of variations in network connectivity and satisfying the QoS requirements of application.  相似文献   

13.
针对光突发交换(OBS)网络的多路由机制多是考虑一种业务而对多业务区分的多路由机制研究偏少这种现状,提出了一种支持业务区分的多路由(MRSD)机制。在发送各个服务等级的业务之前,首先在没有共享风险链路的多条路由上发送请求包获得各条路由上的多种优先级业务的负载情况,然后根据爱尔兰固定点近似分析法计算各种优先级业务在不同路由上的丢包率,并为每种优先级业务选择一条使本业务丢包率最小的路由;在一个核心节点内,则采用基于额外偏置时间的业务区分方法实现不同优先级业务的区分,将各种业务根据链路状态信息分配到没有共享风险链路的多条路由上去传输,从而在减少突发丢失率(BLP)的同时实现了多种优先级业务在路由上的区分。仿真结果表明,这种多路由机制能够有效降低网络的BLP,实现区分服务。  相似文献   

14.
The routing performance in mobile ad hoc networks (MANETs) relies on the co-operation of the individual nodes that constitute the network. The existence of misbehaving nodes may paralyze the routing operation in MANETs. To overcome this behavior, the trustworthiness of the network nodes should be considered in the route selection process combined with the hop count. The trustworthiness is achieved by measuring the trust value for each node in the network. In this paper, a new protocol based on self monitoring (agent-based) and following the dynamic source routing (DSR) algorithm is presented. This protocol is called agent-based trusted dynamic source routing protocol for MANETs. The objective of this protocol is to manage trust information locally with minimal overhead in terms of extra messages and time delay. This objective is achieved through installing in each participated node in the network a multi-agent system (MAS). MAS consists of two types of agents: monitoring agent and routing agent. A new mathematical and more realistic objective model for measuring the trust value is introduced. This model is weighted by both number and size of routed packets to reflect the “selective forwarding” behavior of a node. The performance evaluation via simulation shows that our protocol is better than standard and trusted DSR. The simulation is done over a variety of environmental conditions such as number of malicious nodes, host density and movement rates.  相似文献   

15.
Dipanjan  Anupam  Yelena 《Ad hoc Networks》2006,4(2):204-224
In this paper, we propose GSR: a new routing and session management protocol for ad-hoc networks as an integral part of a service discovery infrastructure. Traditional approaches place routing at a layer below service discovery. While this distinction is appropriate for wired networked services, we argue that in ad-hoc networks this layering is not as meaningful and show that integrating routing with discovery infrastructure increases system efficiency. Central to our protocol is the idea of reusing the path created by the combination of a service discovery request and a service advertisement for data transmission. This precludes the need to use separate routing and discovery protocols. GSR also combines transport layer features and provides end-to-end session management that detects disconnections, link and node failures and enables service-centric session redirection to handle failures. This enables GSR to accommodate service-centric routing apart from the traditional node-centric routing. We compare GSR with AODV in terms of packet delivery ratio, response time and average number of hops traveled by service requests as well as data. GSR achieves better packet delivery ratio with a minor increase of the average packet delivery delay.  相似文献   

16.
To accommodate real-time multimedia application while satisfying application QoS requirements in a wireless ad-hoc network, we need QoS control mechanisms. In this paper, we propose a new routing mechanism to support real-time multimedia communication by efficiently utilize the limited wireless network capacity. Our mechanism considers a wireless ad-hoc network composed of nodes equipped with multiple network interfaces to each of which a different wireless channel can be assigned. By embedding information about channel usage in control messages of OLSRv2, each node obtains a view of topology and bandwidth information of the whole network. Based on the obtained information, a source node determines a logical path with the maximum available bandwidth to satisfy application QoS requirements. Through simulation experiments, we confirmed that our proposal effectively routed multimedia packets over a logical path avoiding congested links. As a result, the load on a network is well distributed and the network can accommodate more sessions than QOLSR. We also conducted practical experiments using wireless ad-hoc relay nodes with four network interfaces and verified the practicality of our proposal.  相似文献   

17.
Buratti  Chiara  Verdone  Roberto 《Wireless Networks》2018,24(5):1699-1714

We consider a TDMA-based multi-hop wireless sensor network, where nodes send data to a sink, which is aware of received powers at all receivers; the sink is responsible for creating the network topology and assigning time slots to links. Under this centralized approach, we propose two algorithms that jointly define the tree topology connecting nodes to the sink, and assign time slots, avoiding any packet loss. In contrast with previous works, the proposed algorithms accurately account for interference effects; when evaluating the signal-to-interference ratio to establish the tree and schedule transmissions, we consider the sum of all actual interfering signals, a fact of relevance for networks with increasing number of nodes. Optimal selection of transmit powers, minimizing energy consumption, is also applied. Our algorithms are compared to a benchmark solution and other proposals from the literature; it is shown that they bring to better radio resource utilization, higher throughput and lower energy consumption, while keeping the average delay limited.

  相似文献   

18.
Telecommunication Systems - Queueing models play a significant role in analysing the performance of power management systems in various electronic devices and communication systems. This paper...  相似文献   

19.
Admission control (AC) is a mechanism for meeting bandwidth requirements of data transmissions. Early research on admission control for wireless mesh networks (WMNs) was centered around single-path routing. Compared to single-path routing, parallel multipath routing may offer more reliable network services and better load balancing. Applying admission control to multipath routing could further improve service quality, but it also faces a number of challenges. For example, transmission on one path may affect transmission on a neighboring path. Addressing these challenges, this paper presents an AC algorithm on parallel multipath routing for WMNs. In particular, we formulate an optimization problem for achieving the best service based on available bandwidth and bandwidth consumption of to-be-admitted data sessions. While solving this problem is a complex task, we devise an optimal algorithm for selecting two node-disjoint paths with rate allocation, and propose a distributed multipath routing and admission control protocol to achieve a near-optimal solution. Simulations show that MRAC is efficient and effective in meeting bandwidth requirements.  相似文献   

20.
In this work we study the combination of multi-cost routing and adjustable transmission power in wireless ad hoc networks, so as to obtain dynamic energy- and interference-efficient routes to optimize network performance. In multi-cost routing, a vector of cost parameters is assigned to each network link, from which the cost vectors of candidate paths are calculated. Only at the end these parameters are combined in various optimization functions, corresponding to different routing algorithms, for selecting the optimal path. The multi-cost routing problem is a generalization of the multi-constrained problem, where no constraints exist, and is also significantly more powerful than single-cost routing. Since energy is an important limitation of wireless communications, the cost parameters considered are the number of hops, the interference caused, the residual energy and the transmission power of the nodes on the path; other parameters could also be included, as desired. We assume that nodes can use power control to adjust their transmission power to the desired level. The experiments conducted show that the combination of multi-cost routing and adjustable transmission power can lead to reduced interference and energy consumption, improving network performance and lifetime.  相似文献   

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