Multi-hop Clustering Based on Neighborhood Benchmark in Mobile Ad-hoc Networks

Large-scale mobile ad-hoc networks require flexible and stable clustered network structure for efficient data collection and dissemination. In this paper, a technique is presented to construct multi-hop clusters with balanced sizes, based on the neighborhood benchmark (NB) to quantify the connectivity and link stability of mobile nodes. By exploiting autonomous clusterhead selection and a specialized handshake process with the clusterheads, the nodes with highest NB scores are selected as clusterheads and all the clusters constructed are connected. The deviation of cluster sizes is kept small using a partial probability-based approach. Our technique generates highly stable multi-hop clusters with low overhead, and provides the flexibility of controlling the cluster radius adaptively for various network applications.     

Mobility-Based Backbone Formation in Wireless Mobile Ad-hoc Networks

In this paper, the well-known network backbone formation problem is modeled as the stochastic min-degree constrained minimum spanning tree (md-MST) problem, where the link duration is associated with the edge weight. Then, a decentralized learning automata-based algorithm is proposed to form the most stable backbone of the wireless mobile ad hoc network (MANET) by finding a near optimal solution to the stochastic md-MST problem of the network topology graph. The proposed method significantly decreases the network overhead and shortens the network delay by reducing the number of intermediate forwarding hosts. It also extends the backbone lifetime by selection of the links with the maximum expected duration. The convergence of the proposed algorithm to the most stable network backbone is proven on the basis of the Martingale theorem. Several simulation experiments are conducted to investigate the efficiency of the proposed backbone formation algorithm. Numerical results show the superiority of the proposed method over the existing methods in terms of the backbone lifetime, end-to-end delay, backbone size, packet delivery ratio, and control message overhead.     

RETRACTED ARTICLE: Improved AODV Based on TOPSIS and Fuzzy Algorithms in Vehicular Ad-hoc Networks

Wireless Personal Communications - The ad-hoc on-demand distance vector (AODV) routing protocol is one of the most widely used routing protocols in VANETs. The AODV finds the shortest path that is...     

基于节能的移动Ad Hoc网络AODV路由协议改进

移动Ad Hoc网络是一种无基础设施的新型无线网络.由于军事和抢险救灾等方面的需要,移动Ad Hoc网络路由协议成为当前研究的热点之一.在AODV协议的基础上,提出了一种节能的路由协9义AODVE,并采用了备份路由机制.仿真结果验证了,相对于AODV,该协议在分组传输率、时延和路由开销方面得到了较大的改善.     

Hash-Based Virtual Hierarchies for Scalable Location Service in Mobile Ad-hoc Networks

A location service is an essential prerequisite for geographic routing protocols for MANETs. We present VHLS, a new distributed location service protocol, that features a dynamic location server selection mechanism and adapts to network traffic workload, minimizing the overall location service overhead. We demonstrate that the ratio of location queries to updates is an important performance parameter in such protocols. Our analysis and simulations show that VHLS provides better query success rates, location service quality, and geographic routing performance than the GLS and GHLS protocols. VHLS also scales well as the network size and traffic workload increases.     

无线自组网中AODV路由协议的Linux实现

基于AODV(Ad hoc On-Demand Distance Vector)路由协议在无线移动自组网中应用的基本原理,针对Linux操作系统路由体系结构特点,深入分析了在这种路由体系结构中实现AODV路由协议的主要关键技术和难点,给出了解决问题的办法,提出了在Linux操作系统上实现AODV路由协议的方案并在实践中加以验证,证明这种方案切实可行。     

Autonomous Ant-based Public Key Authentication Mechanism for Mobile Ad-hoc Networks

In mobile ad-hoc networks (MANETs), where there is no centralized authority to provide authentication, trust and reputation mechanisms are applied to maintain security by identifying trustworthy and untrustworthy nodes. However, traditional authentication mechanisms are not viable for MANETs due to the lack of infrastructure and frequent topology changes. In this paper, we propose a self-organized and localized public key authentication mechanism based on ant colony systems. Every node generates its own public-private key pair, issues certificates to neighboring nodes and provides on-demand authentication services by means of gathering certificate chains towards a target node. Pheromone concentration left by ants along the path of the certificate chains represents the trust level of a node towards other nodes. This model is able to authenticate public keys by selecting the most trustworthy certificate chains gathered by ants and can identify and exclude certificate chains with malicious nodes.     

An Ant-based Multipath Routing Algorithm for QoS Aware Mobile Ad-hoc Networks

In the wireless ad-hoc network management, Quality of Service (QoS) is an important issue. Along with the QoS ensuring, another desirable property is the network reliability. In data communications, multi-path routing strategy can cope with the problem of traffic overloads while balancing the network resource consumption. In this paper, we propose a new multipath routing algorithm for QoS-sensitive multimedia services. Based on the ant colony optimization technique, the proposed algorithm can establish effective multi-paths to enhance the network reliability. According to the load balancing strategy, data packets are adaptively distributed through the established paths while maintaining an acceptable level of QoS requirement. The most important feature of the proposed approach is its adaptability to current traffic conditions. Simulation results indicate the superior performance of the proposed algorithm, while other schemes cannot offer such an attractive performance balance.     

基于Grover搜索算法的MANET网络路由协议

In Mobile Ad-hoc Networks (MA-NETs), routing protocols directly affect various indices of network Quality of Service (QoS), so they play an important role in network performance. To address the drawbacks associated with traditional routing protocols in MANETs, such as poor anti-fading perfor-mance and slow convergence rate, for basic Dynamic Source Routing (DSR), we propose a new routing model based on Grover’s sear-ching algorithm. With this new routing model, each node maintains a node vector function, and all the nodes can obtain a node probability vector using Grover’s algorithm, and then select an optimal routing according to node probability. Simulation results show that compared with DSR, this new routing protocol can effectively extend the network lifetime, as well as reduce the network delay and the number of routing hops. It can also significantly improve the anti-jamming capa-bility of the network.     

基于802.11 MAC的移动Ad Hoc网络AODV路由协议改进算法

基于802.11的Ad Hoc网络AODV路由协议会引入通信盲区问题,使路由发现信息建立的路由不能很好地满足高速数据分组的传输,本文在传统通信盲区解决方案的基础上提出一种AODV路由协议改进算法.Opnet仿真表明,改进算法能有效地提高Ad-hoc网络性能.     

DOA: DSR over AODV Routing for Mobile Ad Hoc Networks

We present a lightweight hierarchical routing model, Way Point Routing (WPR), in which a number of intermediate nodes on a route are selected as waypoints and the route is divided into segments by the waypoints. Waypoints, including the source and the destination, run a high-level intersegment routing protocol, while the nodes on each segment run a low-level intrasegment routing protocol. One distinct advantage of our model is that when a node on the route moves out or fails, instead of discarding the whole original route and discovering a new route from the source to the destination, only the two waypoint nodes of the broken segment have to find a new segment. In addition, our model is lightweight because it maintains a hierarchy only for nodes on active routes. On the other hand, existing hierarchical routing protocols such as CGSR and ZRP maintain hierarchies for the entire network. We present an instantiation of WPR, where we use DSR as the intersegment routing protocol and AODV as the intrasegment routing protocol. This instantiation is termed DSR over AODV (DOA) routing protocol. Thus, DSR and AODV—two well-known on-demand routing protocols for MANETs—are combined into one hierarchical routing protocol and become two special cases of our protocol. Furthermore, we present two novel techniques for DOA: one is an efficient loop detection method and the other is a multitarget route discovery. Simulation results show that DOA scales well for large networks with more than 1,000 nodes, incurring about 60 percent-80 percent less overhead than AODV, while other metrics are better than or comparable to AODV and DSR.     

GUIDE-gradient: A Guiding Algorithm for Mobile Nodes in WLAN and Ad-hoc Networks

Whereas there is a lot of work related to finding the location of users in WLAN and ad-hoc networks, guiding users in these networks remains mostly an unexplored area of research. In this paper we present the concept of node-to-node guidance and introduce a method that can be used to implement it. This method relies on the computation of a local gradient in the neighborhood of the moving node. We named this protocol GUIDE-gradient, which is a GPS-free and infrastructure-free node-to-node guiding system. In this paper we also discuss how the guiding algorithm can be generalized to node-to-node guidance in multihop ad-hoc networks.     

A Reliable Multicast Routing Protocol Based on Recovery Points and FEC in Mobile Ad-hoc Networks

Multicasting is an essential service for mobile ad-hoc networks. A major challenge for multicasting in mobile ad-hoc networks (MANETs) is the unstable forwarding path. This work presents a reliable multicasting protocol for mobile ad-hoc networks. A virtual backbone is used as a shared structure for multiple sessions. A lost packet recovery scheme is developed for reliable packet transmission, called the Recovery Point (RP) scheme. The RP scheme maintains the data packets received from the source for recovering lost packets for its downstream RPs. In addition, we combine the Forward Error Correction (FEC) technology with our RP scheme to enhance the reliability of our RP scheme. A mergence scheme for RP is also proposed to avoid excessive control overhead. Our RP and FEC based scheme can be used to improve the reliability and efficiency of the traditional non-acknowledged multicasting approach. Experiments were conducted to evaluate the proposed multicasting scheme. The results demonstrate that our scheme outperforms other schemes in terms of packet delivery ratio and multicast efficiency. Furthermore, the simulation results also demonstrate that our approach is stable in networks with high mobility.

A key management and secure routing integrated framework for Mobile Ad-hoc Networks

Key management (KM) and secure routing (SR) are two most important issues for Mobile Ad-hoc Networks (MANETs), but previous solutions tend to consider them separately. This leads to KM–SR interdependency cycle problem. In this paper, we propose a KM–SR integrated scheme that addresses KM–SR interdependency cycle problem. By using identity based cryptography (IBC), this scheme provides security features including confidentiality, integrity, authentication, freshness, and non-repudiation. Compared to symmetric cryptography, traditional asymmetric cryptography and previous IBC schemes, this scheme has improvements in many aspects. We provide theoretical proof of the security of the scheme and demonstrate the efficiency of the scheme with practical simulation.     

Information Propagation through Opportunistic Communication in Mobile Social Networks

At present, people can communicate with each other through short range communication technologies (Bluetooth, WiFi, etc.) installed in their smart terminals. Due to limited communication range, communication is opportunistic, and mobile social networks formed by such technologies can be seen as delay tolerant networks (DTN). This paper presents a theoretical framework to evaluate the performance of information propagation in such network based on ODE equations. This framework can evaluate the impact of peoples?? many behaviors. For example, people may not want to help others because of their selfish nature. In addition, peoples who are not interested in the message may not receive the message at all, but they become to be interested in the message later. On the other hand, people may discard the message after they used it. We check the accuracy of our model through simulations based on both synthetic and real motion traces (the average deviation is not bigger than 5.09?%). Numerical results show that peoples?? behaviors really have certain impact on the performance of information propagation. For example, if the selfish level is bigger, some persons cannot obtain message at all. If peoples discard message with bigger probability, above result may also appear.     

部分连接Ad-hoc网络路由算法的研究

针对部分连接Ad-hoc网络,引入定位技术,提出基于存储-寻找-移动-转发选路策略的主动式路由机制,并且设计两种方案使节点的运动轨迹最优:有数据发送的节点主动向目的节点移动或者依靠一个或多个中间节点接力传递数据.试验结果表明,这种路由机制在部分连接的Ad-hoc网络中实现了数据传输,并有效的提高了数据到达率.     

基于网络模体的移动社会网络信息可控传播方法

移动社会网络中的信息传播具有突发性、多元性、偏差性等特点,使得相关话题和事件能够在短时间内形成强大的网络和社会舆论场,这有可能被恶意用户利用来散布谣言,给网络环境带来了恶劣的影响。针对这一问题,该文提出一种基于网络模体的信息可控传播方法。首先,提出多实体的竞争性独立级联模型(MCIC),该模型在信息竞争扩散理论的基础上,首次结合社会网络层用户的社会属性,来感知恶意信息并控制信息传播。其次,该文定义了控制信息流模体(CIFM),并选择出具有可控传播功能的关键网络模体,设计其在通信层的高效可控传播算法。最后,通过理论推导证明了该文方法具有收敛性。仿真实验表明,与其他方法相比,所提方法不仅在信息传播中最大感染时间和平均感染时间上更有优势,而且在控制信息传播方面的效果也是最好的。     

移动自组网上结构化P2P网络Churn问题分析

分析研究了在三种用户行为的指数分布模型、Pareto分布模型和Weibull分布模型下,Churn问题对移动自组网上结构化P2P网络性能的影响.仿真实验研究表明,影响结构化P2P网络在移动自组网上工作性能的主要因素是节点会话时长、网络规模和节点密度、网络层路由协议以及节点移动性,并分析了这些主要因素之间的相互关系.     

Stochastic Properties of Mobility Models in Mobile Ad Hoc Networks

The stochastic model assumed to govern the mobility of nodes in a mobile ad hoc network has been shown to significantly affect the network's coverage, maximum throughput, and achievable throughput-delay trade-offs. In this paper, we compare several mobility models, including the random walk, random waypoint, and Manhattan models on the basis of the number of states visited in a fixed time, the time to visit every state in a region, and the effect of the number of wandering nodes on the time to first enter a set of states. These metrics for a mobility model are useful for assessing the achievable event detection rates in surveillance applications where wireless-sensor-equipped vehicles are used to detect events of interest in a city. We also consider mobility models based on Correlated Random Walks, which can account for time dependency, geographical restrictions, and nonzero drift. We demonstrate that these models are analytically tractable by using a matrix-analytic approach to derive new, closed-form results in both the time and transform-domains for the probability that a node is at any location at any time for both semi-infinite and finite 1D lattices. We also derive first entrance time distributions for these walks. We find that a correlated random walk 1) covers more ground in a given amount of time and takes a smaller amount of time to cover an area completely than a random walk with the same average transition rate, 2) has a smaller first entrance time to small sets of states than the random waypoint and random walk models, and 3) leads to a uniform distribution of nodes (except at the boundaries) in steady state.