A technique to improve network lifetime in mobile ad hoc networks

Energy is an important issue in mobile ad hoc networks (MANETs), and different energy‐aware routing mechanisms have been proposed to minimize the energy consumption in MANETs. Most of the energy‐aware routing schemes reported in the literature have considered only the residual battery capacity as the cost metric in computing a path. In this paper, we have proposed, an energy‐aware routing technique which considers the following parameters: (i) a cost metric, which is a function of residual battery power and energy consumption rate of participating nodes in path computation; (ii) a variable transmission power technique for transmitting data packets; and (iii) To minimize the over‐utilization of participating nodes, a limit is set on the number of paths that can be established to a destination through a participating node. The proposed scheme is simulated using Qualnet 4.5 simulator, and compared with Ad hoc On‐Demand Distance Vector (AODV) and Lifetime Enhancement Routing (LER). We observed that the proposed scheme performs better in terms of network lifetime and energy consumption. Copyright © 2014 John Wiley & Sons, Ltd.     

OLSR performance measurement in a military mobile ad hoc network

Wireless ad hoc networks are autonomous, self-configurating and adaptive. Thus, such networks are excellent candidates for military tactical networks, where their ability to be operational rapidly and without any centralized entity is essential. As radio coverage is usually limited, multihop routing is often needed; this is achieved by an ad hoc routing protocol supporting nodes mobility. In this paper, we present performance measurements of the Optimized Link State Routing (OLSR) routing protocol, having the status of IETF RFC. The measurements are performed at CELAR site on a platform representative of military scenarios in urban areas. This platform consists of ten routers, eight PDAs and laptops using a IEEE 802.11b radio interface and implementing OLSR v7. Some nodes are mobile within vehicles. The emphasis of the measurements is on the performance of the network (route repair, network convergence speed, user traffic performance) in presence of this mobility.     

Security in vehicular ad hoc networks [security in mobile ad hoc]

Vehicular communication networking is a promising approach to facilitating road safety, traffic management, and infotainment dissemination for drivers and passengers. One of the ultimate goals in the design of such networking is to resist various malicious abuses and security attacks. In this article we first review the current standardization process, which covers the methods of providing security services and preserving driver privacy for wireless access in vehicular environments (WAVE) applications. We then address two fundamental issues, certificate revocation and conditional privacy preservation, for making the standards practical. In addition, a suite of novel security mechanisms are introduced for achieving secure certificate revocation and conditional privacy preservation, which are considered among the most challenging design objectives in vehicular ad hoc networks.     

Future trust management framework for mobile ad hoc networks [security in mobile ad hoc]

In mobile ad hoc networks nodes should collaborate with each other to support the functions of the network. The trust management framework, which evaluates the trust of participating nodes, is used to force nodes to cooperate in a normal way. We make an effort to design a robust and attack-resistant trust management framework for the future. In this article we describe the vulnerabilities of and possible attacks on existing frameworks. An objective trust management framework is proposed to overcome these vulnerabilities. We provide a theoretical basis and skeleton for this framework. The performance evaluation and security analysis are provided showing the effectiveness and robustness of the OTMF compared with existing frameworks.     

移动Ad Hoc网络路由协议性能仿真对比分析

基于OPNET仿真平台,通过考察节点移动速度、节点移动暂停时间、节点密度和发包间隔对路由协议性能的影响,全面地研究了移动AdHoe网络中典型路由协议的性能。为了公平地对比按需驱动类路由协议和表驱动类路由协议,采用了归一化路由负载作为路由开销的性能指标,最后对3个方面的路由协议性能进行对比和分析。结果表明,仿真结果和理论分析是相符的,因此采用的方法是正确的。     

SPREAD: Improving network security by multipath routing in mobile ad hoc networks

We propose and investigate the SPREAD scheme as a complementary mechanism to enhance secure data delivery in a mobile ad hoc network. The basic idea is to transform a secret message into multiple shares, and then deliver the shares via multiple paths to the destination so that even if a certain number of message shares are compromised, the secret message as a whole is not compromised. We present the overall system architecture and discuss three major design issues: the mathematical model for the generation and reconstruction of the secret message shares, the optimal allocation of the message shares onto multiple paths in terms of security, and the multipath discovery techniques in a mobile ad hoc network. Our extensive simulation results justify the feasibility and the effectiveness of the SPREAD approach.

HOPNET: A hybrid ant colony optimization routing algorithm for mobile ad hoc network

Mobile ad hoc network (MANET) is a group of mobile nodes which communicates with each other without any supporting infrastructure. Routing in MANET is extremely challenging because of MANETs dynamic features, its limited bandwidth and power energy. Nature-inspired algorithms (swarm intelligence) such as ant colony optimization (ACO) algorithms have shown to be a good technique for developing routing algorithms for MANETs. Swarm intelligence is a computational intelligence technique that involves collective behavior of autonomous agents that locally interact with each other in a distributed environment to solve a given problem in the hope of finding a global solution to the problem. In this paper, we propose a hybrid routing algorithm for MANETs based on ACO and zone routing framework of bordercasting. The algorithm, HOPNET, based on ants hopping from one zone to the next, consists of the local proactive route discovery within a node’s neighborhood and reactive communication between the neighborhoods. The algorithm has features extracted from ZRP and DSR protocols and is simulated on GlomoSim and is compared to AODV routing protocol. The algorithm is also compared to the well known hybrid routing algorithm, AntHocNet, which is not based on zone routing framework. Results indicate that HOPNET is highly scalable for large networks compared to AntHocNet. The results also indicate that the selection of the zone radius has considerable impact on the delivery packet ratio and HOPNET performs significantly better than AntHocNet for high and low mobility. The algorithm has been compared to random way point model and random drunken model and the results show the efficiency and inefficiency of bordercasting. Finally, HOPNET is compared to ZRP and the strength of nature-inspired algorithm is shown.     

An immunity-based security architecture for mobile ad hoc networks

This paper focuses on investigating immunological principles in designing a multi-agent security architecture for intrusion detection and response in mobile ad hoc networks. In this approach, the immunity-based agents monitor the situation in the network. These agents can take appropriate actions according to the underlying security policies. Specifically, their activities are coordinated in a hierarchical fashion while sensing, communicating, decision and generating responses. Such an agent can learn and adapt to its environment dynamically and can detect both known and unknown intrusions. The proposed intrusion detection architecture is designed to be flexible, extendible, and adaptable that can perform real-time monitoring. This paper provides the conceptual view and a general framework of the proposed system. In the end, the architecture is illustrated by an example to show it can prevent the attack efficiently.     

Improved ID-based security framework for ad hoc network

As mobile devices with wireless communication capacity become more and more popular, the study on ad hoc networks that offer convenient infrastructure-free communication has arose the attention from both the academic and the industry. However, the previous security schemes proposed for ad hoc networks either suffer from the structure support problems or have security flaws. This paper examines the weaknesses of a Bohio–Miri’s recent work, and then proposes our new schemes to enhance the security and the performance. The security of the proposed protocols is proved in the random oracle model.     

基于粒子滤波步行长度预测的移动ad hoc网络路由算法

针对移动ad hoc网络拓扑结构变化大、路由复杂度高、数据传输性能低等问题,提出了一种新的移动通信系统自适应路由算法。为了使得网络拓扑结构更接近移动网络间歇性连接的特点,该算法在网络结构上采用了一种改进的Levy Walk移动模型。采用一种粒子滤波步行长度预测的方法,通过蒙特卡罗抽样得到递归贝叶斯滤波器,并在粒子滤波后进行步行长度预测,确定消息的副本数量,从而减少由于节点转发过多消息副本带来的能量消耗量,提高消息的传递效率。实验仿真结果表明：与基于改进蚁群优化和利润优化模型的路由算法相比,该算法的消息传递成功率分别提高了0.08和0.04,节点平均能量效率提高了17.9%和13.4%,在提升数据传输成功率和节能上具有较好效果。     

An adaptive algorithm for connecting mobile ad hoc network to Internet with unidirectional links supported

The performance of Internet connectivity is degraded dramatically by blind rebroadcast of gateway discovery packets when obvious unidirectional links are ignored. To overcome this problem, an effective adaptive gateway discovery algorithm for connecting mobile ad hoc network to Internet with unidirectional links supported is proposed in this paper. On the basis of modification for ad hoc on-demand distance vector (AODV), through rebroadcasting the gateway discovery messages and gateway advertisement messages, both of which are extended with local connection information, unidirectional links are successfully removed from global route computations and Internet connectivity is simultaneously enhanced. Furthermore, an adaptive Internet working scheme is adopted to provide the best coverage of gateway advertisement according to dynamically adjusting broadcast range and sending interval of gateway advertisement messages in terms of network conditions. Simulation results show that the proposed hybrid Internet connectivity algorithm can provide better connectivity performance due to avoiding unidirectional links effectively with reasonable overhead.     

Detecting and avoiding wormhole attacks in wireless ad hoc networks [security in mobile ad hoc]

A particularly severe attack on routing protocols in ad hoc networks is the so-called worm- hole attack in which two or more colluding attackers record packets at one location, and tunnel them to another location for replay at that remote location. When this attack targets specifically routing control packets, the nodes that are close to the attackers are shielded from any alternative routes with more than one or two hops to the remote location. All routes are thus directed to the wormhole established by the attackers. In the optimized link state routing protocol, if a wormhole attack is launched during the propagation of link state packets, the wrong link information percolates throughout the network, leading to routing disruption. In this article we devise an efficient method to detect and avoid wormhole attacks in the OLSR protocOLSR protocolol. This method first attempts to pinpoint links that may potentially be part of a wormhole tunnel. Then a proper wormhole detection mechanism is applied to suspicious links by means of an exchange of encrypted probing packets between the two supposed neighbors (endpoints of the wormhole). The proposed solution exhibits several advantages, among which are its nonreliance on any time synchronization or location information, and its high detection rate under various scenarios.     

Performance of PKI-based security mechanisms in mobile ad hoc networks

Security for ad hoc network environments has received a lot of attention as of today. Previous work has mainly been focussing on secure routing, fairness issues, and malicious node detection. However, the issue of introducing and conserving trust relationships has received considerably less attention. In this article, we present a scalable method for the use of public key certificates and their revocation in mobile ad hoc networks (MANETs). With the LKN-ad hoc security framework (LKN-ASF) a certificate management protocol has been introduced, bringing PKI technology to MANETs. In addition a performance analysis of two different revocation approaches for MANETs will be presented.     

SCAN: self-organized network-layer security in mobile ad hoc networks

Protecting the network layer from malicious attacks is an important yet challenging security issue in mobile ad hoc networks. In this paper, we describe SCAN, a unified network-layer security solution for such networks that protects both routing and data forwarding operations through the same reactive approach. SCAN does not apply any cryptographic primitives on the routing messages. Instead, it protects the network by detecting and reacting to the malicious nodes. In SCAN, local neighboring nodes collaboratively monitor each other and sustain each other, while no single node is superior to the others. SCAN also adopts a novel credit strategy to decrease its overhead as time evolves. In essence, SCAN exploits localized collaboration and information cross-validation to protect the network in a self-organized manner. Through both analysis and simulation results, we demonstrate the effectiveness of SCAN even in a highly mobile and hostile environment.     

Stable routing algorithm for mobile ad hoc networks using mobile agent

Wireless ad hoc networks are growing important because of their mobility, versatility, and ability to work with fewer infrastructures. The mobile ad hoc network is an autonomous system consisting of mobile nodes connected with wireless links. Establishing a path between two nodes is a complex task in wireless networks. It is still more complex in the wireless mobile ad hoc network because every node is no longer as an end node and an intermediate node. In this paper, it focuses on design of connectionless routing protocol for the wireless ad hoc networks based on the mobile agent concept. The proposed model tries to discover the best path taking into consideration some concerns like bandwidth, reliability, and congestion of the link. The proposed model has been simulated and tested under various wireless ad hoc network environments with the help of a different number of nodes. The results demonstrate that the proposed model is more feasible for providing reliable paths between the source and destination with the minimum control message packets over the network. It has delivered more number of packets to the destination over the network. Copyright © 2012 John Wiley & Sons, Ltd.     

Eventually Byzantine Agreement on CDS-based mobile ad hoc network

Reliability is an important research topic in the study of distributed systems. Under many circumstances, a healthy processor in a distributed system needs to reach a common agreement before performing some special tasks even if the faults exist. In order to achieve fault-tolerance in distributed systems, one must deal with the Byzantine Agreement (BA) problem. Most BA problem require all the healthy processors to obtain an agreement at the same round, this kind of agreement is called an Immediate Byzantine Agreement (IBA). Another kind of agreement, Eventual Byzantine Agreement (EBA), allows its participants to reach a common agreement at different rounds when the f_act < f_p (f_act is the number of actual arbitrary faulty processors; f_p is the number of tolerate arbitrary faulty processors). However, the traditional EBA problem is solved in well-defined networks, but the Mobile Ad hoc NETworks (MANETs) are increasing in popularity. Therefore, EBA problem is revisited under dual failure mode (processors and transmission media) in the MANET. The proposed protocol, Early Dual Agreement Protocol (EDAP), can achieve agreement while tolerating the maximum number of faulty processors and transmission media in a MANET by using the minimum number of message exchanges. Furthermore, our protocol can manage and organize the network efficiently even if the processors move around the network.     

Efficient modeling of network flooding performance with proactive retransmissions in mobile ad hoc networks

Wireless Networks - Network flooding is the key mechanism designed to reach mobile nodes and disseminate the information in MANETs. Increasing the number of floods is a good way to improve...     

Secure way routing protocol for mobile ad hoc network

Mobile adhoc network is dynamic in nature and it operates completely in an infrastructure-less environment. It discovers the way routes dynamically to reach the destination. Securing a dynamic way route, which is not known before establishing communication, is always a challenge in the mobile ad hoc network. Most of the existing secure routing protocols target to evade specific type of attacks or malicious behaviour of the nodes or networks. We propose a novel secure way routing protocol for securing the dynamic way routes in MANET. It provides a unique session key for each route to secure the data communication. Moreover, it authenticates the data packets using asymmetric cryptography and secures the routing field message using two-way asymmetric cryptography. The proposal is implemented and tested for assessing the protocol’s performance. We have also compared the protocol with the other secure routing protocols for evaluating its performance.     

Self-regulating network utilization in mobile ad hoc wireless networks

In mobile ad hoc wireless LANs, it is very difficult to maintain a targeted network utilization due to the time-varying nature of the contention-based medium access control protocol and the lack of a central control. Furthermore, previous research has been mainly focusing on the aspect of optimizing the performance at each station. But doing so may result in a very low overall network utilization. Therefore, self-regulating network utilization is very important to provide quality-of-service (QoS) in mobile ad hoc wireless networks. Through self-disciplining its own behaviors locally, each station will optimize its protocol parameters to meet the targeted overall network utilization, which is very important for QoS provisioning to multimedia services. This paper proposes and evaluates a fully distributed scheme for each station to self-regulate its behaviors through adapting the local protocol parameters to meet the targeted overall network utilization with the changes in the network environment such as the number of stations and channel quality.