Distributed intrusion detection for mobile ad hoc networks

Mobile ad hoc networking （MANET） has become an exciting and important technology in recent years, because of the rapid proliferation of wireless devices. Mobile ad hoc networks is highly vulnerable to attacks due to the open medium, dynamically changing network topology, cooperative algorithms, and lack of centralized monitoring and management point. The traditional way of protecting networks with firewalls and encryption software is no longer sufficient and effective for those features. A distributed intrusion detection approach based on timed automata is given. A cluster-based detection scheme is presented, where periodically a node is elected as the monitor node for a cluster. These monitor nodes can not only make local intrusion detection decisions, but also cooperatively take part in global intrusion detection. And then the timed automata is constructed by the way of manually abstracting the correct behaviours of the node according to the routing protocol of dynamic source routing （DSR）. The monitor nodes can verify the behaviour of every nodes by timed automata, and validly detect real-time attacks without signatures of intrusion or trained data. Compared with the architecture where each node is its own IDS agent, the approach is much more efficient while maintaining the same level of effectiveness. Finally, the intrusion detection method is evaluated through simulation experiments.

Multipath Source Self Repair Routing Algorithm for Mobile Ad Hoc Networks

A multipath source self repair routing (MSSRR) algorithm for mobile ad hoc networks is proposed. By using multiple paths which can be repaired by themselves to transmit packets alternately, the network's load is balanced, the link state in the network can be checked in time, the number of the times the route discovery mechanism starts is decreased. If only one route which will be broken can be used to transmit the packets, the route discovery mechanism is restarted.The algorithm is implemented on the basis of dynamic source routing (DSR). The effect of MSSRR on lifetime of the access from the source to the destination and the overhead is discussed. Compared with the performance of DSR,it can be seen that the algorithm can improve the performance of the network obviously and the overhead almost does not increase if the average hop count is larger.

An Ant Colony Algorithm Based Congestion Elusion Routing Strategy for Mobile Ad Hoc Networks

A critical challenge for mobile ad hoc networks is the design of efficient routing protocols which are able to provide high bandwidth utilization and desired fairness in mobile wireless environment without any fixed communication establishments. Although extensive efforts have already been devoted to providing optimization based distributed congestion elusion strategy for efficient bandwidth utilization and fair allocation in both wired and wireless networks,a common assumption therein is the fixed link capacities,which will unfortunately limit the application scope in mobile ad hoc networks where channels keep changing. In this paper,an effective congestion elusion strategy is presented explicitly based on ant colony algorithm for mobile ad hoc networks, which will explore the optimal route between two nodes promptly,meanwhile forecast congestion state of the link. Accordingly,a new path will be found rapidly to have the flow spread around to relieve the congestion degree. Compared with OLSR,the strategy proposed will greatly reduce the packet loss ratio and the average end-to-end delay at the same time,which illustrate that it will make use of networking resource effectively.

A distributed adaptive multi-hop certification authority schemefor mobile Ad Hoc networks

This paper theoretically analyzes a deficiency of the existing scheme, and proposes a distributed multi-hop certification authority scheme for mobile Ad Hoc networks. In our design, we distribute the certification authority functions through a threshold secret sharing mechanism, in which each node holds a secret share and multiple nodes jointly provide complete services. Certification authority is not limited in a local neighborhood but can be completed within multi-hop location. In addition, we replace broadcast by multicast to improve system performance and reduce communication overhead. This paper resolves some technical problems of ubiquitous certification authority services, and presents a wieldy multi-hop certification authority algorithm. Simulation results confirm the availability and effectiveness of our design.

History-Based Backoff Algorithms for Mobile Ad Hoc Networks

Mobile Ad hoc Network (MANET) is a wireless network consisting of mobile devices (laptops, smart phones, etc.) that move and communicate with each other without the use of any existing network infrastructure or centralized server to avoid collisions which have negative effects on the performance of the network. Access to the shared media is controlled by a Backoff algorithm that is a part of the Media Access Protocol. In this paper, we improve the History Based Probabilistic Backoff (HPPB) algorithm by modifying the increment/decrement behavior of the Contention Window to introduce History Based Increment Backoff (HBIB) algorithm which outperforms HBPB in terms of throughput and end-to-end delay with various numbers of nodes and different traffic loads.

Anonymous multipath routing protocol based on secret sharing in mobile ad hoc networks

Because the intrinsic characteristics of mobile ad hoc networks（MANETs） cause several vulnerabilities,anonymous routing protocols attract much more attention in secure mobile ad hoc networks for the purposes of security and privacy concerns.Until recently,lots of anonymous routing protocols have been proposed.However,most of them are single path or use one path at a time,and the multipath schemes can not thwart both the passive attacks and active attacks simultaneously.Thus an anonymous multipath routing protocol based on secret sharing is proposed.The protocol provides identity anonymity,location anonymity,data and traffic anonymity by employing cryptograph technology and secret sharing in MANET communication process.Meanwhile,a hash function is introduced to detect active attacks in the data transmission process.The protocol can effectively thwart various passive attacks and reduce the successful probability of active attacks（such as interception and physical destroy attacks）.Simulation results show that the proposed scheme provides a reasonably good level of network security and performance.

Performance analysis of mobile ad hoc networks under flooding attacks

Due to their characteristics of dynamic topology, wireless channels and limited resources, mobile ad hoc networks are particularly vulnerable to a denial of service （DoS） attacks launched by intruders. The effects of flooding attacks in network simulation 2 （NS2） and measured performance parameters are investigated, including packet loss ratio, average delay, throughput and average number of hops under different numbers of attack nodes, flooding frequency, network bandwidth and network size. Simulation results show that with the increase of the flooding frequency and the number of attack nodes, network performance sharply drops. But when the frequency of flooding attacks or the number of attack nodes is greater than a certain value, performance degradation tends to a stable value.

Analysis of reactive routing protocols for mobile ad hoc networks in Markov models

Mobile ad hoc networks （MANETs） have become a hot issue in the area of wireless networks for their non-infrastructure and mobile features. In this paper, a MANET is modeled so that the length of each link in the network is considered as a birthdeath process and the space is reused for n times in the flooding process, which is named as an n-spatiai reuse birth-death model （n-SRBDM）. We analyze the performance of the network under the dynamic source routing protocol （DSR） which is a famous reactive routing protocol. Some performance parameters of the route discovery are studied such as the probability distribution and the expectation of the flooding distance, the probability that a route is discovered by a query packet with a hop limit, the probability that a request packet finds a τ-time-valid route or a symmetric-valid route, and the average time needed to discover a valid route. For the route maintenance, some parameters are introduced and studied such as the average frequency of route recovery and the average time of a route to be valid. We compare the two models with spatial reuse and without spatial reuse by evaluating these parameters. It is shown that the spatial reuse model is much more effective in routing.

Ants-Based On-Demand Routing Algorithm for Mobile Ad Hoc Networks

An ants-based on-demand routing algorithm （AORA） specialized for mobile ad hoc networks is proposed. AORA measures the network＇s traffic information including delivery time, route energy etc. by the continuous delivery of data packets, then calculates the compositive parameter for each route which can be seen as the stigmity and uses it to choose the comparatively optimal route in real time. To adjust the weight of each traffic information, the algorithm can meet the different demand of the network＇s user. Multipath source self repair routing （MSSRR） algorithm and dynamic source routing （DSR） can be seen as the special samples of AORA. The routing overhead is not increased in this algorithm. By using simulation, it can be seen that the performance of AORA is better than that of DSR in all scenarios obviously, especially the delivery fraction is increased by more than 100 96.

Void Aware Position Based Opportunistic Routing for QoS in Mobile Ad Hoc Networks

The unique anywhere, anytime wireless communication support offers, tremendous potential for the next generation of applications in a Mobile Ad-hoc Network (MANET). The Quality of Service (QoS) has been the ever demanding task of wireless communication to satisfy the application requirements. Geographical routing employs a greedy forwarding technique to deliver the packets to the destination and to owe the communication void, it fails to render the expected level of QoS. Opportunistic routing technique effectively utilizes the advantages of broadcasting nature of the wireless medium and selects a set of forwarding candidates instead of relying on a greedy node. To improve the efficiency of QoS routing in sparse and highly dynamic network topology, this paper proposes the Void-Aware Position based Opportunistic Routing (VAPOR). The VAPOR maintains 2-hop neighbor information to take a routing decision, but it is limited to 1-hop information when the node density is high. It efficiently balances the storage overhead and communication delay due to void and it increases the network throughput even under a sparse network. To provide a certain assurance level for packet reachability, VAPOR decides the potential forwarders based on the forwarding probability that measures link stability, capacity, and connectivity factor. It adaptively favors a path that avoids frequent link failure and unreliable link usage. By limiting the propagation area of duplicate packets, VAPOR reduces wastage of network resources, and ittakes the advantage of concurrent batch forwarding to avoid further duplication and unnecessary delay.

QoS Support in TDMA-Based Mobile Ad Hoc Networks

Mobile ad hoc networks （MANETs） are gaining a lot of attention in research lately due to their importance in enabling mobile wireless nodes to communicate without any existing wired or predetermined infrastructures. Furthermore, in order to support the growing need for multimedia and realtime applications, quality of service （QoS） support by the networking protocol is required. Several important QoS parameters that are needed by such applications can be identified. They include bandwidth, end-to-end delay, delay jitter, and bit error rate. A good amount of research has been developed in this area covering different issues and challenges such as developing routing protocols that support bandwidth reservation and delay management. In this paper, the current state of research for QoS support in TDMA-based MANETs at different layers of the networking model is presented and categorized. In addition, the current issues and future challenges involved in this exciting area of research are also included.

A fuzzy trust-based routing model for mitigating the misbehaving nodes in mobile ad hoc networks

Purpose–Security is one of the major challenges in the design and implementation of protocols for mobile ad hoc networks(MANETs).In such systems,the cooperation between nodes is one of the important principles being followed in the current research works to formulate various security protocols.Many existing works assume that mobile nodes will follow prescribed protocols without deviation.However,this is not always the case,because these networks are subjected to a variety of malicious attacks.Since there are various models of attack,trust routing scheme can guarantee security and trust of the network.The purpose of this paper is to propose a novel trusted routing model for mitigating attacks in MANETs.Design/methodology/approach–The proposed model incorporates the concept of trust into the MANETs and applies grey relational analysis theory combined with fuzzy sets to calculate a node’s trust level based on observations from neighbour nodes’trust level,these trust levels are then used in the routing decision-making process.Findings–In order to prove the applicability of the proposed solution,extensive experiments were conducted to evaluate the efficiency of the proposed model,aiming at improving the network interaction quality,malicious node mitigation and enhancements of the system’s security.Originality/value–The proposed solution in this paper is a new approach combining the fundamental basics of fuzzy sets with the grey theory,where establishment of trust relationships among participating nodes is critical in order to enable collaborative optimisation of system metrics.Experimental results indicate that the proposed method is useful for reducing the effects of malicious nodes and for the enhancements of system’s security.

A distributed synchronous reservation multiple access control protocol for mobile Ad hoc networks

This study proposes a new multiple access con-trol protocol named distributed synchronous reservation mul-tiple access control protocol,in which the hidden and exposed terminal problems are solved,and the quality of service(QoS)requirements for real-time traffic are guaranteed.The protocol is founded on time division multiplex address and a different type of traffic is assigned to different priority,according to which a node should compete for and reserve the free slots in a different method.Moreover,there is a reservation acknowledgement process before data transmit in each reserved slot,so that the intruded terminal problem is solved.The throughput and average packets drop probability of this protocol are analyzed and simulated in a fully connected network,the results of which indicate that this protocol is efficient enough to support the real-time traffic,and it is more suitable to MANETs.

TCP Issues in Mobile Ad Hoc Networks： Challenges and Solutions

Mobile ad hoc networks （MANETs） are a kind of very complex distributed communication systems with wireless mobile nodes that can be freely and dynamically self-organized into arbitrary and temporary network topologies. MANETs inherit several limitations of wireless networks, meanwhile make new challenges arising from the specificity of MANETs, such as route failures, hidden terminals and exposed terminals. When TCP is applied in a MANET environment, a number of tough problems have to be dealt with. In this paper, a comprehensive survey on this dynamic field is given. Specifically, for the first time all factors impairing TCP performance are identified based on network protocol hierarchy, i.e., lossy wireless channel at the physical layer; excessive contention and unfair access at the MAC layer; frail routing protocol at the network layer, the MAC layer and the network layer related mobile node; unfit congestion window size at the transport layer and the transport layer related asymmetric path. How these factors degrade TCP performance is clearly explained. Then, based on how to alleviate the impact of each of these factors listed above, the existing solutions are collected as comprehensively as possible and classified into a number of categories, and their advantages and limitations are discussed. Based on the limitations of these solutions, a set of open problems for designing more robust solutions is suggested.

AHBP: An Efficient Broadcast Protocol forMobile Ad Hoc Networks

Broadcast is an important operation in many network protocols. It is utilized to discover routes to unknown nodes in mobile ad hoc networks (MANETs) and is the key factor in scaling on-demand routing protocols to large networks. This paper presents the Ad Hoc Broadcast Protocol (AHBP) and its performance is discussed. In the protocol, messages are only rebroadcast by broadcast relay gateways that constitute a connected dominating set of the network. AHBP can efficiently reduce the redundant messages which make flooding-like protocols perform badly in large dense networks. Simulations are conducted to determine the performance characteristics of the protocol. The simulation results have shown excellent reduction of broadcast redundancy with AHBP. It also contributes to a reduced level of broadcast collision and congestion.

Geographic Drone-based Route Optimization Approach for Emergency Area Ad-Hoc Network

Wireless sensor Mobile ad hoc networks have excellent potential in moving and monitoring disaster area networks on real-time basis.The recent challenges faced in Mobile Ad Hoc Networks(MANETs)include scalability,localization,heterogeneous network,self-organization,and self-sufficient operation.In this background,the current study focuses on specially-designed communication link establishment for high connection stability of wireless mobile sensor networks,especially in disaster area network.Existing protocols focus on location-dependent communications and use networks based on typically-used Internet Protocol(IP)architecture.However,IP-based communications have a few limitations such as inefficient bandwidth utilization,high processing,less transfer speeds,and excessive memory intake.To overcome these challenges,the number of neighbors(Node Density)is minimized and high Mobility Nodes(Node Speed)are avoided.The proposed Geographic Drone Based Route Optimization(GDRO)method reduces the entire overhead to a considerable level in an efficient manner and significantly improves the overall performance by identifying the disaster region.This drone communicates with anchor node periodically and shares the information to it so as to introduce a drone-based disaster network in an area.Geographic routing is a promising approach to enhance the routing efficiency in MANET.This algorithm helps in reaching the anchor(target)node with the help of Geographical Graph-Based Mapping(GGM).Global Positioning System(GPS)is enabled on mobile network of the anchor node which regularly broadcasts its location information that helps in finding the location.In first step,the node searches for local and remote anticipated Expected Transmission Count(ETX),thereby calculating the estimated distance.Received Signal Strength Indicator(RSSI)results are stored in the local memory of the node.Then,the node calculates the least remote anticipated ETX,Link Loss Rate,and information to the new location.Freeway Heuristic algorithm improves the data speed,efficiency and determines the path and optimization problem.In comparison with other models,the proposed method yielded an efficient communication,increased the throughput,and reduced the end-to-end delay,energy consumption and packet loss performance in disaster area networks.

Link reliability based hybrid routing for tactical mobile ad hoc network

Tactical mobile ad hoc network （MANET） is a collection of mobile nodes forming a temporary network, without the aid of pre-established network infrastructure. The routing protocol has a crucial impact on the network performance in battlefields. Link reliability based hybrid routing （LRHR） is proposed, which is a novel hybrid routing protocol, for tactical MANET. Contrary to the traditional single path routing strategy, multiple paths are established between a pair of source-destination nodes. In the hybrid routing strategy, the rate of topological change provides a natural mechanism for switching dynamically between table-driven and on-demand routing. The simulation results indicate that the performances of the protocol in packet delivery ratio, routing overhead, and average end-to-end delay are better than the conventional routing protocol.

Calculation and Analysis of Destination Buffer for Multimedia Service in Mobile Ad Hoc Network

Jitter is one of the most important issues for multimedia real time services in future mobile ad hoc networks（MANET）. A thorough theoretical analysis of the destination buffer for smoothing the jitter of the real time service in MANET is given. The theoretical results are applied in moderate populated ad hoc networks in our simulation, the simulation results show that by predicting and adjusting destination buffer in our way, Jitter will be alleviated in large part and this will contribute much to the quality of service （QOS） in MANET.

Genetic Algorithm Routing Protocol for Mobile Ad Hoc Network

Mobile ad hoc network(MANET)is a dynamically reconfigurable wireless network with time-variable infrastructure.Given that nodes are highly mobile,MANET’s topology often changes.These changes increase the difficulty in finding the routes that the packets use when they are routed.This study proposes an algorithm called genetic algorithm-based location-aided routing(GALAR)to enhance the MANET routing protocol efficiency.The GALAR algorithm maintains an adaptive update of the node location information by adding the transmitting node location information to the routing packet and selecting the transmitting node to carry the packets to their destination.The GALAR was constructed based on a genetic optimization scheme that considers all contributing factors in the delivery behavior using criterion function optimization.Simulation results showed that the GALAR algorithm can make the probability of packet delivery ratio more than 99%with less network overhead.Moreover,GALAR was compared to other algorithms in terms of different network evaluation measures.The GALAR algorithm significantly outperformed the other algorithms that were used in the study.

An Improved Spatially Aware Routing Algorithm for Mobile Ad Hoc Network in Inter-Vehicle Communication

A new algorithm called spatially aware routing algorithm with enhanced learning (SAREL) is proposed to guarantee the rationality of route selecting in inter-vehicle communication scenario. Firstly, the traffic model is discussed and set up by using Poisson distribution. Then we analyze the process of traffic evaluation with enhanced learning, and exploit movement estimation to assist state memorization. The improvement of algorithm is provided at last compared with our previous work. Simulation results show that SAREL algorithm could achieve better performance in packet delivery ratio, especially when network connection ratio is average. Key words mobile ad hoc network - spatially aware routing - enhanced learning CLC number TP 316 Foundation item: Supported by Open Laboratory Foundation by China Ministry of Education (TKLJ9903), Project CarTALK 2000 by the European Commission (IST-2000-28185) and Project FleetNet-Internet on the Road by the German Ministry of Education and Research (01AK025)Biography: HAN Lu (1974-), male, Ph. D candidate, research direction; distributed artificial intelligence.