Multi-hop Mobile Ad Hoc Networks Research Articles

Improving Bandwidth Utilization of Intermittent Links in Highly Dynamic Ad Hoc Networks

Non-uniform node densities occur and intermittent links exist in highly dynamic ad hoc networks. To fit these networks, researchers usually combine delay tolerant network (DTN) routing protocols and mobile ad hoc network (MANET) routing protocols. The DTN protocol separates end-to-end links into multiple DTN links, which consist of multi-hop MANET links. Determining how to arrange DTN links and MANET links from source to end and dealing with intermittent links are performance issues, because node density ranges from sparse to dense and MANET protocols are much lighter than DTN protocols. This paper presents HMDTN, an application-network cross-layer framework, to solve the previously mentioned issues. The application layer in HMDTN supports disrupt tolerance with a large data buffer while adjusting the routing table on the basis of the connection state of links (link is disrupted or recovered), which are collected by the network layer. As a result, HMDTN increases the bandwidth utilization of intermittent links without compromising the efficiency of the MANET protocol in a reliable network. The HMDTN prototype was implemented based on Bytewalla (a Java version of DTN2) and Netfilter-based AODV. Experiments on Android devices show that unlike AODV and Epidemic, HMDTN increases the bandwidth utilization of intermittent links with a negligible increase of network overhead. In particular, HMDTN maintains the network throughput as high as regular network conditions even if the network undergoes relatively long-term (dozens of seconds or few minutes) data link disruptions.

A Survey on the Application of Evolutionary Algorithms for Mobile Multihop Ad Hoc Network Optimization Problems

Evolutionary algorithms are metaheuristic algorithms that provide quasioptimal solutions in a reasonable time. They have been applied to many optimization problems in a high number of scientific areas. In this survey paper, we focus on the application of evolutionary algorithms to solve optimization problems related to a type of complex network like mobile multihop ad hoc networks. Since its origin, mobile multihop ad hoc network has evolved causing new types of multihop networks to appear such as vehicular ad hoc networks and delay tolerant networks, leading to the solution of new issues and optimization problems. In this survey, we review the main work presented for each type of mobile multihop ad hoc network and we also present some innovative ideas and open challenges to guide further research in this topic.

A Review of Artificial Immune System Based Security Frameworks for MANET

Mobile ad hoc networks (MANETs) are collections of wireless mobile devices that form a communication network with restricted broadcast range, limited resources and without fixed infrastructure. Routing is a critical function in multi-hop MANETs. At the same time, security in MANETs—especially routing security—presents a number of new and interesting challenges. Communication is achieved by relaying data along routes that are dynamically discovered and maintained through collaboration between the nodes. Advances in the field of artificial immune systems provide an opportunity to improve MANET security and performance. Artificial immune systems mimic the functionality of the human immune system wherein there is clear distinction between self and non self and this delineation is important in a MANET where there is no centralized management. The high level of protection provided to the human body by an evolved immune system can be applied as a security feature in MANET. The current security techniques proposed for MANET have varying degrees of success due to the dynamic nature of a MANET. This paper will review different strategies for the application of artificial immune systems to MANETs.

Reputed Packet Delivery Using Efficient Audit Misbehaviour Detection and Monitoring Method in Mobile Ad Hoc Networks

Abstract Safe and secure packet delivery multi-hop Mobile Ad hoc Network (MANET) is a challenging issue in today network environment. Hence, this paper aims in proposing to identify the misbehaving nodes and eliminating them from the packet transmissions in multi-hop mobile ad hoc networks. The effective and efficient Audit Misbehaviour Detection and Monitoring Method (AMDMM) that effectively monitors the both continuous and selective packet droppers to forward the packets through the reputed nodes. In this research work, the AMDMM integrates an identification of misbehaving nodes as well as the reputation management and trustworthy route discovery based on the behavioral audits. The AMDMM evaluates nodes’ behavior on a per-packet basis, without employing energy expensive overhearing techniques or intensive acknowledgment schemes. The Simulations are carried out successfully for eliminating the misbehaving nodes from the packet transmission and to establish the effective trustworthy routing path.

Public Protection and Disaster Relief Communication System Integrity: A Radio-Flexibility and Identity-Based Cryptography Approach

This article describes the application of radio flexibility for designing public protection and disaster relief (PPDR) wireless networks (NETs) in support of PPDR special needs, primary among which is information- transport resilience. It focuses further on the central role of mobile ad hoc NETs as the ground-segment element of the total architecture since the eventual solution must support rapid, robust, secure, scalable, and connectivityoriented communications. Research challenges associated with the provision of the necessary diversity at all communication layers as a means to such robustness are identified. Security aspects are addressed through a signature scheme based on identity key cryptography. Finally, a use case based on flexible multihop mobile ad hoc network (MANET) path establishment for harsh environments is presented.

A Novel Cognitive Method for Throughput Improvement of Mobile Multi-hop Ad Hoc Networks

We had previously defined a novel cognitive method for throughput improvement of IEEE 802.16j mobile multi-hop ad-hoc network which enables better management of the spectral access and buffer management of the nodes in the network. By this method we had minimized the packet loss ratio and improved the throughput of IEEE 802.16j network. In this study, a novel cognitive buffer management algorithm is proposed that arranges the packets stored in the buffers of the nodes in a probabilistic way and selects correct packet of the correct node to transmit first to provide fewer packet losses and also fewer average hop-counts for more throughputs. It is shown that the novel proposed buffer management algorithm provides about 19.45 % more throughput improvement (on average) with respect to the results evaluated by the buffer management algorithm used before (which was also shown to provide 12 % throughput improvement with respect to a First In First Out buffer management algorithm). All the results evaluated in this study are also confirmed by the results of analytical calculations, the results of the developed simulation program and the results evaluated in the literature.

Asynchronous Power Management Protocols With Minimum Duty Cycle and Maximum Adaptiveness for Multihop Ad Hoc Networks

IEEE 802.11 is currently the de facto medium access control (MAC) standard for mobile ad hoc networks (MANETs). However, in a multihop MANET, 802.11 power management may completely fail if stations are out of synchronization. To fix this problem, several papers have proposed various cyclic quorum-based power management (CQPM) protocols, which, however, may also fail if stations have different schedule repetition intervals (SRIs). Hence, adaptive CQPM protocols, namely, adaptive quorum-based energy conserving (AQEC) and hyper quorum system (HQS), were proposed to overcome this drawback. However, the duty cycles of AQEC and HQS are far from optimal. In this paper, we propose the optimal fully adaptive and asynchronous (OFAA) power management protocol for a multihop MANET, which has the following attractive features: 1) By means of factor-hereditary quorum space, the OFAA protocol guarantees that two neighboring stations can discover each other in bounded time, regardless of their clock difference and individual SRIs; 2) given the length of SRI, the duty cycle of a station reaches the theoretical minimum; 3) the number of tunable SRIs of every station reaches the theoretical maximum; 4) the time complexity of OFAA neighbor maintenance is O(1) ; 5) a cross-layer SRI adjustment scheme is proposed such that a station can adaptively tune the values of SRI to maximize energy conservation according to flow timeliness requirements. Both theoretical analysis and simulation results demonstrate that the OFAA protocol is much more energy efficient than AQEC and HQS protocols.

Impact of Nakagamim Fading Model on Multihop Mobile Ad Hoc Network

Impact of Nakagamim Fading Model on Multihop Mobile Ad Hoc Network

A Distributed Trust Management Framework for Detecting Malicious Packet Dropping Nodes in a Mobile Ad Hoc Network

In a multi-hop mobile ad hoc network (MANET) mobile nodes communicate with each other forming a cooperative radio network. Security remains a major challenge for these networks due to their features of open medium, dynamically changing topologies, reliance on cooperative algorithms, absence of centralized monitoring points, and lack of any clear lines of defense. Most of the currently existing security algorithms designed for these networks are insecure, in efficient, and have low detection accuracy for nodes' misbehaviour. In this paper, a new approach has been proposed to bring out the complementary relationship between key distribution and misbehaviour detection for developing an integrated security solution for MANETs. The redundancy of routing information in ad hoc networks is utilized to develop a highly reliable protocol that works even in presence of transient network partitioning and Byzantine failure of nodes. The proposed mechanism is fully co-operative, and thus it is more robust as the vulnerabilities of the election algorithms used for choosing the subset of nodes for cooperation are absent. Simulation results show the effectiveness of the proposed protocol.

Self-configured multipath routing using path lifetime for video-streaming services over Ad Hoc networks

The increasing spread of mobile nodes along with the technical advances in multi-hop MANETs (Mobile Ad hoc NETworks) makes this kind of networks an important type of access network of next generation. The demand of multimedia services from these networks is expected to significantly grow in the next years. Multimedia services, though, require the provision of Quality of Service (QoS). Nevertheless, the highly dynamic nature of MANETs, the energy constraints, the lack on centralized infrastructure and the variable link capacity, makes the QoS provision over MANETs a matter that challenges attention. These features make self-configuration and system adaptation questions of major importance when developing a QoS-aware framework. To tackle this issue, we have designed a-MMDSR (adaptive-Multipath Multimedia Dynamic Source Routing), a multipath routing protocol able to self-configure dynamically depending on the state of the network. The approach includes cross-layer techniques especially designed to improve the end-to-end performance of video-streaming services over IEEE 802.11e Ad Hoc networks. Besides, a straightforward analytical model to estimate the path error probability is presented. This model is used by the routing scheme to estimate the lifetime of the paths. In this way, proper proactive decisions can be made before the paths get broken. The model simplicity is appropriate for low capacity wireless devices. Simulation results validate the proposal and show the improvement on standard DSR (Dynamic Source Routing) and on a previous static version.

AMNP: ad hoc multichannel negotiation protocol with broadcast solutions for multi-hop mobile wireless networks

A multi-hop mobile ad hoc network (MANET) is generally configured as a peer-to-peer network with no centralised hubs or controllers that coordinate channel resources. Nodes in a MANET usually equip one single transceiver for data transmissions. However, the single transceiver architecture will cause a difficulty of being implemented in multichannel environment if the network transmission capacity would be improved by adopting parallel multichannel access. To solve this thorny problem, this study presents a distributed medium access control (MAC) layer protocol called ad hoc multichannel negotiation protocol (AMNP) for multichannel transmissions in the multi-hop MANET. Additionally, two problems, the multichannel hidden terminal problem and the multichannel broadcast transmission problem, caused by single transceiver operations in the multichannel environment, which have not been revealed in academia, is presented and solved in this study. Finally, an enhanced AMNP with channel scheduling (AMNP/s) scheme is introduced to improve the channel utilisation. The author show, via simulations, that AMNP/s provides a higher throughput compared to its single-channel counterpart by promoting simultaneous transmissions in different channels. Simulation results also show that AMNP/s derives higher performance than other multichannel transmission schemes that use multiple transceivers.

Cross Layer Optimized Video Streaming based on IEEE 802.11 Multi-rate over Multi-hop Mobile Ad Hoc Networks

In this paper, we present an effective cross layer optimized video streaming algorithm over multi-hop mobile ad hoc networks. The proposed algorithm selects the most efficient PHY (physical) mode and retransmission limit of WLAN (wireless local area network) multi-rate service at each node in a distributed way. The control parameters of the proposed algorithm (i.e. PHY mode and retransmission limit) are determined based on the available information at application, MAC, and physical layers in order to satisfy the end-to-end delay constraint and maintain packet loss rate in the tolerable range at the receiver. Finally, experimental results are provided to show the performance of the proposed algorithm.

A Framework for Detection of Selfishness in Multihop Mobile Ad Hoc Networks

The paper discusses the need for a fully-distributed selfishness detection mechanism dedicated for multihop wireless ad hoc networks which nodes may exhibit selfish forwarding behavior. The main contribution of this paper is an introduction to a novel approach for detecting and coping with the selfish nodes. Paper describes a new framework based on Dempster-Shafer theory-based selfishness detection framework (DST-SDF) with some mathematical background and simulation analysis.

Route duration modeling for mobile ad-hoc networks

In this paper, we present a model that estimates the time duration of routes formed by several intermediate nodes in mobile multi-hop ad-hoc networks. First, we analyze a 3-node route, where only the intermediate node is in movement while source and destination nodes remain static. From this case, we show how route duration is affected by the initial position of the intermediate node and the size of the region where it is located. We also consider a second case where all nodes of 3-node routes are mobile. Based on extensive analysis of these routes, we determine the PDF of route duration under two different mobility models. This PDF can be determined by either analytical or statistical methods. The main contribution of this paper is that the time duration of a route formed by N intermediate nodes can be accurately computed by considering the minimum route duration of a set of N routes of 3 nodes each. Simulation work was conducted using the NS-2 network simulator to verify the accuracy of the proposed model and to compare it with other proposals found in the literature. We show that our model is in better agreement with simulation results as compared with other models. Results from this work can be used to compute overhead signaling during route-maintenance of unicast and multicast routing protocols for mobile ad-hoc networks. Similarly, because route duration decreases with route length, this study can be used to scale the network size up/down.

Admission control schemes for 802.11-based multi-hop mobile ad hoc networks: a survey

Mobile ad hoc networks (MANETs) promise unique communication opportunities. The IEEE 802.11 standard has allowed affordable MANETs to be realised. However, providing quality of service (QoS) assurances to MANET applications is difficult due to the unreliable wireless channel, the lack of centralised control, contention for channel access and node mobility. One of the most crucial components of a system for providing QoS assurances is admission control (AC). It is the job of the AC mechanism to estimate the state of the network's resources and thereby to decide which application data sessions can be admitted without promising more resources than are available and thus violating previously made guarantees. Unfortunately, due to the aforementioned difficulties, estimating the network resources and maintaining QoS guarantees are non-trivial tasks. Accordingly, a large body of work has been published on AC protocols for addressing these issues. However, as far as it is possible to tell, no wide-ranging survey of these approaches exists at the time of writing. This paper thus aims to provide a comprehensive survey of the salient unicast AC schemes designed for IEEE 802.11- based multi-hop MANETs, which were published in the peer-reviewed open literature during the period 2000-2007. The relevant considerations for the design of such protocols are discussed and several methods of classifying the schemes found in the literature are proposed. A brief outline of the operation, reaction to route failures, as well as the strengths and weaknesses of each protocol is given. This enables patterns in the design and trends in the development of AC protocols to be identified. Finally, directions for possible future work are provided.

A Rebroadcast Area Based Broadcasting Scheme over Mobile Ad-Hoc Networks

In a multi-hop mobile ad-hoc network, broadcasting is an elementary operation to support many applications. Broadcasting by flooding may cause serious redundancy, contention, and collision in the network, which is referred to as the broadcast storm problem. Many broadcasting schemes have been proposed to give better performance than simple flooding in mobile ad-hoc network. How to decide whether rebroadcast or not also poses a dilemma between reachability and efficiency under different host densities. In this paper, we propose an enhanced broadcasting scheme, which can reduce rebroadcast packets without loss of reachability. Simulation results show that the proposed scheme offers better reachability and efficiency than other previous schemes.

SRDP: Secure route discovery for dynamic source routing in MANETs

Routing is a critical function in multi-hop mobile ad hoc networks (MANETs). A number of MANET-oriented routing protocols have been proposed, of which DSR is widely considered both the simplest and the most effective. At the same time, security in MANETs – especially, routing security – presents a number of new and interesting challenges. Many security techniques geared for MANETs have been developed, among which Ariadne is the flagship protocol for securing DSR. The focus of this work is on securing the route discovery process in DSR. Our goal is to explore a range of suitable cryptographic techniques with varying flavors of security, efficiency and robustness. The Ariadne approach (with TESLA), while very efficient, assumes loose time synchronization among MANET nodes and does not offer non-repudiation. If the former is not possible or the latter is desired, an alternative approach is necessary. To this end, we construct a secure route discovery protocol (SRDP) which allows the source to securely discover an authenticated route to the destination using either aggregated message authentication codes (MACs) or multi-signatures. Several concrete techniques are presented and their efficiency and security are compared and evaluated.

Distributed Correlative Power Control Schemes for MobileAd hocNetworks Using Directional Antennas

Medium access control (MAC) protocols simultaneously integrating transmission power (TP) control with directional antennas have the potential to enhance both energy savings and capacity throughput in wireless multihop Mobile Ad hoc NETworks (MANETs). In this paper, we present a model to calculate future interference in networks with directional antennas, and based on this model, we derive some relations that should exist between the required TP of RTS, CTS, DATA, and ACK frames for successful data packet delivery in MANETs based on the directional version of the IEEE 802.11 distributed coordination function. From these relations, we propose a distributed power control scheme. Furthermore, we show, via simulations, that the true potentials from the proposed control scheme cannot be shown due to the imperfection of the derived model. Based on these observations, we introduce another class of power control algorithm that instead deploys a prediction filter (Kalman or extended Kalman) to estimate future interference. Simulation experiments for different topologies are used to verify the significant throughput and energy gains that can be obtained by the proposed power control schemes.

Co-simulation framework for Networked Control Systems over multi-hop mobile ad-hoc networks M Shahidul Hasan

Networked Control Systems over mobile ad-hoc networks have drawn the attention of the researchers because of its suitability in various ad-hoc applications. This paper presents the investigation of such systems using both real wireless communication and co-simulation of MATLAB and OPNET. The plant and the wireless node models are simulated on a computer by MATLAB and OPNET, respectively. The controller runs on a laptop. These two computers communicate using a real wireless link. The interactive co-simulation is applied to a double-pendulum plant with two sensors and two actuators. Both the co-simulation technique and the results are presented and discussed.

Traffic Aware Power Saving Protocol in Multi-hop Mobile Ad-Hoc Networks

This paper presents an optimization of PSM to improve its energy conservation. According to PSM, time is divided into beacon intervals. At the beginning of each beacon interval, all stations must be awake during a specific period called ATIM window to be able to send and receive synchronization messages and announcements of buffered data frames. PSM specifies that a station having sent or received an announcement or having sent a beacon must remain awake during the entire beacon interval. This may lead to wasting energy specially at light traffic loads where stations should conserve the most. We propose an enhancement called the Traffic Aware Power Saving Mode (TA-PSM) to solve this problem by allowing nodes to enter the doze state when they are no more involved in data delivery even if they have already sent a beacon, an ATIM or an ATIM-ACK. Our objective is to reduce the energy consumption without any throttling to throughput. Extensive simulations based on fixed and dynamic topologies showed that TA-PSM provides a much better energy conservation and a lower power consumption per delivered data frame.