Mobile Ad Hoc Networks Research Research Articles

Clustering, Routing, Scheduling, and Challenges in Bio-Inspired Parameter Tuning of Vehicular Ad Hoc Networks for Environmental Sustainability

Vehicular ad hoc networks (VANETs) are wireless networks of automotive nodes. Among the strategies used in VANETs to increase network connectivity are broadcast scheduling, data aggregation, and vehicular node clustering. In the context of extremely high node mobility and ambiguous vehicle distribution (on the road), VANETs degrade in flexibility and quick topology, facing significant issues such as network physical layout construction and unstable connections. These challenges make it difficult for vehicle communication to be robust, reliable, and scalable, especially in urban traffic networks. Numerous research investigations have revealed a nearly optimal solution to various VANET difficulties through the application of techniques derived from nature and evolution. On the other hand, as key productivity sectors continue to demand more energy, sustainable and efficient ways of using non-renewable resources continue to be developed. With the help of information and communication technologies (ICT), parameter tuning approaches can reduce accident rates, improve mobility, and mitigate environmental impacts. In this article, we explore evolutionary algorithms to mobile ad hoc networks (MANETs), as well as vehicular ad hoc networks (VANETs). A discussion of three major categories of optimization is provided throughout the paper. There are several significant research works presented regarding parameter tuning in cluster formation, routing, and scheduling of broadcasts. Toward the end of the review, key challenges in VANET and MANET research are identified.

CSMCSM

Many MANET research works are based on the popular informal definition that MANET is a wireless ad-hoc network that has neither infrastructure nor backbone and every network node is autonomous and moves depending on its mobility. Unfortunately, this definition pays no attention to the network servers that are essential in core-based, mission-critical, and military MANETs. In core-based MANETs, external intrusion detection systems (IDS) cannot detect internal Byzantine attacks; in addition, internal Byzantine fault tolerant (BFT) systems are unqualified to detect typical external wireless attack. Therefore, there is a real need to combine both internal and external mobile ad-hoc network (MANET) ID systems. Here, CSMCSM is presented as a two-level client server model for comprehensive security in MANETs that integrates internal and external attack detectors in one device. The internal component is based on a BFT consensus algorithm while the external component employs decision tree to classify the MANET attacks.

Cache-Aware Query-Broadcast to Improve QoS of Routing Protocols in MANETs

Recent research in Mobile Ad-hoc Networks mostly deals to minimize the congestion in the network. In this regard, a variety of query-broadcast techniques have been proposed, and employed to reduce routing overhead such as the congestion, route-latency and energy-consumption. Such techniques mainly focus on reducing unnecessary propagation of route-query by repealing the query-broadcast. In our research findings, we found these repealing techniques have extra routing-overhead of chasing the route-query thus increasing energy-consumption and slowing down the route-discovery. In particular, this motivates us to propose a cache-aware broadcasting technique. In order to evaluate the proposed technique, the critical and analytical assessment is done in terms of query-diffusion, route-latency, packet-delivery ratio and energy-consumption ratio.

AUV Link Mobile Ad-Hoc Network Examination

Wireless optical communication systems allow reliable communication in the ultraviolet (UV) range, and protected from intentional suppression and interception, both in the presence and in the absence of direct visibility between the transmitter and the receiver. Currently, the actual and insufficiently explored direction is the development and research of mobile ad-hoc networks (MANET) with a UV communication channel. To analyze the capacity of a mobile network of UV communications with different spatial orientation of network nodes, it is necessary to take into account not only their coordinates and elevation angles but also azimuths. NLOS UV bandwidth models have been developed using three types of modulation: on-off keying (OOK), pulse-phase modulation (PPM), digital pulse interval modulation (DPIM) with a different number of guard intervals. The noted advantages of DPIM, which are most important for the implementation of a mobile self-organizing network with a UV channel, are: it does not require symbolic synchronization of the transmitter and receiver, it requires a smaller frequency band compared to PPM, it has a higher energy efficiency compared to OOK. A parametric approximation of losses in the NLOS UV channel has been performed, taking into account the azimuthal deviations of the transmitter and receiver for specific parameters of the communication system. Has been done a performance simulation of the MANET network with an ultraviolet communication channel Has been calculated values of the bit error rate (BER), and bit rate for a system with different types of modulation with low, medium, and high noise levels in the channel. With the use of parametric approximation of losses in the channel, are analyzed the BER and the bitrate of the UV communication system with an azimuthal deviation within 30 degrees. Based on the obtained simulation results, prospects for the further development of mobile self-organizing networks with a UV channel are indicated to improve their reliability and performance.

Analytical comparisons of query-broadcast repealing schemes in MANETs

Recent research in mobile ad-hoc networks (MANETs) mostly deals to minimize the broadcast expenses of route discovery by controlling the query-broadcast. In this regard, a variety of broadcast-repealing schemes have been proposed, and employed to improve effectiveness and efficiency in various aspects of route-discovery considering time and energy. These schemes mainly focus on reducing unnecessary propagation of route-query by repealing the query-broadcast. Time-to-live based broadcast is the most common controlled-flooding scheme widely used in routing protocols. Recently some other broadcast-repealing schemes are proposed which work based on chasing-policy. The critical and analytical assessment to evaluate these schemes such aspects is of great importance. In this paper, we investigate their query-diffusion process, and their merits and demerits.

A Study on Cluster Stabilization Strategies for Human-Driven MANETs

Clustering is a commonly used method to adequately manage the network resources provided by mobile ad hoc networks (MANETs). In order to work appropriately in these networks, clustering protocols integrate stabilizing strategies that cope with topological changes caused by node motion. Although there is a number of studies related to clustering, cluster stability remains as a critical feature that has been barely addressed. It is not known, for instance, how stability of clustering protocols is affected when network nodes move following human mobility patterns (human-driven MANETs). The aim of this paper is to explore this open issue in order to improve the performance of clustering protocols in a human-driven environment and, in this way, to advance MANET research one step toward the deployment of real networks. To this end, the performance of several stabilizing strategies is assessed considering a network scenario where nodes roam according to the self-similar least-action walk (SLAW) model, which integrates several statistical features of human motion. Additionally, this work proposes to classify the stabilizing strategies into clusterhead-election based strategies, strategies based on relaxed-validity policies and strategies controlling the number of clusters. Our findings show that clustering protocols have to integrate flexible policies in order to improve stability as well as strategies dealing with burst reaffiliations and big-sized clusters.

Securing Mobile Ad Hoc Networks

The flexibility and openness of mobile ad hoc networks (MANETs) make them attractive for various types of applications such as military communication, emergency search and rescue operations, disaster recovery, battlefields, communication between moving vehicles (VANET etc. However, MANETs are highly susceptible to various security threats due to their inherent characteristics that can adversely affect their performance. In order to provide secure communication in mobile ad hoc networks, it is required to understand various possible attacks at different layers of the communication protocol stack. The intent of this paper is to provide structured and comprehensive study of prominent security attacks reported in the literature for mobile ad hoc networks. In addition, we also discuss various well-known reactive and proactive security solutions proposed in literature to prevent those attacks in MANETs. Finally, the paper is concluded with a brief discussion on future direction of research in MANETs.

Research on Gibbs Mobility Model for Ad Hoc Networks in the Contingency-Responding Battle

Mobile Ad Hoc Network (MANET) because of its flexible, networking fast, strong anti-destroying ability and other characteristics, is widely used in military, disaster relief, interim meetings and other scenes[1]. Simulation is the primary means of mobile Ad Hoc network research and evaluation of performance, while mobility model is an important component of the performance simulation of Ad Hoc networks. The authenticity of device nodes’ movement in the manner, directly affects the network to evaluate the effectiveness and reliability of the simulation. This paper selects Gibbs group mobility model, and simulate the characteristics of the nodes’ mobility in contingency-responding scene.

Secluding Efficient Geographic Multicast Protocol against Multicast Attacks

A Mobile Ad-hoc Network (MANETs) is composed of Mobile Nodes without any infrastructure. The network nodes in MANETs, not only act as ordinary network nodes but also as the routers for other peer devices. The dynamic topology, lack of a fixed infrastructure and the wireless nature make MANETs susceptible to the security attacks. To add to that, due to the inherent, severe constraints in power, storage and computational resources in the MANET nodes, incorporating sound defense mechanisms against such attacks is also non-trivial. Therefore, interest in research of Mobile Ad-hoc NETworks has been growing since last few years. Security is a big issue in MANETs as they are infrastructure-less and autonomous. The main objective of this paper is to address some basic security concerns in EGMP protocol which is a multicast protocol found to be more vulnerable towards attacks like blackhole, wormhole and flooding attacks. The proposed technique uses the concepts of certificate to prevent these attacks and to find the malicious node. These attacks are simulated using NS2.28 version and the proposed proactive technique is implemented. The following metrics like packet delivery ratio, control overhead, total overhead and End to End delay are used to prove that the proposed solution is secure and robust.

Mapping the Intellectual Structure of Mobile Ad Hoc Networks

To explore the intellectual structure of mobile ad hoc networks (MANET) research in the last decade, this study identified the most important publications and the most influential scholars as well as the correlations among these scholar’s publications. In this study, bibliometric, social network analysis techniques are used to investigate the intellectual pillars of the MANET literature. By analyzing 41,001 citations of 1,941 articles published in SCI and SSCI journal in MANET area between 2001 and 2010, this study maps a knowledge network of MANET studies. The results of the mapping can help identify the research direction of MANET research and provide a valuable tool for researchers to access the literature in this area.

Link availability prediction-based reliable routing for mobile ad hoc networks

Mobile ad hoc networks (MANETs) are becoming increasingly important. The most challenging issue in conjunction with MANETs is reliable routing, that is, the procedure that determines the trajectory of packets travelling over the network. The authors present a novel link availability-based routing protocol (LBRP) for MANETs. Compared with other routing protocols, LBRP takes unpredictable topology change and frequent link failure into account. Meanwhile, by a rough estimation of the distance between two adjacent nodes, the proposed approach is able to accurately predict link availability over a short period of time. Simulation results are given to verify the approach. This study could serve as groundwork for further MANET research, including analysing and optimising other network protocols. Reliable routing protocol can effectively improve the availability and reliability of upper layer services and quality of service.

Simulation of Packet Telephony in Mobile Adhoc Networks Using Network Simulator

Packet Telephony has been regarded as an alternative to existing circuit switched fixed telephony. To propagate new idea regarding Packet Telephony researchers need to test their ideas in real or simulated environment. Most of the research in mobile ad-hoc networks is based on simulation. Among all available simulation tools, Network Simulator (ns2) has been most widely used for simulation of mobile ad-hoc networks. Network Simulator does not directly support Packet Telephony. The authors are proposing a technique to simulate packet telephony over mobile ad-hoc network using network simulator, ns2.

Recent developments and experimental guidelines in mobile ad-hoc networks

The Mobile Ad-hoc Network (MANET) is one of the most vibrant and active current research topics. This work investigates and analyses recent research trends and presents experimental guidelines on MANETs. More than 1900 MANET-related papers were collected and surveyed in IEEE/IEE Electronic Library (IEL Online) from 1998 to 2004. The research trends, qualitative analysis and simulation guidelines from 15 major MANET issues are investigated to assist the user in conducting MANET research. On the basis of recent seven-year trends, we found that some issues, such as routing, power management and bandwidth management, have attracted much attention. We also found that some issues have potential study values, such as radio interface and security. In the qualitative analysis, we found that some factors such as scalability, stability and reliability attracted much attention in major MANET issues. The essential simulation metrics for various MANET issues are identified and listed for experimental guidelines. The analysis results also demonstrate the utilisation trends for various MANET simulators.

Ad Hoc Mobile Wireless Networks Routing Protocols – A Review

Mobile ad hoc networks(MANET) represent complex distributed systems that comprise wireless mobile nodes that can freely and dynamically self organize into arbitrary and temporary ad-hoc network topologies, allowing people and devices to seamlessly internet work in areas with no preexisting communication infrastructure e.g., disaster recovery environments. An ad-hoc network is not a new one, having been around in various forms for over 20 years. Traditionally, tactical networks have been the only communication networking application that followed the ad-hoc paradigm. Recently the introduction of new technologies such as Bluetooth, IEEE 802.11 and hyperlan are helping enable eventual commercial MANET deployments outside the military domain. These recent revolutions have been generating a renewed and growing interest in the research and development of MANET. To facilitate communication within the network a routing protocol is used to discover routes between nodes. The goal of the routing protocol is to have an efficient route establishment between a pair of nodes, so that messages can be delivered in a timely manner. Bandwidth and power constraints are the important factors to be considered in current wireless network because multi-hop ad-hoc wireless relies on each node in the network to act as a router and packet forwarder. This dependency places bandwidth, power computation demands on mobile host to be taken into account while choosing the protocol. Routing protocols used in wired network cannot be used for mobile ad-hoc networks because of node mobility. The ad-hoc routing protocols are divided into two classes: table driven and demand based. This paper reviews and discusses routing protocol belonging to each category.

Multihop Ad Hoc Networking: The Theory

This article reviews the basic principles behind mobile ad hoc networks (MANET) and critically discusses approximately ten years of research in this field. We summarize the main achievements and point out the limits of MANET research. This research was conducted under the assumption that the networks mainly will be used for large-scale general consumer applications, and nodes would be ubiquitous, thus reasonably dense and active. Both assumptions do not reflect reality and certainly would not be true in an initial phase of deployment. A lack of realism regarding the objective of MANET coupled with a lack of realism during the design of MANET are the main causes of MANET running a high risk of failure

A Cluster-Based QoS Multipath Routing Protocol for Large-Scale MANET

To support QoS routing in MANET (mobile ad hoc networks) is a core issue in the research of MANET. Numerous studies have shown the difficulty for provision of quality-of-service (QoS) guarantee in Mobile Ad hoc networks. This paper proposes a scheme referred to a cluster-based QoS multipath routing protocol (CQMRP) that provides QoS-sensitive routes in a scalable and flexible way in mobile Ad Hoc networks. In the strategy, each local node just only maintains local routing information of other clusters instead of any global ad hoc network states information. It supports multiple QoS constraints. The performance of the protocol is evaluated by using the OPNET simulator and the result shows that this protocol can provide an available approach to QoS multipath routing for mobile Ad Hoc networks.

From battlefields to urban grids: New research challenges in ad hoc wireless networks

There has been much talk over the past two decades about commercialization of the mobile ad hoc network (MANET) technology. Potential ad hoc network applications with some commercial appeal are now finally emerging, “drafted” by the enormously successful wireless LAN technology. Closely coupled to commercial applications and critically dependent on commercial ad hoc networks will be the “pervasive computing” applications. Since military and civilian emergency MANETs have been around for over three decades, and since the Government has continuously supported MANET research for as many years, it may seem natural to assume that all the research has already been done and that commercial MANETs can be deployed by simply leveraging the military and civilian research results. Unfortunately, there is a catch. Commercial MANETs (and therefore pervasive computing applications) will evolve in a way totally different from their military counterparts. Most importantly, they will start small, and will initially be tethered to the Internet. They will be extremely cost-aware. They will also need to cater to a variety of different applications. This is in sharp contrast with the large scale, autonomous, special purpose and cost insensitive military networks. In this paper we review a typical “battlefield” MANET application and contrast it to two emerging commercial MANET scenarios—the urban vehicle grid and the Campus network. We compare characteristics and design goals and make the case for new research to help kick off commercial MANETs. In particular we argue that P2P technology will be critical in the early evolution of commercial MANETs and identify research directions for P2P MANETs.

Mobile ad hoc networking: imperatives and challenges

Mobile ad hoc networks (MANETs) represent complex distributed systems that comprise wireless mobile nodes that can freely and dynamically self-organize into arbitrary and temporary, “ad-hoc” network topologies, allowing people and devices to seamlessly internetwork in areas with no pre-existing communication infrastructure, e.g., disaster recovery environments. Ad hoc networking concept is not a new one, having been around in various forms for over 20 years. Traditionally, tactical networks have been the only communication networking application that followed the ad hoc paradigm. Recently, the introduction of new technologies such as the Bluetooth, IEEE 802.11 and Hyperlan are helping enable eventual commercial MANET deployments outside the military domain. These recent evolutions have been generating a renewed and growing interest in the research and development of MANET. This paper attempts to provide a comprehensive overview of this dynamic field. It first explains the important role that mobile ad hoc networks play in the evolution of future wireless technologies. Then, it reviews the latest research activities in these areas, including a summary of MANET’s characteristics, capabilities, applications, and design constraints. The paper concludes by presenting a set of challenges and problems requiring further research in the future.

Dynamic task-based anycasting in mobile ad hoc networks

Mobile ad hoc networks (MANETs) have received significant attention in the recent past owing to the proliferation in the numbers of tetherless portable devices, and rapid growth in popularity of wireless networking. Most of the MANET research community has remained focused on developing lower layer mechanisms such as channel access and routing for making MANETs operational. However, little focus has been applied on higher layer issues, such as application modeling in dynamic MANET environments. In this paper, we present a novel distributed application framework based on task graphs that enables a large class of resource discovery based applications on MANETs. A distributed application is represented as a complex task comprised of smaller sub-tasks that need to be performed on different classes of computing devices with specialized roles. Execution of a particular task on a MANET involves several logical patterns of data flow between classes of such specialized devices. These data flow patterns induce dependencies between the different classes of devices that need to cooperate to execute the application. Such dependencies yield a task graph (TG) representation of the application.We focus on the problem of executing distributed tasks on a MANET by means of dynamic selection of specific devices that are needed to complete the tasks. In this paper, we present simple and efficient algorithms for dynamic discovery and selection (instantiation) of suitable devices in a MANET from among a number of them providing the same functionality. This is carried out with respect to the proposed task graph representation of the application, and we call this process Dynamic Task-Based Anycasting. Our algorithm periodically monitors the logical associations between the selected devices, and in the event of a disruption in the application owing to failures in any component in the network, it adapts to the situation and dynamically rediscovers the affected parts of the task graph, if possible. We propose metrics for evaluating the performance of these algorithms and report simulation results for a variety of application scenarios differing in complexity, traffic, and device mobility patterns. From our simulation studies, we observed that our protocol was able to instantiate and re-instantiate TG nodes quickly and yielded high effective throughput at low to medium degrees of mobility and not much below 70% effective throughput for high mobility scenarios.