SimuMANET

Simulation software in MANET research is vital. Such a tool provides a versatile mechanism to understand all the involved aspects of these particular systems, from the radio interface to the last communication layer. In this chapter, the authors present the SimuMANET project, a tool for both simulation and field tests purpose. It allows the deployment of wireless reconfigurable ad-hoc networks and MANETs, assisted by a real-time graphical user interface (GUI) for network traffic monitoring and management of radio electric features of the links established between the active network nodes. Due to a set of functionalities, such as GUI, network topology visualization, traffic and motion pattern configuration, and real-time network status analysis, the simulator introduced here becomes a valid tool for both research and education targets. Two scenarios with different types of motion and traffic are simulated using the SimuMANET tool, and the results are shown and commented to illustrate some capabilities of this software.

Potential Area of Research in MANET

The growth of laptop and 802.11/Wi-Fi wireless networking have made Mobile Ad hoc NETworks (MANETs) a popular research topic since the mid to late 1990s. Many academic papers evaluate protocols and abilities assuming varying degrees of mobility within a bounded space, usually with all nodes within a few hops of each other and usually with nodes sending data at a constant rate. Different protocols are then evaluated based on the packet drop rate, the overhead introduced by the routing protocols, and other measures. Research in MANET is like playing in a vast playground with only few known rules and large number of unknown rules applied to its different areas. Some areas are still unknown and some areas are at its early stage. Some of the research challenges that MANET present are dynamic topologies, battery lifetime, disconnected operations, security, et cetera. In general there are three types of MANET: vehicular ad hoc networks, intelligent vehicular ad hoc network, and Internet based mobile ad hoc networks. Each of these three types has its own research areas.

Modelling WSNs Using OMNeT++

Wireless sensor networks (WSNs) have been used to observe and monitor many environments for specific purposes and in many ways over the past few years. A number of operational trade-offs are possible when planning a WSN, influencing coverage, bandwidth, redundancy, lifetime, expandability, and so on. However, for systems in potentially hazardous locations or those experiencing restricted access, system unreliability tends to be the greatest operational concern. In the process of creating reliable WSNs for hazardous locations, it is highly desirable to ensure both an accurate and a reliable system design prior to deployment, and with as little unnecessary trade-off as possible. Especially as sensing systems become larger and more complex, and potential failure modes increase, this becomes more difficult to achieve. In an attempt to answer the question of reliability assurance, the authors investigate WSNs in the context of accurate and fast modelling of such networks. A comprehensive comparison of three modelling tools (ns-2, OPNET, and OMNeT++) is explored in this chapter, concluding that OMNeT++ is worthy of study as an alternative to the other two more established tools. As an illustration of the use of OMNeT++, two modelling schemes are simulated and compared against the theory to determine both bit-level correctness, but also to demonstrate ease of modelling and analysis.

Energy Conservation Issues and Challenges in MANETs

Energy efficiency is a major issue of concern in wireless ad hoc networks as mobile nodes rely on batteries, which are limited sources of energy, and, in many environments, it is quite a cumbersome task to replace or recharge them. Despite the progress made in battery technology, the lifetime of battery powered devices continues to be a key challenge, requiring additional research on efficient design of platforms, protocols, and systems. Many tangible efforts are made by many researchers to reduce the power consumption at protocol level by designing an energy efficient protocol to prolong the lifetime of the networks. The main focus of this chapter is to present a comprehensive analysis of energy efficient techniques in wireless ad hoc networks, integrating various issues and challenges to provide a big picture in this area. This chapter addresses energy management techniques in wireless ad hoc networks, especially in decentralized ad hoc environments.

Incorporating Security and Energy Efficiency for Multimedia Communications in WANets

The security of multimedia data in Wireless Ad hoc Networks (WANet) is commonly provided by encryption, which consists in transforming a plain text message into an unintelligible ciphertext. Nevertheless, the classical and modern ciphers have all been developed without taking into consideration the intrinsic characteristics of multimedia flows. In this chapter, the author proposes to reduce the computational requirements for the multimedia flow’s encryption when the energy is a limited resource, as it is the case of WANets. Thus, the chapter defines a new profile of Secure Real Time Protocol (SRTP), named EE_SRTP. EE_SRTP provides energy efficiency to SRTP, which provides essentially confidentiality, message authentication, and replay protection to the RTP traffic. In EE_SRTP, the author exploits the dependency existing between the frames created by the inter-frame coding to further improve the energy-efficiency of the encryption process. In contrast with the existing approaches, this chapter presents an experimental model that integrates EE_SRTP to Video LAN Coding (VLC). Therefore, to validate EE_SRTP, the author implements a secure version of VLC (SecVLC). The performance evaluation demonstrates clearly that using this new scheme in the context of wireless ad hoc nodes allows saving energy while ensuring a high level of content confidentiality, without adding an overhead to the wireless network.

Security Issues and Models in Mobile ad hoc Networks

This chapter covers issues related to security in mobile ad hoc networks. It acts as a comprehensive survey material covering the cryptographic schemes and trust modeling techniques traditionally found in mobile ad hoc network (MANET) survey articles. The need for hybrid security techniques, involving both cryptographic approach and trust based model, in a resource constrained ad hoc network, is also emphasized in this work. Additionally, the lack of realism in the research works related to ad hoc network security is also pointed out. The state of the art in ad hoc security should employ hybrid techniques that can be easily implemented in an ad hoc network. This will lead to the large scale deployment of mobile ad hoc networks in various context-aware applications.

Analyzing Performance of Ad hoc Routing Protocols under Various Constraints

The mobility of nodes in mobile ad hoc networks and absence of any centralized control cause unpredictable changes in the network topologies. This makes routing a challenging task. Several routing protocols for mobile ad-hoc networks have come into existence. The protocols are classified in mainly in three categories: proactive, reactive, and hybrid. In this chapter, a study of one of each of the proactive and reactive protocols (respectively, Destination Sequence Distance Vector routing [DSDV], and Dynamic Source Routing [DSR]) is presented. The performance of above said protocols has been measured under varying mobility environment using NS-2 simulator based upon three quality metrics: average end-to-end delay, throughput, and jitter.

Connectivity as a Fundamental Characteristic of Mobile Ad Hoc Networks

In this chapter, the idea of formulating the node connectivity into a form suitable for the purpose of monitoring the dynamic of any given node pair was proposed. It had been able to show that the node connectivity time constitutes the length of time where node-pairs are connected and communication sessions can be established. By analytical calculation and simulation, the node connectivity time depends on the relative velocity of the node-pair. It shows that there is an upper limit and a lower limit for the connection time. Between these limits, communication sessions can be carried out. In order to monitor the quality of connection between a node-pair and for the whole route which is made up of a collection of node-pairs, npem, npcm, and nci are introduced. The nci is shown to be a viable way to estimate the quality of node-pair connection in terms of its timeliness. The index, nci, could be used as one of the metrics to identify and select the best path to the destination.

Environment Design Architecture of MANET

Mobile Ad-hoc Network (MANET) is a new standard of wireless wearable devices enabling instantaneous person-to-person, person-to-machine, or machine-to-person communications immediately and easily. MANET is a compilation of wireless mobile hosts forming a temporary network without the aid of any stand-alone infrastructure or centralized administration or self organization network. MANET has the aspects such as wireless connection, constantly changing topology, scattered operation, and ease of deployment. These capabilities make MANETs very attractive to applications ranging from simple wireless network coverage in offices and warehouses to emergency rescue/response and military operations, law enforcement, and smart environments (including intelligent transport systems). In this chapter, the authors discuss MANET environment and network architecture, which should be kept in mind at design phase of MANET. The authors also discuss: MANET parameters, environment deviations, routing protocol performance considerations, and MANET security challenges.

Topology-based Classification of Multicast Routing Protocols for Mobile Ad hoc Networks

This chapter presents an exhaustive survey on the different categories of topology-based multicast routing protocols that have been proposed for mobile ad hoc networks (MANETs). Due to the inherent broadcast nature of the wireless medium, one-to-many multicast communications are characteristic of most of the MANET applications. MANET multicast routing protocols are primarily classified as tree-based and mesh-based protocols depending on the underlying topology used for communication. Tree-based protocols are further classified to source-tree based and shared-tree based depending on whether the tree is rooted at the multicast source or a common node. Further, there are several sub-categories of source-tree based and shared-tree based multicast routing protocols. The mesh-based multicast protocols are primarily categorized to source-initiated and receiver-initiated protocols depending on which entity (the source node or the receiver nodes) initiates the mesh formation. The book chapter explains in detail the working of eleven different multicast routing protocols, covering all of the sub-categories of tree-based and mesh-based routing protocols.