In the information technology age and with tremendous advancement in computer and communication technologies, a computer network has become an integral part of our daily life in universities, organizations, schools, factories, and almost everywhere. Furthermore, there has been a remarkable increase in computer networks users, services, and applications. Therefore huge efforts have put forward by researchers, designers, managers, analysts, and professionals to accomplish an optimum cost-effective performance to satisfy users, services, and applications needs.
Computer networks designers use performance evaluation as an integral component of the design effort. The designer relies on the simulation model to provide guidance in choosing among alternative design choices, to detect bottlenecks in network performance, or to support cost-effective analyses. Another important use of simulation is as a tool to help validate an analytical approach to performance evaluation. Computer simulation is widely-used in investigating the performance of existing and proposed computer networks designs, protocols, security algorithms, models, etc.
The application of computer simulation can potentially improve the quality and effectiveness of the network design. It is generally unfeasible to implement a computer network design, protocol, algorithm, or model before valid tests are performed to evaluate their performance. It is clear that testing and evaluating such implementations with real hardware is quite hard, in terms of the manpower, time, cost, and other resources.
The preferred alternative is to model these implementations in a detailed simulator and consequently perform various scenarios to measure their performance for various patterns of realistic computer networks environments (e.g., connection media, node densities, node mobility, transmission range, size of traffic, etc.). The main challenge to simulation is to model the process as close as possible to reality; otherwise it could produce entirely different performance characteristics from the ones discovered during actual use. In addition, the simulation study must be repeatable, unbiased, realistic, statistically sound, and cost-effective. There are a number of computer network simulators that have been developed throughout the years to support computer networks design and modeling. Some of them are of general-purpose use and other dedicated to simulate particular types of computer networks. Simulation in Computer Network Design and Modeling: Use and Analysis
is composed of 24 chapters written by highly qualified scholars discussing a wide range of topics; these are: modeling and simulation of game theory in wireless networks routing and mobile IPv6 protocol, evaluation and simulation of Vertical Handoff Algorithms (VHAs), simulation of various network protocols and applications using a variety of network simulators (e.g., OPNET, NS-2, OMNeT++, MANSim), Simulation in amateur packet radio networks, modeling of TCP in wireless network, network security, distributed systems, cellular networks, simulations models, and network simulation as a teaching aid.
Chapter 1, “Modeling and Simulation of Game Applications in Ad Hoc Wireless Networks Routing,” presents a game theory based routing algorithm, which defines the best route based on the power consumption that each intermediate node will suffer to forward a packet, the price the destination will pay to the source and the amount of compensation the source will pay to each intermediate node. The chapter also presents a polynomial time algorithm that can give a Nash Equilibrium path and use it to evaluate the performance of the game.
Chapter 2, “Simulating Game Applications in Mobile IPv6 Protocol,” proposes a novel game-based green interface/network selection mechanism, which is an extension to the multi-interface fast-handover mobile IPv6 protocol. The mechanism controls the handover decision process by deciding whether a handover is needed or not and helps the node to choose the right access point at the right time. What’s more, the mechanism switches the mobile nodes interfaces “ON” and “OFF” when needed to control the mobile node’s energy consumption and improves the handover latency.
Chapter 3, “Evaluation Model for Vertical Handoff Algorithms,” describes a novel evaluation model for Vertical Handoff Algorithms (VHAs). The design of the new evaluation model is based on the multi-criteria evaluation methodology and criticality analysis, which permitted the model to be developed as a software component. The new proposed evaluation model is flexible in terms of the number of evaluation parameters and facilitates the analysis of VHAs by researchers.
Chapter 4, “Simulation of Vertical Handoff Algorithms for Heterogeneous Wireless Network,” discusses the importance of computer simulation is in studying and analyzing communication networks; especially, simulation of Vertical Handoff Algorithms (VHAs) for heterogeneous wireless networks. The chapter also presents and compares using two approaches for VHAs simulations, namely, using network simulator and using a general purpose programming languages by means of two study cases. The first case considers the use of network simulator NCTUns (National Chiao Tung University Network Simulator), while the second case considers the use of MATLAB.
Chapter 5, “Modeling and Simulation of IEEE 802.11 Wireless LANs: A Case Study of a Network Simulator,” describes the authors experience in using the Network Simulator 2 (NS-2), a discrete event simulation package, as an aid to modeling and simulation of the IEEE 802.11 Wireless Local Area Networks (WLANs). The chapter provides an overview of NS-2 focusing on simulation environment, architecture, model development and parameter setting, model validation, output data collection and processing, and simulation execution. The strengths and weaknesses of NS-2 are discussed. The chapter also emphasizes that selecting a good simulator is crucial in modeling and performance analysis of wireless networks.
Chapter 6, “OPNET Simulation Setup for Quality of Experience (QoE) Based Network Selection,” focuses on developing a simulation setup for QoE based network selection using standard discrete event network simulator, OPNET. It outlines the general development procedures of different components in simulation and details the following important aspects: Long Term Evolution (LTE) network component development, impairment entity development, implementing IPv6 flow management, developing an integrated heterogeneous scenario with LTE and WLAN, implement an example scenario, and generating and analyzing the results.
Chapter 7, “Simulation of Multihop Wireless Networks in OMNeT++,” presents a brief description of the OMNeT++ network simulator with main emphasis on the InetManet framework, and how this framework is especially oriented to simulate Mobile Ad Hoc Networks (MANETs) and Wireless Mesh Networks (WMNs).
Chapter 8, “Simulation of a Dynamic-Noise-Dependent Probabilistic Algorithm in MANETs,” provides a detail description and performance evaluation of the novel Dynamic Noise-Dependent Probabilistic (DNDP) algorithm for route discovery in noisy Mobile Ad Hoc Networks (MANETs). The performance of the DNDP algorithm is evaluate and compared with pure flooding, fixed and dynamic probabilistic algorithms.
Chapter 9, “A Location-Based Power Conservation Scheme for MANETs: A Step towards Green Communications,” addresses the issue of energy efficiency in Mobile Ad Hoc Networks (MANETs), where a node consumes most of its power in message communication. In particular, this chapter presents a description and performance evaluation of the new efficient power conservation scheme for message communication, namely, the Location-Based Power Conservation (LBPC) scheme. The simulation results demonstrated that the scheme can provide power conservation ratios between 10 to 50% without adding any extra overheads or complexity to the routing algorithm.
Chapter 10, “Comparing Various Route Discovery Algorithms in Ad hoc Wireless Networks,” compares the performance of various route discovery algorithms in ad hoc wireless networks. The chapter starts with an introduction to the use of simulation in ad hoc wireless networks, and then addresses the process of evaluating route discovery algorithms in such networks. It also provides a description of network simulator used in this chapter, namely, MANSim. It discusses its capabilities, features, and main programming modules. The chapter presents the tutorial steps required to set-up and run a simulation for the pure flooding mechanism. Using the same approach (simulation setup and run), the tutorial progressively approaches the issues of pure flooding mechanism by rallying over the different flooding optimization algorithms: Probabilistic, Location-Aided Routing Scheme 1 (LAR-1), LAR-1-Probabilsitic (LAR-1P), and Optimal Multipoint Relaying (OMPR). The results obtained through the different simulations are analyzed and compared. Based on these results conclusions are drawn, and a number of suggestions and recommendations for future work are pointed-out. This chapter will help practitioners of various kinds (academics, professionals, researchers, and students) grasp a solid understanding for the behavior of ad hoc wireless networks route discovery algorithms and develop an appreciation for flooding optimization mechanisms. It also substantiates the case of experimenting via simulation with such models and shows how the different simulation parameters interplay.
Chapter 11, “Simulation in Amateur ‘Packet Radio’ Networks,” summarizes the results of recent experiments in network simulations by using amateur radio software in a local area network. The author tested main features of those amateur radio programs and their repercussions to the functionality of simulated networks and to the comfort and satisfaction in average network participants. Described tests help practitioners, students and teachers in computer science and communication technologies, in implementing amateur radio within the existing computer networks and in planning and using telecommunication systems – without making any investment in hardware infrastructure.
Chapter 12, “Modeling of TCP Reno with Packet-Loss and Long Delay Cycles,” presents a description, derivation, implementation, and comparison of two well-known analytical models, namely, the PFTK and PLLDC models. The first one is a relatively simple model for predicting the performance of the TCP protocol, while the second model is a comprehensive and realistic analytical model. In order to validate the accuracy of the PFTK and PLLDC models, the results obtained from these two models are compared with those obtained from equivalent simulations carried-out on the widely used NS-2 network simulator.
Chapter 13, “Wireless Identity Management: Multimodal Biometrics and Multilayered IDM,” proposes a multi-layered security model for authentication purposes within the e-world. It depends on three dimensions: management, security solution and security dimensions; and it tries to integrate different security technologies and multimodal biometrics tools and practices, such as wireless management, policies, procedures, guidelines, standards and legislation. The advantages, limitations and requirements of the proposed model are discussed.
Chapter 14, “A Framework Model for Using NS-2 for Mobile Ad hoc Networks Security Management,” provides a detail description of a framework for designing, analyzing, deployment and enforcement of high level security management for Mobile Ad Hoc Networks (MANETs). The framework, which can be used by researchers, academics, security administrators, network designers and post-graduate students, is designed and simulated using the object oriented Network Simulator-2 (NS-2). The chapter also provides a full illustration of how to design and implement a secure MANET and maintaining the security essentials using NS-2. Finally, this chapter provides a description of the future trend NS-3, which is the “eventual replacement” of NS-2.
Chapter 15, “Investigating the Performance of the TSS Scheme in Noisy MANETs,” describes the implementation and investigates the performance of the threshold secret sharing (TSS) node authentication scheme in noisy MANETs. A number of simulations are performed using the MANET Simulator (MANSim) to estimate the authentication success ratio for various threshold secret shares, number of nodes, node speeds, and noise-levels. The outcomes of these simulations are so important to facilitate efficient network management.
Chapter 16, “A Hybrid Port-Knocking Technique for Host Authentication,” presents a detail description, implementation, and performance evaluation of a new Port-Knocking (PK) technique, namely the Hybrid PK (HPK) technique, which is developed to avert all types of port attacks and meets all network security requirements. It is referred to as the HPK technique because it combines four well-known security concepts: PK, cryptography, steganography, and mutual authentication. The performance of the HPK technique is evaluated and compared with other PK techniques through simulation.
Chapter 17, “State-of-the-Art and Future Prospective of Network Security,” considers and addresses several aspects of network security, in an effort to provide a publication that summarizes the main current status and the promising and interesting future directions and challenges. In particular, the chapter presents the state-of-the-art in Internet security, secure services, security in mobile systems and trust, and anonymity and privacy.
Chapter 18, “Toward Distributed QoS Driven Wireless Messaging Infrastructure,” discusses the Telecoms market and shows that Telecoms market is demanding more services which involve an increased mobile accessibility to the Internet, real time video transmission, real time games, Voice Over IP (VOIP) and business critical transactions such as billing transactions and banking services. As the mobile market moves to become more service centric, rather than technology centric, Quality of Service (QoS) has grown to become imperative. Thus, the main focus of this chapter is based around the QoS issues which have lead to the consideration to a distributed messaging model to address the challenges faced in the Telecoms industry.
Chapter 19, “A Simulation Model for Large Scale Distributed Systems,” presents the design characteristics of the simulation model proposed in MONARC 2, which is a multithreaded, process oriented simulation framework designed for modeling large scale distributed systems, allows the realistic simulation of a wide-range of distributed system technologies, with respect to their specific components and characteristics. The model includes the necessary components to describe various actual distributed system technologies, and provides the mechanisms to describe concurrent network traffic, evaluate different strategies in data replication, and analyze job scheduling procedures. The chapter also provides a background on the use of discrete-event simulators in the design and development of large scale distributed systems due to their efficiency, scalability, and most importantly their core abstractions of process and event map neatly to the components and interactions of modern-day distributed systems allowing designing realistic simulation scenarios. The chapter analyses existing work, outlining the key decision points taken in the design of the MONARC’s simulation model.
Chapter 20, “Future Approach of Next Generation Cellular Mobile Communications,” studies and analyzes the performance of existing mobile systems and services, and estimates the future aspects of next generation mobile communications. It also proposes and investigates the performance of a new approach that is based on using the abilities of satellite communications as part of the mobile communication systems. Such an approach introduced advanced communication solutions that could be set up anywhere/anytime subject to the existence of satellite coverage. The proposed solution tries to eliminate all boundaries of telecommunications and leads to a universal approach to overcome all technical and managerial issues.
Chapter 21, “Evaluation of Simulation Models,” reviews and evaluate the performance of simulation models that are concentrating on develop types of discrete event simulation. Different models are discussed but special attention is given to systems that use spatial decomposition. This involves that data may have to be transmitted by mediator tiles to its purpose depending on the decomposition post. For congruent simulation the challenge is to decompose the tool in order to make effective use of the original processor design. This chapter also discusses a number of methodologies and architectural design that have been developed for efficient simulation model decomposition.
Chapter 22, “Analyzing and Evaluating Current Computer Networks Simulation Models,” presents the methodologies and techniques used to evaluate and analyze the performance of communication and computer networks routers, such as mathematical analysis, computer simulations techniques, and empirical measurements; identify the workload required for accomplishing a simulation model or mathematical analysis; identify the main metrics used to evaluate, manage and control the performance of the computer networks; present the advantage and disadvantage of these techniques; identify the challenges facing these different methodologies.
Chapter 23, “Network Simulation Tools for Supporting Teaching in Computer Networks,” investigates the use of network simulation tools as an alternative to be employed in computer networking laboratories. Network simulation tools provide students with the opportunity to freely experiment with virtual computer networks and equipment without the expensive costs associated with real networking hardware. The outcome of the this research shows that this approach not only releases the lecturer from less demanding students to better support weaker students, but will also lead to improved student performance and better student retention.
Chapter 24, “Wire and Wireless Local Area Networks Simulation: OPNET Tutorial,” presents a number of tutorials for using OPNET to setup different wire and wireless LANs simulations. These tutorials help network designers, analysts, managers, researchers, etc to simulate, evaluate, and investigate the performance of more complicated and realistic networks. Moreover, it encourages and helps students to easily perform LANs simulations for better understand to the network performance under different network conditions.
The book concludes with compilation of references, contributors’ biographies, and a comprehensive index.