Network Simulation Tools for Supporting Teaching in Computer Networks

Computer networks have evolved dramatically in recent years and consequently qualified and experienced network administrators are highly sought after, which in turn has led to the development of specialised computer networking courses at many universities. In this chapter, the authors investigate 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 results of their research show that students appreciate the use of network simulators and see them as an effective approach to learning computer networking concepts and gaining the relevant experience. This was also confirmed by the actual performance of students who experienced different levels of exposure to networks simulators during their studies. The authors furthermore investigate the use of interactive, electronically assessed lab sessions, where students get immediate and interactive feedback while they are going through lab exercises. Their research shows that this approach not only releases the lecturer from less demanding students to better support weaker students, but that this will also lead to improved student performance and better student retention.

OPNET Simulation Setup for QoE Based Network Selection

In its most generic sense, the user-centric view in telecommunications considers that the users are free from subscription to any one network operator and can instead dynamically choose the most suitable transport infrastructure from the available network providers for their terminal and application requirements. In this approach, the decision of interface selection is delegated to the mobile terminal enabling end users to exploit the best available characteristics of different network technologies and network providers, with the objective of increased satisfaction. In order to more accurately express the user satisfaction in telecommunications, a more subjective and application-specific measure, namely, the Quality-of-Experience (QoE) is introduced. QoE is the core requirement in future wireless networks and provisions. It is a framework that optimizes the global system of networks and users in terms of efficient resource utilization and meeting user preferences (guaranteeing certain Quality-of-Service [QoS] requirements). A number of solution frameworks to address the mentioned problems using different theoretical approaches are proposed in the research literature. Such scholarly approaches need to be evaluated using simulation platforms (e.g., OPNET, NS2, OMNET++, etc.). This chapter focuses on developing the simulation using a 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, implementing an example scenario, and generating and analyzing the results.

Simulating Game Applications in Mobile IPv6 Protocol

This chapter proposes a novel game-based green interface/network selection mechanism that is an extension to the multi-interface fast-handover mobile IPv6 protocol and works when the mobile node has more than one wireless interface. 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. Additionally, 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.

Future Approach of Next Generation Cellular Mobile Communications

The tremendous use of telecommunication services and the existence of various types of mobile devices and networks impose a huge need for a new technology that can integrate these devices and networks to provide adequate services and applications to satisfy the user’s needs. The new technology tries to eliminate all boundaries of telecommunications and leads to a universal approach that is able to demonstrate an easy and efficient technique to overcome all technical and managerial issues. This chapter, first, studies and analyzes the performance of existing mobile systems and their services and estimates the future aspects of next generation mobile communications. Second, a new approach is proposed and investigated. The new approach is based on using the abilities of satellite communications as part of the mobile communication systems. Such an approach introduces advanced communication solutions that could be set up anywhere/anytime subject to the existence of satellite coverage.

Toward Distributed QoS Driven Wireless Messaging Infrastructure

The 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. Meeting these challenges requires the mobile operators to change the way they design their telephony and messaging systems. As the mobile market moves to become more service centric, rather than technology centric, Quality of Service (QoS) has grown to become imperative, since in the Telecoms innovative services are very often short lived, where the quality aspects of a system and the provided services contribute as key differentiators. Thus, the main focus of this chapter is based around the QoS issues which have led to the consideration of a distributed messaging model to address the challenges faced in the Telecoms industry.

Wireless Identity Management

In the wireless era, digital users in the electronic world (e-world) are represented by sets of data called Digital Identities (ID), which they use, among other functions, for authentication purposes. Within the e-world it is risky to lose an identity and so security solutions are required to protect IDs. Information security should provide the necessary Identity Management (IDM) process to mitigate that threat. Moreover, efficient protection of digital identities would encourage users to enter the digital world without worries. The suggested solution depends on three dimensions: management, security solution, and security dimensions. The proposed model appears as a multi-layered security approach, since 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.

Modeling of TCP Reno with Packet-Loss and Long Delay Cycles

The Transport Control Protocol (TCP) is the dominant transport layer protocol in the Internet Protocol (IP) suite, as it carries a significant amount of the Internet traffic, such as Web browsing, file transfer, e-mail, and remote access. Therefore, huge efforts have been devoted by researchers to develop suitable models that can help with evaluating its performance in various network environments. Some of these models are based on analytical or simulation approaches. This chapter 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. The two models are based on the TCP Reno flavor, as it is one of the most popular implementations on the Internet. These two models were implemented in a user-friendly TCP Performance Evaluation Package (TCP-PEP). The TCP-PEP was used to investigate the effect of packet-loss and long delay cycles on the TCP performance, measured in terms of sending rate, throughput, and utilization factor. The results obtained from the PFTK and PLLDC models were compared with those obtained from equivalent simulations carried-out on the widely used NS-2 network simulator. The PLLDC model provides more accurate results (closer to the NS-2 results) than the PFTK model.

A Location-Based Power Conservation Scheme for MANETs

In a Mobile Ad Hoc Network (MANET), a mobile node consumes its power in message communication, message processing, and other operation missions. The amount of power a mobile node consumes for communication is the highest and the dominant as compared to what a node consumes for other tasks. The power consumed in communication is proportional to the square of the nodes’ radio transmission range (R); therefore, minimizing R contributes to a significant reduction in power consumption and consequently increases node battery-power lifetime. This chapter presents a description and performance evaluation of a new efficient power conservation scheme, namely, the Location-Based Power Conservation (LBPC) scheme. It is based on the concept of reducing R by utilizing locally available nodes’ location information to adjust R according to one of the three proposed radius adjustment criteria: farthest, average, and random. So that instead of transmitting with full power to cover up to its maximum radio transmission range (Rmax), the transmitting node adjusts R to less than Rmax, which provides a power conservation factor equivalent to (R/Rmax)2.

Simulation of a Dynamic-Noise-Dependent Probabilistic Algorithm in MANETs

In the current dynamic probabilistic algorithm, the retransmission probability (pt) has always been formulated as a linear/non-linear function of a single variable, namely, the number of first-hop neighbors (k), and therefore denoted as pt(k). The performance of the probabilistic algorithm has severely suffered in the presence of noise due to the reduction in the probability of reception (pc) of route request packets by receiving nodes. This chapter presents a detailed description of a new dynamic probabilistic algorithm in which pt is determined as a function of k and pc, and therefore, it is referred to as the Dynamic Noise-Dependent Probabilistic (DNDP) algorithm. The DNDP algorithm is implemented using the Mobile Ad Hoc Network (MANET) Simulator (MANSim), which is used to simulate a number of scenarios to evaluate and compare the performance of the algorithm with pure flooding and fixed and dynamic probabilistic algorithms. The simulation’s results demonstrated that the DNDP algorithm provides an excellent performance in various network conditions, where it almost maintains the same network reach-ability in noiseless and noisy environments, with the noisy environments inflicting an insignificant increase in the number of redundant retransmissions.

Modeling and Simulation of IEEE 802.11 Wireless LANs

Stochastic discrete event simulation methodology is becoming increasingly popular among network researchers worldwide in recent years. This popularity results from the availability of various sophisticated and powerful simulation software packages, and also because of the flexibility in model construction and validation offered by simulation. In this chapter, the authors describe their 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). This 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. This chapter also emphasizes that selecting a good simulator is crucial in modeling and performance analysis of wireless networks.