1.1 Introduction
Wireless networks using radio frequency technologies to convey data among network points. Since wireless using radio signals, it has a high possibility to be detected and attacked because it is open medium. This is the basic contrast amongst wired and wireless networks, which makes a wireless network substantially more defenseless than a wired. A “Denial of service” or as known as DoS attacks turn into an inexorably predominant security danger. Thus, DoS, as it is regularly shortened, is a malignant attack on a network. This kind of attacks is basically intended to push a network to the brink of collapse by flooding it with futile traffic.

One of the crucial explanations behind the quick development of DDoS attacks is the absence of accessibility of successful solutions for distinguishing and to recognize the attacker, particularly in case of more current and more intelligent DDoS attacks. Moreover, an attacker does not require profound specialized information as the attacker can be attempted with easy to understand attacking tools, for example, Trinoo, TFN, TFN2K, Shft and so on. Furthermore, attack packets show up as a genuine request which is really originating from a staggering number of zombies and spoofed personalities, making it difficult to recognize and piece them.

DoS attack can be divided into 5 types which are network level, operating system level, application level, attacks based on protocols and data flooding. First, attacks at network level achieved by exploiting a bug, poor condition in the software or by trying to remove the hardware resources of the network. Secondly, operating system level will exploit the way the protocol execution of the operating system. The example is Ping of Death or as known as Ping Flood. This attack produces the countless number of ICMP packets that exceeding the limit size of 65535 bytes. The victims get the ping in fragments and begin reassembling the packet. Once the packet is reassembled, it is as well enormous for the buffer and floods it, bringing about reboots or on the other hand, the system hanging.

Application level is a bug that running on the target host is exploited at the application level to expend the resources of target victim. By exploiting a bug, this attack enables a thief to disrupt services by causing inordinate preparing on the target host. One such case of this is the finger bomb assault which diverts the finger order to remote sites. Next, attacks based on protocol features will exploit the standard protocol features. For instance, IP spoofing is utilized to gain unauthorized access to PCs by mirroring a trusted host of IP address. Another attack is Synchronization (SYN) flooding which exploits an imperfection in such a way that hosts actualize the TCP three-way handshake. Lastly, DoS attack on data flooding that attempts to overstrain the bandwidth or host by producing immense volumes of traffic.

This paper is to analyze the performance of QoS on DoS attacks in the wireless network by using Riverbed simulator. Also, this paper will survey of attacks and impact of QoS performance in the network. The simulation results present the impact of network performance of DoS attack in the wireless network.

1.2 Problem Statement
DoS attack is an attack that purposely denying the intended user from using a network source such as an Internet service. DoS attack paralyzes computers or network systems by coordinating flooding traffic originated from multiple hosts simultaneous. The effect of this attack can either make a server crashed or slowing them down. Thus, it makes a system and service inaccessible for the user to use. The basic types of DoS attacks are including consumption of bandwidth or processor time, alteration or pulverization of configuration data and physical destruction of network segments.

Past researchers examine about wireless LAN working, some of them like Gaurav Kumar et al. (2018), analyzing the effect of DoS attacks on the wireless network based on delay, traffic dropped, point to point queuing delay, point to point utilization and point to point throughput. This shows that amount of traffic dropped when DoS attacked.
According to Philip Asuquo et al. (2015), the authors made an analysis on DoS attacks in Delay Tolerant Networks and examined that the effects of DoS attacks in a post-disaster situation based on message delivery. The authors demonstrate that impacts of expanding the number of malicious nodes in the network. There was a critical drop in the message delivery ratio as the number of attackers expanded, there was a lessening in the number of messages effectively transferred to the expected crisis responders.

Suresh Bandaru (2014), examines that there are many kinds of security threats that WLANs can experience the effects. One of the greatest dangers is jamming attacks in DoS. The authors explore frequency sweep jammer and how it diminishes fundamentally the throughput of the system. Channel switching techniques are recommended to be utilized to stay away from degradation of the throughput.
1.3 Project Question
The purpose of this project is to determine the performance of QoS parameters on DoS attack over the wireless network. The following research question for this project is divided into three questions:
PQ Project Question
PQ1 How can DoS attack reliably and efficiently be detected before the attack is observed?
PQ2 How does DoS attack impact the QoS performance in the wireless environment?

PQ3 What is the availability of bandwidth for DoS attacks?
The questions are very important in order to help the successfulness and effectiveness of the project. At the end of this project, the user will know either each of the questions had been successfully done or not. This is also one of the ways of achieving the objectives of this project.

1.4 Project Objective
The objective of this project included:
To identify the DoS attack based on QoS by referring the issues from the research article.

To analyze the QoS performance in wireless Ethernet network over DoS attack.

To evaluate the performance in wireless Ethernet network based on selected QoS parameters.

1.5 Project Scope
The main tasks for this project are to analyze network performance of DoS attacks based on QoS in wireless by using NS3 network simulator software to observe the network behavior on Windows Operating System. Using c language to implement in the simulator. The project focused on determine wireless network QoS performance with and without DoS attacks and make a comparison between it.
1.6 Expected Output
This project is to study, understand, analyze and make a simulation of network performance in wireless environment. This task will produce the details that will give the results of an analysis in QoS performance for DoS attacks based on the comparison of network performance with and without DoS attacks.

1.7 Project Significance
In implementing the project, there will need commitment and sacrifice of time and energy. On the project, from doing research of analyzing QoS performance there needs work hard in achieving the objective. So there are many benefits that can be archived from implementing this project and can know how to analyze the network design and performance of the network area.

1.8 Thesis Organization
This report is organized as following which is consists of six chapter namely Chapter 1: Introduction, Chapter 2: Literature Review, Chapter 3: Project Methodology, Chapter 4: Analysis and Design, Chapter 5: Implementation, Chapter 6: Testing and Validation and Chapter 7: Project Conclusion.

Chapter I: Introduction
This chapter provides an initial overview of the DoS attack and the performance of QoS based on the wireless network. Besides, this chapter will focus on the introduction, project background, also defining the project problem statement, project questions, project objectives, project scope, project contributions and the thesis organization.
Chapter II: Literature Review
This chapter will thrive more in the explanation and details of this project, supported by the reading materials and also the conference paper. Thus, it will present a detailed study of DDoS attacks and existing major defense proposals. This chapter will explore the challenges in defending against DDoS attacks and categorize the existing proposals, highlighting the limitations of each defense mechanism. Also, will illustrate the attack taxonomy and present significant attack defense responses

Chapter III: Project Methodology
This chapter provides the methodology of the analysis process that will be used as part of this project. The project methodology will ease the task of analyzing and organizing the project
Chapter IV: Analysis and Design

This chapter discusses the analysis of the problem and requirement needed in the IoT botnets. Next, this section briefly covers the high-level design, user interface design and the system architecture.
Chapter V: Implementation

This section will cover all the activity involved in the implementation phase, the software development environment setup, software configuration management and the implementation status.

Chapter VI: Testing and Validation

This chapter will be listed briefly and discusses the activity involved in the testing phase, the test plan includes test environment, test schedule and test strategy and also the test result analysis.

Chapter VII: Project Conclusion
The last chapter summarizes the overall project summarization, project contribution, and project limitation. This section will also provide a suggestion for future use.

1.9 Summary
In summary, in order to detect and fight against DoS attacks, it needs to study and analyze how a DoS attack works. This project is to investigate a simulation in the wireless network to analyze the behavior of DoS attack. The overall goal of this paper is to analyze and explore whether wireless networks are flexible to intentional DoS attacks. Moreover, this project will analyses and simulation experiments, the harm that DoS attacks can exact on the performance of a wireless network.