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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Performance analysis of IEEE 802.11A signals under different operational environments /

Chan, Hsiung Wei Roy. January 2004 (has links) (PDF)
Thesis (M.S. in Electrical Engineering)--Naval Postgraduate School, Sept. 2004. / Thesis advisor(s): Tri T. Ha, Randy L. Borchardt. Includes bibliographical references (p. 89). Also available online.
12

Wireless local network architecture for Naval medical treatment facilities /

Deason, Russell C. January 2004 (has links) (PDF)
Thesis (M.S. in Information Technology Management)--Naval Postgraduate School, Sept. 2004. / Thesis advisor(s): Alex Bordetsky. Includes bibliographical references (p. 89-93, 95-99). Also available online.
13

A Markov chain approach to IEEE 802.11 WLAN performance analysis

Xiong, Lixiang. January 2008 (has links)
Thesis (Ph. D.)--University of Sydney, 2008. / Includes tables. Includes list of publications. Title from title screen (viewed October 30, 2008). Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy to the School of Electrical and Information Engineering, Faculty of Engineering and Information Technologies. Includes bibliographical references. Also available in print form.
14

Design of a Fast Location-Based Handoff Scheme for Vehicular Networks

Wang, Yikun January 2013 (has links)
IEEE 802.11 is an economical and efficient standard that has been applied to vehicular networks. However, the long handoff latency of the standard handoff scheme for IEEE 802.11 has become an important issue for seamless roaming in vehicular environments, as more handoffs may be triggered due to the higher mobility of vehicles. This thesis presents a new and fast location-based handoff scheme particularly designed for vehicular environments. With the position and movement direction of a vehicle and the locations of the surrounding APs, our protocol is able to accurately predict several possible APs that the vehicle may visit in the future and to assign these APs different priority levels. APs on higher priority levels will be first scanned. Once a response to scanning from an AP is received, the scanning process ends immediately. A blacklist scheme is also used to exclude those APs that showed no response to the scanning during previous handoffs. Thus, time spent on scanning APs is supposed to be significantly reduced. The simulation results show that the proposed scheme attains not only a lower prediction error rate, but also a lower MAC layer handoff latency, and that it has a smaller influence on jitter and throughput; moreover, these results show that the proposed scheme has a smaller total number of handoffs than other handoff schemes.
15

Honeypot pro rodinu bezdrátových komunikačních protokolů IEEE 802.11 / Honeypot for wireless communication protocols of IEEE 802.11 family

Řezáč, Michal January 2020 (has links)
Objective of this master thesis solves possible way of WiFi Honeypot realisation, which is constructed to detecet malicious network activity and attacks in radio environment that uses a set of IEEE 802.11 protocols. A specific configuration was created on the mITX format motherboard and contains scripts and software for data collection, analysis and its evaluation. Based on information and knowledge about specific network attacks it is possible to identify data traffic leading to anomalies and detect possible network attack. The final device was tested in real use for long-term data collection and evaluation of network activity in the given location. This fulfills the main goal of this work, which is implementation of WiFi Honeypot with support for IEEE 802.11 protocols and with possible deployment for real use.
16

Exposing the medium access control vulnerabilities in IEEE 802.11.

January 2007 (has links)
Ma Yu Tak. / Thesis submitted in: October 2006. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (leaves 70-73). / Abstracts in English and Chinese. / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- IEEE 802.11 Standard --- p.4 / Chapter 3 --- Vulnerabilities of IEEE 802.11 --- p.8 / Chapter 3.1 --- Authentication Vulnerabilities --- p.8 / Chapter 3.2 --- Medium Access Control Vulnerabilities --- p.9 / Chapter 3.3 --- Proposed Counter-Measures --- p.10 / Chapter 4 --- Denial-of-Service Attacks by Exploiting the MAC protocol --- p.12 / Chapter 5 --- Simulation Results --- p.20 / Chapter 5.1 --- General DoS Attack Simulations --- p.21 / Chapter 5.1.1 --- Topology 1: A Simple Wireless Network --- p.21 / Chapter 5.1.2 --- Topology 2: Wireless Network in Ad-Hoc Mode --- p.24 / Chapter 5.1.3 --- Topology 3: Network with Hidden Node Problem --- p.29 / Chapter 5.2 --- Targeted DoS Attack Simulations --- p.32 / Chapter 5.2.1 --- Topology 4: A Simple Wireless Network --- p.32 / Chapter 5.2.2 --- Topology 4: A Simple Network with Reversed TCP Flows --- p.38 / Chapter 6 --- Detecting and Solving the Attacks --- p.41 / Chapter 6.1 --- Detection of Attacker --- p.41 / Chapter 6.1.1 --- Detecting General DoS Attackers --- p.41 / Chapter 6.1.2 --- Detecting Targeted DoS Attackers --- p.44 / Chapter 6.2 --- Possible Solutions to the DoS Attacks --- p.53 / Bibliography --- p.70 / Chapter A --- TCP Exponential Backoff with Non-Zero Throughput --- p.74 / Chapter A.1 --- TCP Exponential Backoff Background --- p.74 / Chapter A.2 --- Illustration by Simulation --- p.76 / Chapter A.3 --- Implication of the Finding --- p.77 / Chapter B --- Idle Sense in networks with Hidden Node Problem --- p.79 / Chapter B.1 --- Simulation findings --- p.79 / Chapter B.1.1 --- Four hidden nodes case --- p.79 / Chapter B.1.2 --- Analysis of the simulation results --- p.81 / Chapter B.1.3 --- Study of mixed node types --- p.82 / Chapter B.2 --- Possible approaches to use Idle Sense with Hidden Node Problem --- p.84 / Chapter B.2.1 --- Performance Evaluation --- p.88 / Chapter B.3 --- Conclusions --- p.91
17

A Credit-based Home Access Point (CHAP) to Improve Application Quality on IEEE 802.11 Networks

Lee, Choong-Soo 23 June 2010 (has links)
"Increasing availability of high-speed Internet and wireless access points has allowed home users to connect not only their computers but various other devices to the Internet. Every device running different applications requires unique Quality of Service (QoS). It has been shown that delay- sensitive applications, such as VoIP, remote login and online game sessions, suffer increased latency in the presence of throughput-sensitive applications such as FTP and P2P. Currently, there is no mechanism at the wireless AP to mitigate these effects except explicitly classifying the traffic based on port numbers or host IP addresses. We propose CHAP, a credit-based queue management technique, to eliminate the explicit configuration process and dynamically adjust the priority of all the flows from different devices to match their QoS requirements and wireless conditions to improve application quality in home networks. An analytical model is used to analyze the interaction between flows and credits and resulting queueing delays for packets. CHAP is evaluated using Network Simulator (NS2) under a wide range of conditions against First-In-First- Out (FIFO) and Strict Priority Queue (SPQ) scheduling algorithms. CHAP improves the quality of an online game, a VoIP session, a video streaming session, and a Web browsing activity by 20%, 3%, 93%, and 51%, respectively, compared to FIFO in the presence of an FTP download. CHAP provides these improvements similar to SPQ without an explicit classification of flows and a pre- configured scheduling policy. A Linux implementation of CHAP is used to evaluate its performance in a real residential network against FIFO. CHAP reduces the web response time by up to 85% compared to FIFO in the presence of a bulk file download. Our contributions include an analytic model for the credit-based queue management, simulation, and implementation of CHAP, which provides QoS with minimal configuration at the AP."
18

Wireless LAN security.

January 2005 (has links)
Chan Pak To Patrick. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 82-86). / Abstracts in English and Chinese. / Abstract --- p.i / Acknowledgement --- p.iii / Contents --- p.iv / List of Figures --- p.vii / List of Tables --- p.viii / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Motivation --- p.1 / Chapter 1.2 --- The Problems --- p.3 / Chapter 1.3 --- My Contribution --- p.4 / Chapter 1.4 --- Thesis Organization --- p.5 / Chapter 2 --- Wireless LAN Security Model --- p.6 / Chapter 2.1 --- Preliminary Definitions on WLAN --- p.6 / Chapter 2.2 --- Security Model --- p.7 / Chapter 2.2.1 --- Security Attributes --- p.7 / Chapter 2.2.2 --- Security Threats in WLAN --- p.8 / Chapter 2.2.3 --- Attacks on Authentication Scheme --- p.10 / Chapter 2.2.4 --- Attacks on Keys --- p.10 / Chapter 2.3 --- Desired Properties of WLAN Authentication --- p.11 / Chapter 2.3.1 --- Security Requirements of WLAN Authentication --- p.11 / Chapter 2.3.2 --- Security Requirements of Session Keys --- p.12 / Chapter 2.3.3 --- Other Desired Properties of WLAN Authentication --- p.12 / Chapter 3 --- Cryptography --- p.14 / Chapter 3.1 --- Overview on Cryptography --- p.14 / Chapter 3.2 --- Symmetric-key Encryption --- p.15 / Chapter 3.2.1 --- Data Encryption Standard (DES) --- p.15 / Chapter 3.2.2 --- Advanced Encryption Standard (AES) --- p.15 / Chapter 3.2.3 --- RC4 --- p.16 / Chapter 3.3 --- Public-key Cryptography --- p.16 / Chapter 3.3.1 --- RSA Problem and Related Encryption Schemes --- p.17 / Chapter 3.3.2 --- Discrete Logarithm Problem and Related Encryption Schemes --- p.18 / Chapter 3.3.3 --- Elliptic Curve Cryptosystems --- p.19 / Chapter 3.3.4 --- Digital Signature --- p.19 / Chapter 3.4 --- Public Key Infrastructure --- p.20 / Chapter 3.5 --- Hash Functions and Message Authentication Code --- p.21 / Chapter 3.5.1 --- SHA-256 --- p.22 / Chapter 3.5.2 --- Message Authentication Code --- p.22 / Chapter 3.6 --- Entity Authentication --- p.23 / Chapter 3.6.1 --- ISO/IEC 9798-4 Three-pass Mutual --- p.23 / Chapter 3.6.2 --- ISO/IEC 9798-4 One-pass Unilateral --- p.24 / Chapter 3.7 --- Key Establishment --- p.24 / Chapter 3.7.1 --- Diffie-Hellman Key Exchange --- p.24 / Chapter 3.7.2 --- Station-to-Station Protocol --- p.25 / Chapter 3.8 --- Identity-Based Cryptography --- p.25 / Chapter 3.8.1 --- The Boneh-Franklin Encryption Scheme --- p.26 / Chapter 3.8.2 --- Au and Wei's Identification Scheme and Signature Scheme --- p.27 / Chapter 4 --- Basics of WLAN Security and WEP --- p.29 / Chapter 4.1 --- Basics of WLAN Security --- p.29 / Chapter 4.1.1 --- "Overview on ""Old"" WLAN Security" --- p.29 / Chapter 4.1.2 --- Some Basic Security Measures --- p.29 / Chapter 4.1.3 --- Virtual Private Network (VPN) --- p.30 / Chapter 4.2 --- WEP --- p.31 / Chapter 4.2.1 --- Overview on Wired Equivalent Privacy (WEP) --- p.31 / Chapter 4.2.2 --- Security Analysis on WEP --- p.33 / Chapter 5 --- IEEE 802.11i --- p.38 / Chapter 5.1 --- Overview on IEEE 802.11i and RSN --- p.38 / Chapter 5.2 --- IEEE 802.1X Access Control in IEEE 802.11i --- p.39 / Chapter 5.2.1 --- Participants --- p.39 / Chapter 5.2.2 --- Port-based Access Control --- p.40 / Chapter 5.2.3 --- EAP and EAPOL --- p.40 / Chapter 5.2.4 --- RADIUS --- p.41 / Chapter 5.2.5 --- Authentication Message Exchange --- p.41 / Chapter 5.2.6 --- Security Analysis --- p.41 / Chapter 5.3 --- RSN Key Management --- p.43 / Chapter 5.3.1 --- RSN Pairwise Key Hierarchy --- p.43 / Chapter 5.3.2 --- RSN Group Key Hierarchy --- p.43 / Chapter 5.3.3 --- Four-way Handshake and Group Key Handshake --- p.44 / Chapter 5.4 --- RSN Encryption and Data Integrity --- p.45 / Chapter 5.4.1 --- TKIP --- p.45 / Chapter 5.4.2 --- CCMP --- p.46 / Chapter 5.5 --- Upper Layer Authentication Protocols --- p.47 / Chapter 5.5.1 --- Overview on the Upper Layer Authentication --- p.47 / Chapter 5.5.2 --- EAP-TLS --- p.48 / Chapter 5.5.3 --- Other Popular ULA Protocols --- p.50 / Chapter 6 --- Proposed IEEE 802.11i Authentication Scheme --- p.52 / Chapter 6.1 --- Proposed Protocol --- p.52 / Chapter 6.1.1 --- Overview --- p.52 / Chapter 6.1.2 --- The AUTHENTICATE Protocol --- p.56 / Chapter 6.1.3 --- The RECONNECT Protocol --- p.59 / Chapter 6.1.4 --- Packet Format --- p.61 / Chapter 6.1.5 --- Ciphersuites Negotiation --- p.64 / Chapter 6.1.6 --- Delegation --- p.64 / Chapter 6.1.7 --- Identity Privacy --- p.68 / Chapter 6.2 --- Security Considerations --- p.68 / Chapter 6.2.1 --- Security of the AUTHENTICATE protocol --- p.68 / Chapter 6.2.2 --- Security of the RECONNECT protocol --- p.69 / Chapter 6.2.3 --- Security of Key Derivation --- p.70 / Chapter 6.2.4 --- EAP Security Claims and EAP Methods Requirements --- p.72 / Chapter 6.3 --- Efficiency Analysis --- p.76 / Chapter 6.3.1 --- Overview --- p.76 / Chapter 6.3.2 --- Bandwidth Performance --- p.76 / Chapter 6.3.3 --- Computation Speed --- p.76 / Chapter 7 --- Conclusion --- p.79 / Chapter 7.1 --- Summary --- p.79 / Chapter 7.2 --- Future Work --- p.80 / Bibliography --- p.82
19

Call admission control for adaptive bit-rate VoIP over 802.11 WLAN.

January 2009 (has links)
Cui, Yuanyuan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (p. 64-68). / Abstract also in Chinese. / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1 .1 --- Motivations and Contributions --- p.1 / Chapter 1.2 --- Related Works --- p.3 / Chapter 1.3 --- Organization of the Thesis --- p.4 / Chapter Chapter 2 --- Background --- p.5 / Chapter 2.1 --- IEEE 802.11 --- p.5 / Chapter 2.1.1 --- IEEE 802.11 Topologies --- p.5 / Chapter 2.1.2 --- IEEE 802.11 MAC --- p.8 / Chapter 2.2 --- Voice over Internet Protocol (VoIP) --- p.11 / Chapter 2.2.1 --- A VoIP system --- p.11 / Chapter 2.2.2 --- QoS requirements for VoIP --- p.11 / Chapter 2.2.3 --- VoIP speech codecs --- p.12 / Chapter 2.3 --- VoIP over WLAN --- p.13 / Chapter 2.3.1 --- System Architecture of VoIP over WLAN --- p.14 / Chapter 2.3.2 --- VoIP Capacity over WLAN --- p.15 / Chapter 2.4 --- Skype --- p.16 / Chapter Chapter 3 --- Skype Rate Adaptation Mechanism --- p.17 / Chapter 3.1 --- Experimental Setting --- p.17 / Chapter 3.2 --- Overview --- p.19 / Chapter 3.3 --- Flow Rate Region --- p.20 / Chapter 3.4 --- Feedback: Receiver Report (RR) --- p.21 / Chapter 3.5 --- Bandwidth Usage Target (BM) --- p.24 / Chapter 3.6 --- Summary of Skype Rate Adaptation Mechanism --- p.28 / Chapter 3.7 --- Skype-emulating Traffic Generator --- p.28 / Chapter Chapter 4 --- "Call Admission, Fairness and Stability Control" --- p.32 / Chapter 4.1 --- Unfair and Instability problems for AVoIP --- p.32 / Chapter 4.1.1 --- Analysis --- p.32 / Chapter 4.1.2 --- Simulation Evaluation --- p.34 / Chapter 4.2 --- CFSC scheme --- p.37 / Chapter 4.2.1 --- Pre-admission Bandwidth-reallocation Call Admission Control (PBCAC) --- p.39 / Chapter 4.2.2 --- Fairness Control --- p.42 / Chapter 4.2.3 --- Stability Control --- p.43 / Chapter Chapter 5 --- Performance Evaluation of CFSC --- p.44 / Chapter 5.1 --- Evaluation of Fairness Control --- p.44 / Chapter 5.2 --- Evaluation of Stability Control --- p.46 / Chapter 5.3 --- Evaluation of PBCAC --- p.46 / Chapter 5.4 --- Evaluation of complete CFSC --- p.49 / Chapter Chapter 6 --- Conclusion --- p.51 / Appendices --- p.53 / References --- p.64
20

Design of a Cross-Layer Handover Scheme for Data Transmission

Hsia, Ming-chun 14 September 2007 (has links)
IEEE 802.11-based wireless local area networks (WLANs) have been set up in many public places in last few years. It provides convenient network connectivity to mobile nodes (MNs) and allows users moving from one wireless network to another. With mobility protocol support, such as Mobile IPv6 (MIPv6), people can roam across wireless IP subnets without loss of network-layer connectivity. However, the handover latency may make users feel uncomfortable in MIPv6. To support seamless handover, an enhanced MIPv6 scheme, Fast Handovers for Mobile IPv6 (FMIPv6)[13], was been proposed. In order to further reduce the handover latency, integrating the lower layer procedure with the upper layer procedure is necessary. Unfortunately, when integrating the IEEE 802.11-based standard with FMIPv6, FMIPv6 always fails to perform predictive handover procedure. This may make the handover procedure result in reactive handover. It is because of the protocol nature of IEEE 802.11 and the weak relation between IEEE 802.11 and FMIPv6. Furthermore, a MN can¡¦t receive packets destined to it when it sends the Fast Binding Update (FBU) to the original access router (OAR). This would cause unnecessary packet loss and make the redictive handover have more packet loss then reactive. Those issues will cause quality of services degradation and make real-time applications unreachable. In this dissertation, a low-latency MIPv6 handover scheme will be proposed. It is a FMIPv6-based scheme which is assisted by an active-scan link layer scheme. It has the advantage of FMIPv6 and can reduce unnecessary packet loss when the handover occurs. Also, with the assistance of the active scheme, it can avoid the longest phase that IEEE 802.11 will enter, and can lower the handover latency.

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