Current Search: Mobile communication systems -- Technological innovations (x)
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- Title
- Key management in mobile ad hoc networks.
- Creator
- Wu, Bing., Florida Atlantic University, Wu, Jie, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
In mobile ad hoc networks (MANETs), providing secure communications is a big challenge due to unreliable wireless media, host mobility and lack of infrastructure. Usually, cryptographic techniques are used for secure communications in wired networks. Symmetric and asymmetric cryptography have their advantages and disadvantages. In fact, any cryptographic means is ineffective if its key management is weak. Key management is also a central aspect for security in mobile ad hoc networks. In...
Show moreIn mobile ad hoc networks (MANETs), providing secure communications is a big challenge due to unreliable wireless media, host mobility and lack of infrastructure. Usually, cryptographic techniques are used for secure communications in wired networks. Symmetric and asymmetric cryptography have their advantages and disadvantages. In fact, any cryptographic means is ineffective if its key management is weak. Key management is also a central aspect for security in mobile ad hoc networks. In MANETs, the computational load and complexity for key management are strongly subject to restriction by the node's available resources and the dynamic nature of network topology. We proposed a secure and efficient key management framework (SEKM) for MANETs. SEKM builds a PKI by applying a secret sharing scheme and using an underlying multicast server groups. In SEKM, each server group creates a view of the certificate authority (CA) and provides certificate update service for all nodes, including the servers themselves. Motivated by the distributed key management service, we introduced k-Anycast concept and proposed three k-anycast routing schemes for MANETs. k-anycast is proposed to deliver a packet to any threshold k members of a set of hosts. Our goal is to reduce the routing control messages and network delay to reach any k servers. The first scheme is called controlled flooding. The second scheme, called component-based scheme I, is to form multiple components such that each component has at least k members. The third scheme, called component-based scheme II, in which the membership a component maintains is relaxed to be less than k. Collaborative and group-oriented applications in MANETs is an active research area. Group key management is a central building block in securing group communications in MANETs. However, group key management for large and dynamic groups in MANETs is a difficult problem. We propose a simple and efficient group key management scheme that we named SEGK for MANETs, which is based on n-party Diffie-Hellman (DH). The basic idea of our scheme is that a physical multicast tree is formed in MANETs for efficiency. To achieve fault tolerance, double multicast trees are constructed and maintained. A group coordinator computes and distributes intermediate keying materials to all members through multicast tree links. All group members take turns acting as group coordinator and distributing the workload of group rekeying during any change of group membership. Every group member computes the group key in a distributed manner.
Show less - Date Issued
- 2006
- PURL
- http://purl.flvc.org/fcla/dt/12234
- Subject Headings
- Electronic commerce--Technological innovations, Mobile commerce--Technological innovations, Wireless communication systems--Management, Mobile communication systems--Management
- Format
- Document (PDF)
- Title
- Cross-domain authentication for multi-protocol phones.
- Creator
- Thakker, Chetan., Florida Atlantic University, Pandya, Abhijit S., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
The last decade has seen a surge in demand for cellular and WLAN networks. With the introduction of Voice Over IP, cellular companies are looking at WLAN-Cellular integrated networks that shall provide users with economical voice and data services. These networks shall be complimentary to the existing cellular networks. A lot of money is spent in registering and authenticating new users, since they are separately authenticated and registered on the WLAN and Cellular domains. This leads to...
Show moreThe last decade has seen a surge in demand for cellular and WLAN networks. With the introduction of Voice Over IP, cellular companies are looking at WLAN-Cellular integrated networks that shall provide users with economical voice and data services. These networks shall be complimentary to the existing cellular networks. A lot of money is spent in registering and authenticating new users, since they are separately authenticated and registered on the WLAN and Cellular domains. This leads to extra costs for the company. Thus for the integrated networks to have an impact on the market some issues such as simpler authentication and registration must be resolved. Therefore we propose a new inter-working model that shall addresses the authentication and registration problem for an integrated network for voice and data. The Single authentication system of the new inter-working model, shall authenticate the user in an integrated network using the SIM credentials, this authentication shall be valid for both voice and data. Also registration costs will be saved by preventing separate registration of users in the WLAN and Cellular domain.
Show less - Date Issued
- 2005
- PURL
- http://purl.flvc.org/fcla/dt/13260
- Subject Headings
- Integrated services digital networks, Digital telephone systems, Wireless communication systems--Technological innovations, Mobile communication systems--Technological innovations
- Format
- Document (PDF)
- Title
- A Phased Approach to Evaluate the Performance of Handoff by Mobile Handsets.
- Creator
- Siddiqui, Arjumand Fatima, Pandya, Abhijit S., Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
The ever increasing demand for capacity in wireless cellular networks is resolved by decreasing the size of the cells. The smaller cells created inside large cells are called microcells and they cover smaller and dense areas. As a result of this, the mobile device ends up changing the base stations or performing handover at a much higher rate. To maintain the reliability and quality of the call, it is obligatory to ascertain that the handover is performed at a proper location. If the handover...
Show moreThe ever increasing demand for capacity in wireless cellular networks is resolved by decreasing the size of the cells. The smaller cells created inside large cells are called microcells and they cover smaller and dense areas. As a result of this, the mobile device ends up changing the base stations or performing handover at a much higher rate. To maintain the reliability and quality of the call, it is obligatory to ascertain that the handover is performed at a proper location. If the handover is delayed or the mobile handset drags its base station, it is more probable that either the call will drop or the quality of the call will be compromised. The last thing a mobile handset user would want is to experience any of these two consequences. In this thesis we study the methods to analyze the performance ofhandover by the mobile handsets in the drive setup under test. This thesis presents a model for analyzing the performance ofhandoffbased on the measurements ofthe received signal strength indicator and the color code recorded by the mobile handset in the drive test field path. The model from the simulations is seen to yield results that agree with other research about the performance of mobile handsets.
Show less - Date Issued
- 2007
- PURL
- http://purl.flvc.org/fau/fd/FA00012551
- Subject Headings
- Mobile communication systems--Design, Wireless communication systems--Technological innovations, Cellular telephones--Design
- Format
- Document (PDF)
- Title
- Studies on performance aspects of smart wireless devices and related network services.
- Creator
- Noori, Aziz Ulhaq, Neelakanta, Perambur S., Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
This study is a focused effort on elucidating the performance aspects of modern, handheld wireless devices and associated mobile network services. Specifically addressed thereof are: (i) Assessing the performance details on certain hardware sections of smart handheld devices and (ii) determining the performance profile of market penetration considerations vis-à-vis provisioning mobile networks. To meet the scope of this research, the projected efforts are exercised in compiling relevant...
Show moreThis study is a focused effort on elucidating the performance aspects of modern, handheld wireless devices and associated mobile network services. Specifically addressed thereof are: (i) Assessing the performance details on certain hardware sections of smart handheld devices and (ii) determining the performance profile of market penetration considerations vis-à-vis provisioning mobile networks. To meet the scope of this research, the projected efforts are exercised in compiling relevant literature and deciding the said hardware and technoeconomic performance issues. Hence, written in two parts, Part A is devoted to hardware performance details of smart, handheld devices relevant to (a) delay issues in PCB layouts; (b) crosstalk problems at the baseband level (audio/multimedia) using EMI concepts and (c) ascertaining non-catastrophic EMP/EMI effects at the RF-sections so as to implement protection strategies via compensating networks. Part B is concerned with the technoeconomics of wireless networks in supporting mobile (handheld devices). Correspondingly, two market related considerations versus service performance details are considered. The first one refers to deducing a relative performance index that includes technology (mobile speed) details plus economics profiles of the users in the service area. The second task refers to elucidating a performance index of such services in terms of hedonic pricing heuristics. The theoretical aspects of the test studies as above are supplemented with experimental and/or simulation details as appropriate. Hence, the efficacy of performance details are discussed in real-world applications. Lastly, possible research items for future studies are identified as open-questions.
Show less - Date Issued
- 2015
- PURL
- http://purl.flvc.org/fau/fd/FA00004395, http://purl.flvc.org/fau/fd/FA00004395
- Subject Headings
- Mobile communication systems -- Standards, Network performance (Telecommunications), Smartphones, Technoeconomcs, Wireless communication systems -- Technological innovations
- Format
- Document (PDF)
- Title
- Knowledge Discovery Through Drive Test Data Visualization.
- Creator
- Saxena, Shalini, Pandya, Abhijit S., Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
With the increasing number of cellular phone service subscribers, the telecommunications service providers have placed immense emphasis on improving audio quality and ensure fewer dropped calls. Handoff behavior of all handsets is an important factor in quality of service of a mobile phone service. This thesis focuses on the analysis of large volumes of diagnostic data collected from mobile phones in the real world and the identification of aberrant behavior of a mobile handset under test by...
Show moreWith the increasing number of cellular phone service subscribers, the telecommunications service providers have placed immense emphasis on improving audio quality and ensure fewer dropped calls. Handoff behavior of all handsets is an important factor in quality of service of a mobile phone service. This thesis focuses on the analysis of large volumes of diagnostic data collected from mobile phones in the real world and the identification of aberrant behavior of a mobile handset under test by means of drive test data visualization. Our target was to identify poor mobility decisions that are made by the handsets in calls. Premature, delayed or exceedingly sensitive decisions are considered poor mobility decisions. The goal was to compare a set of behaviors from a baseline unit (one accepted to generally operate well). We were able to identify a particular call that was exhibiting a different path (talking to a different cell than expected or taking longer to move to a new cell). We designed a chi-square statistical test to evaluate the performance of specific mobile handset models. We also developed a mobility tool that evaluated the handset's performance by means of mapping the handoffs on the Google Maps. The mapping of the handoffs by means of the Google Maps were very powerful in identifying the above mentioned mobility patterns.
Show less - Date Issued
- 2007
- PURL
- http://purl.flvc.org/fau/fd/FA00012548
- Subject Headings
- Mobile communication systems--Quality control, Wireless communication systems--Technological innovations, Cellular telephones--Design
- Format
- Document (PDF)
- Title
- Investigation of debonding failures in sandwich constructions.
- Creator
- Sendlein, Lyle Scott., Florida Atlantic University, Merry, Stephanie L., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
Debonding failure of cored marine composite materials is investigated. A new test method that subjects the bond line between the core and the face sheets to a shear stress singularity is presented and studied analytically by laminated beam shear deformation theory, numerically by the finite element method, and experimentally with specimens of glass/polyester face sheets on balsa wood or PVC core sandwich beams.
- Date Issued
- 1989
- PURL
- http://purl.flvc.org/fcla/dt/14519
- Subject Headings
- Mobile communication systems--Design, Wireless communication systems--Technological innovations, Cellular telephones--Design
- Format
- Document (PDF)
- Title
- Smart campus.
- Creator
- Danda, Naga Prakash, Agarwal, Ankur, Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
The Smart Campus project envisions a university campus where technology assists faculty, staff, students and visitors to improve and more efficiently accomplish their daily activities. The objective of this project is to develop a smart phone application that assists users in finding a certain location on campus, locating their friends and professors, interacting with any student or professors of the campus, get the count of users at certain locations and remain updated about all the events...
Show moreThe Smart Campus project envisions a university campus where technology assists faculty, staff, students and visitors to improve and more efficiently accomplish their daily activities. The objective of this project is to develop a smart phone application that assists users in finding a certain location on campus, locating their friends and professors, interacting with any student or professors of the campus, get the count of users at certain locations and remain updated about all the events and campus news. Through this project, an idea of ‘Futuristic Social Network’ in a Campus is modeled and developed on Android platform.
Show less - Date Issued
- 2014
- PURL
- http://purl.flvc.org/fau/fd/FA00004098, http://purl.flvc.org/fau/fd/FA00004098
- Subject Headings
- Mobile communication systems -- Security measures, Technological innovations -- Social aspects, Ubiquitous computing, Universities and colleges -- Design
- Format
- Document (PDF)
- Title
- Implementations Of The DTM, DADCQ And SLAB VANET Broadcast Protocols For The Ns-3 Simulator.
- Creator
- Alwakeel, Ahmed M., Mahgoub, Imad, Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
This work presents the implementations of three adaptive broadcast protocols for vehicular ad hoc networks (VANET) using the Network Simulator 3 (Ns-3). Performing real life tests for VANET protocols is very costly and risky, so simulation becomes a viable alternative technique. Ns-3 is one of the most advanced open source network simulators. Yet Ns-3 lacks implementations of broadcast protocols for VANET. We first implement the Distance to Mean (DTM) protocol, which uses the distance to mean...
Show moreThis work presents the implementations of three adaptive broadcast protocols for vehicular ad hoc networks (VANET) using the Network Simulator 3 (Ns-3). Performing real life tests for VANET protocols is very costly and risky, so simulation becomes a viable alternative technique. Ns-3 is one of the most advanced open source network simulators. Yet Ns-3 lacks implementations of broadcast protocols for VANET. We first implement the Distance to Mean (DTM) protocol, which uses the distance to mean to determine if a node should rebroadcast or not. We then implement the Distribution-Adaptive Distance with Channel Quality (DADCQ) protocol, which uses node distribution, channel quality and distance to determine if a node should favor rebroadcasting. The third protocol, Statistical Location-Assisted Broadcast protocol (SLAB), is an improvement of DADCQ which automates the threshold function design using machine learning. Our NS-3 implementations of the three protocols have been validated against their JiST/SWANS implementations.
Show less - Date Issued
- 2016
- PURL
- http://purl.flvc.org/fau/fd/FA00004565, http://purl.flvc.org/fau/fd/FA00004565
- Subject Headings
- Vehicular ad hoc networks (Computer networks)--Technological innovations., Wireless communication systems--Technological innovations., Mobile communication systems--Technological innovations., Mobile computing., Intelligent transportation systems--Mathematical models., Routing protocols (Computer network protocols)
- Format
- Document (PDF)
- Title
- A Study on Random Sum Statistics: Application to Wireless Network Performance Analysis.
- Creator
- Pattaramalai, Suwat, Aalo, Valentine A., Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
The statistics of random sum is studied and used to evaluate performance metrics in wireless networks. Pertinent wireless network performance measures such as call completion/dropping probabilities and the average number of handovers usually require the probability distributions of the cell dwell time and call holding time; and are therefore not easy to evaluate. The proposed performance evaluation technique requires the moments of the cell dwell time and is given in terms of the Laplace...
Show moreThe statistics of random sum is studied and used to evaluate performance metrics in wireless networks. Pertinent wireless network performance measures such as call completion/dropping probabilities and the average number of handovers usually require the probability distributions of the cell dwell time and call holding time; and are therefore not easy to evaluate. The proposed performance evaluation technique requires the moments of the cell dwell time and is given in terms of the Laplace transform function of the call holding time. Multimedia services that have Weibull and generalized gamma distributed call holding times are investigated. The proposed approximation method uses the compound geometric random sum distribution and requires that the geometric parameter be very small. For applications in which this parameter is not sufficiently small, a result is derived that improves the accuracy (to order of the geometric parameter) of the performance measures evaluated.
Show less - Date Issued
- 2007
- PURL
- http://purl.flvc.org/fau/fd/FA00012575
- Subject Headings
- Mobile communication systems--Technological innovations, Computer network protocols, Local area networks (Computer networks), Differentiable dynamical systems
- Format
- Document (PDF)
- Title
- Adaptive Routing Protocols for VANET.
- Creator
- Skiles, Joanne, Mahgoub, Imad, Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
A Vehicular Ad-hoc Network (VANET) is a wireless ad-hoc network that provides communications among vehicles with on-board units and between vehicles and nearby roadside units. The success of a VANET relies on the ability of a routing protocol to ful ll the throughput and delivery requirements of any applications operating on the network. Currently, most of the proposed VANET routing protocols focus on urban or highway environments. This dissertation addresses the need for an adaptive routing...
Show moreA Vehicular Ad-hoc Network (VANET) is a wireless ad-hoc network that provides communications among vehicles with on-board units and between vehicles and nearby roadside units. The success of a VANET relies on the ability of a routing protocol to ful ll the throughput and delivery requirements of any applications operating on the network. Currently, most of the proposed VANET routing protocols focus on urban or highway environments. This dissertation addresses the need for an adaptive routing protocol in VANETs which is able to tolerate low and high-density network tra c with little throughput and delay variation. This dissertation proposes three Geographic Ad-hoc On-Demand Distance Vector (GEOADV) protocols. These three GEOADV routing protocols are designed to address the lack of exibility and adaptability in current VANET routing protocols. The rst protocol, GEOADV, is a hybrid geographic routing protocol. The second protocol, GEOADV-P, enhances GEOADV by introducing predictive features. The third protocol, GEOADV-PF improves optimal route selection by utilizing fuzzy logic in addition to GEOADV-P's predictive capabilities. To prove that GEOADV and GEOADV-P are adaptive their performance is demonstrated by both urban and highway simulations. When compared to existing routing protocols, GEOADV and GEOADV-P lead to less average delay and a higher average delivery ratio in various scenarios. These advantages allow GEOADV- P to outperform other routing protocols in low-density networks and prove itself to be an adaptive routing protocol in a VANET environment. GEOADV-PF is introduced to improve GEOADV and GEOADV-P performance in sparser networks. The introduction of fuzzy systems can help with the intrinsic demands for exibility and adaptability necessary for VANETs. An investigation into the impact adaptive beaconing has on the GEOADV protocol is conducted. GEOADV enhanced with an adaptive beacon method is compared against GEOADV with three xed beacon rates. Our simulation results show that the adaptive beaconing scheme is able to reduce routing overhead, increase the average delivery ratio, and decrease the average delay.
Show less - Date Issued
- 2017
- PURL
- http://purl.flvc.org/fau/fd/FA00004926, http://purl.flvc.org/fau/fd/FA00004926
- Subject Headings
- Vehicular ad hoc networks (Computer networks)--Design and construction., Routing protocols (Computer network protocols), Wireless sensor networks., Computer algorithms., Mobile computing., Mobile communication systems--Technological innovations., Wireless communication systems--Technological innovations., Intelligent transportation systems--Mathematical models.
- Format
- Document (PDF)
- Title
- Going on the Grid: Secondary Teachers’ Implementation of Mobile Handheld Devices as Instructional Tools.
- Creator
- Berger, Allison S., Weber, Roberta K., Florida Atlantic University, College of Education, Department of Curriculum, Culture, and Educational Inquiry
- Abstract/Description
-
This mixed methods study examined secondary teachers’ technology selfefficacy, their professional development activities regarding mobile handheld devices, and how those activities affect their use of mobile devices as instructional tools. Additionally, this study also explored teachers’ perceptions of other factors that act as barriers or enablers to their use of such devices. The study included 104 middle and high school teachers who taught in a large, urban public school district in the...
Show moreThis mixed methods study examined secondary teachers’ technology selfefficacy, their professional development activities regarding mobile handheld devices, and how those activities affect their use of mobile devices as instructional tools. Additionally, this study also explored teachers’ perceptions of other factors that act as barriers or enablers to their use of such devices. The study included 104 middle and high school teachers who taught in a large, urban public school district in the Southeastern United States. Data were collected through the administration of an electronic survey and semi-structured interviews. The researcher utilized multiple regression and moderator analyses, as well as qualitative analysis of the interview data. The results of the multiple regression analysis revealed teachers’ technologyrelated self-efficacy to be a significant predictor of their instructional use of mobile handheld devices. However, secondary teachers’ level of professional development was found not to contribute significantly to the model. The moderator analysis too revealed professional development to be a nonsignificant factor. The findings of the qualitative phase of the study revealed secondary teachers’ awareness of their varied and fluid technology-related self-efficacy, as well as those factors that modify it. Qualitative data also revealed four categories of essential elements that teachers must have in order to most effectively implement mobile handheld devices within their pedagogy: intellectual capital, emotional capital, social-cultural capital, and technological capital. When lacking, these elements can represent barriers to teachers’ implementation of mobile handheld devices. Targeted professional development and increased funding to minimize the digital divide are recommended to reduce these barriers. The findings of the study inform designers of professional development programs, school and district and secondary teachers, as they are all stakeholders in the process of increasing the effective implementation of mobile handheld devices as instructional tools.
Show less - Date Issued
- 2016
- PURL
- http://purl.flvc.org/fau/fd/FA00004649, http://purl.flvc.org/fau/fd/FA00004649
- Subject Headings
- Computer assisted instruction, Education -- Effect of technological innovations on, Educational innovations, Educational technology, Internet in education, Mobile communication systems in education, Pocket computers
- Format
- Document (PDF)
- Title
- Statistical broadcast protocol design for VANET.
- Creator
- Slavik, Michael J., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
This work presents the development of the Statistical Location-Assisted Broadcast (SLAB) protocol, a multi-hop wireless broadcast protocol designed for vehicular ad-hoc networking (VANET). Vehicular networking is an important emerging application of wireless communications. Data dissemination applications using VANET promote the ability for vehicles to share information with each other and the wide-area network with the goal of improving navigation, fuel consumption, public safety, and...
Show moreThis work presents the development of the Statistical Location-Assisted Broadcast (SLAB) protocol, a multi-hop wireless broadcast protocol designed for vehicular ad-hoc networking (VANET). Vehicular networking is an important emerging application of wireless communications. Data dissemination applications using VANET promote the ability for vehicles to share information with each other and the wide-area network with the goal of improving navigation, fuel consumption, public safety, and entertainment. A critical component of these data dissemination schemes is the multi-hop wireless broadcast protocol. Multi-hop broadcast protocols for these schemes must reliably deliver broadcast packets to vehicles in a geographically bounded region while consuming as little wireless bandwidth as possible. This work contains substantial research results related to development of multi-hop broadcast protocols for VANET, culminating in the design of SLAB. Many preliminary research and development efforts have been required to arrive at SLAB. First, a high-level wireless broadcast simulation tool called WiBDAT is developed. Next, a manual optimization procedure is proposed to create efficient threshold functions for statistical broadcast protocols. This procedure is then employed to design the Distribution-Adaptive Distance with Channel Quality (DADCQ) broadcast protocol, a preliminary cousin of SLAB. DADCQ is highly adaptive to node density, node spatial distribution pattern, and wireless channel quality in realistic VANET scenarios. However, the manual design process used to create DADCQ has a few deficiencies. In response to these problems, an automated design procedure is created that uses a black-box global optimization algorithm to search for efficient threshold functions that are evaluated using WiBDAT. SLAB is finally designed using this procedure., Expansive simulation results are presented comparing the performance of SLAB to two well-published VANET broadcast protocols, p -persistence and Advanced Adaptive Gossip (AAG), and to DADCQ. The four protocols are evaluated under varying node density and speed on five different road topologies with varying wireless channel fading conditions. The results demonstrate that unlike p-persistence and AAG, SLAB performs well across a very broad range of environmental conditions. Compared to its cousin protocol DADCQ, SLAB achieves similar reachability while using around 30% less wireless bandwidth, highlighting the improvement in the automated design methodology over the manual design.
Show less - Date Issued
- 2011
- PURL
- http://purl.flvc.org/FAU/3172947
- Subject Headings
- Vehicular ad-hoc networks (Computer networks), Design and construction, Vehicular ad-hoc networks (Computer networks), Technological innovations, Wireless communication systems, Technological innovations, Wireless communication systems, Security measures, Mobile communication systems, Evaluation
- Format
- Document (PDF)
- Title
- An uncertainty-aware reputation system in mobile networks: analysis and applications.
- Creator
- Li, Feng., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Many emerging mobile networks aim to provide wireless network services without relying on any infrastructure. The main challenge in these networks comes from their self-organized and distributed nature. There is an inherent reliance on collaboration among the participants in order to achieve the aimed functionalities. Therefore, establishing and quantifying trust, which is the driving force for collaboration, is important for applications in mobile networks. This dissertation focuses on...
Show moreMany emerging mobile networks aim to provide wireless network services without relying on any infrastructure. The main challenge in these networks comes from their self-organized and distributed nature. There is an inherent reliance on collaboration among the participants in order to achieve the aimed functionalities. Therefore, establishing and quantifying trust, which is the driving force for collaboration, is important for applications in mobile networks. This dissertation focuses on evaluating and quantifying trust to stimulate collaboration in mobile networks, introducing uncertainty concepts and metrics, as well as providing the various analysis and applications of uncertainty-aware reputation systems. Many existing reputation systems sharply divide the trust value into right or wrong, thus ignoring another core dimension of trust: uncertainty. As uncertainty deeply impacts a node's anticipation of others' behavior and decisions during interaction, we include it in the reputation system. Specifically, we use an uncertainty metric to directly reflect a node's confidence in the sufficiency of its past experience, and study how the collection of trust information may affect uncertainty in nodes' opinions. Higher uncertainty leads to higher transaction cost and reduced acceptance of communication. We exploit mobility to efficiently reduce uncertainty and to speed up trust convergence. We also apply the new reputation system to enhance the analysis of the interactions among mobile nodes, and present three sample uncertainty-aware applications. We integrate the uncertainty-aware reputation model with game theory tools, and enhance the analysis on interactions among mobile nodes., Instead of reactively protecting the mobile networks from existing attacks as in the traditional security paradigms, the analysis in this dissertation gives more insights on nodes' rationality in the interaction, which will enable the mechanism design in mobile networks to be security and incentive compatible. Moreover, we present three sample applications, in which we clearly identify the challenges, specifically formalize the problems, and cleverly employ the uncertainty mitigation schemes. These applications show that the uncertainty definition and mitigation schemes can benefit a broad range of applications, including fields such as security, network services, and routing.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/210520
- Subject Headings
- Wireless communication systems, Security measures, Wireless communication systems, Technological innovations, Computer network architectures, Mobile computing, Ad hoc networks (Computer networks), Security measures
- Format
- Document (PDF)
- Title
- Joint TCP congestion control and wireless-link scheduling for mobile Internet applications.
- Creator
- Li, Zhaoquan., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
The Transmission Control Protocol (TCP) is one of the core protocols of the Internet protocol suite, which is used by major Internet applications such as World Wide Web, email, remote administration and file transfer. TCP implements scalable and distributed end-to-end congestion control algorithms to share network resources among competing users. TCP was originally designed primarily for wired networks, and it has performed remarkably well as the Internet scaled up by six orders of magnitude...
Show moreThe Transmission Control Protocol (TCP) is one of the core protocols of the Internet protocol suite, which is used by major Internet applications such as World Wide Web, email, remote administration and file transfer. TCP implements scalable and distributed end-to-end congestion control algorithms to share network resources among competing users. TCP was originally designed primarily for wired networks, and it has performed remarkably well as the Internet scaled up by six orders of magnitude in the past decade. However, many studies have shown that the unmodified standard TCP performs poorly in networks with large bandwidth-delay products and/or lossy wireless links. In this thesis, we analyze the problems TCP exhibits in the wireless communication environment, and develop joint TCP congestion control and wireless-link scheduling schemes for mobile applications. ... Different from the existing solutions, the proposed schemes can be asynchronously implemented without message passing among network nodes; thus they are readily deployable with current infrastructure. Moreover, global convergence/stability of the proposed schemes to optimal equilibrium is established using the Lyapunov method in the network fluid model. Simulation results are provided to evaluate the proposed schemes in practical networks.
Show less - Date Issued
- 2013
- PURL
- http://purl.flvc.org/fcla/dt/3362481
- Subject Headings
- Wireless communication systems, Quality control, Mobile communication systems, Technological innovations, TCP/IP (Computer network protocol), Ad hoc networks (Computer networks), Computer network protocols, Wireless Internet
- Format
- Document (PDF)
- Title
- Secure routing in wireless sensor networks.
- Creator
- Ibriq, Jamil, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
This research addresses communication security in the highly constrained wireless sensor environment. The goal of the research is twofold: (1) to develop a key management scheme that provides these constrained systems with the basic security requirements and evaluate its effectiveness in terms of scalability, efficiency, resiliency, connectivity, and flexibility, and (2) to implement this scheme on an appropriate routing platform and measure its efficiency., The proposed key management scheme...
Show moreThis research addresses communication security in the highly constrained wireless sensor environment. The goal of the research is twofold: (1) to develop a key management scheme that provides these constrained systems with the basic security requirements and evaluate its effectiveness in terms of scalability, efficiency, resiliency, connectivity, and flexibility, and (2) to implement this scheme on an appropriate routing platform and measure its efficiency., The proposed key management scheme is called Hierarchical Key Establishment Scheme (HIKES). In HIKES, the base station, acting as the central trust authority, empowers randomly selected sensors to act as local trust authorities, authenticating on its behalf the cluster members and issuing to them all secret keys necessary to secure their communications. HIKES uses a novel key escrow scheme that enables any sensor node selected as a cluster head to generate all the cryptographic keys needed to authenticate other sensors within its cluster. This scheme localizes secret key issuance and reduces the communication cost with the base station. The key escrow scheme also provides the HIKES with as large an addressing mechanism as needed. HIKES also provides a one-step broadcast authentication mechanism. HIKES provides entity authentication to every sensor in the network and is robust against most known attacks. We propose a hierarchical routing mechanism called Secure Hierarchical Energy-Efficient Routing protocol (SHEER). SHEER implements HIKES, which provides the communication security from the inception of the network. SHEER uses a probabilistic broadcast mechanism and a three-level hierarchical clustering architecture to improve the network energy performance and increase its lifetime., Simulation results have shown that HIKES provides an energy-efficient and scalable solution to the key management problem. Cost analysis shows that HIKES is computationally efficient and has low storage requirement. Furthermore, high degree of address flexibility can be achieved in HIKES. Therefore, this scheme meets the desired criteria set forth in this work. Simulation studies also show that SHEER is more energy-efficient and has better scalability than the secure version of LEACH using HIKES.
Show less - Date Issued
- 2007
- PURL
- http://purl.flvc.org/FAU/42771
- Subject Headings
- Sensor networks, Security measures, Ad hoc networks (Computer networks), Security measures, Wireless communication systems, Security measures, Wireless communication systems, Technological innovations, Mobile computing
- Format
- Document (PDF)
- Title
- Smart Broadcast Protocol Design For Vehicular Ad hoc Networks.
- Creator
- Limouchi, Elnaz, Mahgoub, Imad, Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Multi-hop broadcast is one of the main approaches to disseminate data in VANET. Therefore, it is important to design a reliable multi-hop broadcast protocol, which satis es both reachability and bandwidth consumption requirements. In a dense network, where vehicles are very close to each other, the number of vehicles needed to rebroadcast the message should be small enough to avoid a broad- cast storm, but large enough to meet the reachability requirement. If the network is sparse, a higher...
Show moreMulti-hop broadcast is one of the main approaches to disseminate data in VANET. Therefore, it is important to design a reliable multi-hop broadcast protocol, which satis es both reachability and bandwidth consumption requirements. In a dense network, where vehicles are very close to each other, the number of vehicles needed to rebroadcast the message should be small enough to avoid a broad- cast storm, but large enough to meet the reachability requirement. If the network is sparse, a higher number of vehicles is needed to retransmit to provide a higher reachability level. So, it is obvious that there is a tradeo between reachability and bandwidth consumption. In this work, considering the above mentioned challenges, we design a number of smart broadcast protocols and evaluate their performance in various network den- sity scenarios. We use fuzzy logic technique to determine the quali cation of vehicles to be forwarders, resulting in reachability enhancement. Then we design a band- width e cient fuzzy logic-assisted broadcast protocol which aggressively suppresses the number of retransmissions. We also propose an intelligent hybrid protocol adapts to local network density. In order to avoid packet collisions and enhance reachability, we design a cross layer statistical broadcast protocol, in which the contention window size is adjusted based on the local density information. We look into the multi-hop broadcast problem with an environment based on game theory. In this scenario, vehicles are players and their strategy is either to volunteer and rebroadcast the received message or defect and wait for others to rebroadcast. We introduce a volunteer dilemma game inspired broadcast scheme to estimate the probability of forwarding for the set of potential forwarding vehicles. In this scheme we also introduce a fuzzy logic-based contention window size adjustment system. Finally, based on the estimated spatial distribution of vehicles, we design a transmission range adaptive scheme with a fuzzy logic-assisted contention window size system, in which a bloom lter method is used to mitigate overhead. Extensive experimental work is obtained using simulation tools to evaluate the performance of the proposed schemes. The results con rm the relative advantages of the proposed protocols for di erent density scenarios.
Show less - Date Issued
- 2017
- PURL
- http://purl.flvc.org/fau/fd/FA00004902, http://purl.flvc.org/fau/fd/FA00004902
- Subject Headings
- Vehicular ad hoc networks (Computer networks)--Design and construction., Mobile communication systems., Wireless communication systems--Technological innovations., Wireless sensor networks., Routing protocols (Computer network protocols), Computer algorithms.
- Format
- Document (PDF)
- Title
- An examination of the implementation of the Intel Essentials project-based learning model on middle and secondary reading and language arts FCAT student achievement and engagement.
- Creator
- Wright, Jeremy R., College of Education, Department of Curriculum, Culture, and Educational Inquiry
- Abstract/Description
-
The purpose of this study was to identify (1) the effectiveness of the Intel Essentials model of project-based learning based on student Florida Comprehensive Assessment test (FCAT) reading scores; (2) the differences in student engagement between students in classes with teachers trained in the Intel Essentials model of project-based learning and teachers not trained in the model as measured by the Beliefs about Classroom Structures Survey; (3) the level of implementation (high, average, or...
Show moreThe purpose of this study was to identify (1) the effectiveness of the Intel Essentials model of project-based learning based on student Florida Comprehensive Assessment test (FCAT) reading scores; (2) the differences in student engagement between students in classes with teachers trained in the Intel Essentials model of project-based learning and teachers not trained in the model as measured by the Beliefs about Classroom Structures Survey; (3) the level of implementation (high, average, or low) of teachers trained in the Intel Essentials model of project-based learning; and (4) any correlation between the level of implementation and the level of student engagement. A total of 32 teachers participated in the study. The teachers were split into 2 groups: the experimental group (N = 16) that participated in the Intel Essentials Training, and the control group (N = 16) that did not participate in the training. The results for this study were mixed. The students of the experimental group teachers (N = 780) had significantly higher (p < .05) FCAT scores than that of the control group students (N = 643). The control group with the exception of Motivating Tasks subscale had significantly higher levels of engagement. The correlation between level of implementation and student engagement produced a moderate negative correlation, meaning that the Intel trained teachers with the highest levels of implementation had the lowest levels of engagement.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/369395
- Subject Headings
- School improvement programs, Project method in teaching, Mobile communication systems in education, Academic achievement, Methodology, Education, Secondary, Computer-assisted instruction, Florida Comprehensive Assessment Test, Education, Effect of technological innovations on
- Format
- Document (PDF)