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- Title
- XYZ: A scalable, partially centralized lookup service for large-scale peer-to-peer systems.
- Creator
- Zhang, Jianying., Florida Atlantic University, Wu, Jie, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Peer-to-Peer (P2P) systems are characterized by direct access between peer computers, rather than through a centralized server. File sharing is the dominant P2P application on the Internet, allowing users to easily contribute, search and obtain content. The objective of this thesis was to design XYZ, a partially centralized, scalable and self-organizing lookup service for wide area P2P systems. The XYZ system is based on distributed hash table (DHT). A unique ID and a color assigned to each...
Show morePeer-to-Peer (P2P) systems are characterized by direct access between peer computers, rather than through a centralized server. File sharing is the dominant P2P application on the Internet, allowing users to easily contribute, search and obtain content. The objective of this thesis was to design XYZ, a partially centralized, scalable and self-organizing lookup service for wide area P2P systems. The XYZ system is based on distributed hash table (DHT). A unique ID and a color assigned to each node and each file. The author uses clustering method to create the system backbone by connecting the cluster heads together and uses color clustering method to create color overlays. Any lookup for a file with a color will only be forwarded in the color overlay with the same color so that the searching space is minimized. Simulations and analysis are also provided in this thesis.
Show less - Date Issued
- 2005
- PURL
- http://purl.flvc.org/fcla/dt/13263
- Subject Headings
- Wireless communication systems, Peer-to-peer architecture (Computer networks), Computational grids (Computer systems)
- Format
- Document (PDF)
- Title
- Web-based wireless sensor network monitoring using smartphones.
- Creator
- Marcus, Anthony M., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
This thesis consists of the development of a web based wireless sensor network (WSN) monitoring system using smartphones. Typical WSNs consist of networks of wireless sensor nodes dispersed over predetermined areas to acquire, process, and transmit data from these locations. Often it is the case that the WSNs are located in areas too hazardous or inaccessible to humans. We focused on the need for access to this sensed data remotely and present our reference architecture to solve this problem....
Show moreThis thesis consists of the development of a web based wireless sensor network (WSN) monitoring system using smartphones. Typical WSNs consist of networks of wireless sensor nodes dispersed over predetermined areas to acquire, process, and transmit data from these locations. Often it is the case that the WSNs are located in areas too hazardous or inaccessible to humans. We focused on the need for access to this sensed data remotely and present our reference architecture to solve this problem. We developed this architecture for web-based wireless sensor network monitoring and have implemented a prototype that uses Crossbow Mica sensors and Android smartphones for bridging the wireless sensor network with the web services for data storage and retrieval. Our application has the ability to retrieve sensed data directly from a wireless senor network composed of Mica sensors and from a smartphones onboard sensors. The data is displayed on the phone's screen, and then, via Internet connection, they are forwarded to a remote database for manipulation and storage. The attributes sensed and stored by our application are temperature, light, acceleration, GPS position, and geographical direction. Authorized personnel are able to retrieve and observe this data both textually and graphically from any browser with Internet connectivity or through a native Android application. Web-based wireless sensor network architectures using smartphones provides a scalable and expandable solution with applicability in many areas, such as healthcare, environmental monitoring, infrastructure health monitoring, border security, and others.
Show less - Date Issued
- 2011
- PURL
- http://purl.flvc.org/FAU/3171682
- Subject Headings
- Smartphones, Wireless communication systems, Security measures, Wireless communication systems, Technological innovations, Computer networks, Security measures, Ad hoc networks (Computer networks), Security measures
- Format
- Document (PDF)
- Title
- Very high frequency MIMO underwater acoustic communications in ports and shallow waters.
- Creator
- Real, Gaultier., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
This thesis presents the development of a Multiple-Input Multiple-Output (MIMO) capable high bit rate acoustic modem operating at high frequencies. A MIMO channel estimation technique based on Least-Squares (LS) estimation is developed here. Channel deconvolution is completed using a Minimum Mean-Square Error (MMSE) Linear Equalizer (LE). An Interference Cancellation Linear Equalizer (ICLE) is used to provide the theoretical limit of the MIMO deconvolution process. The RMSE of the channel...
Show moreThis thesis presents the development of a Multiple-Input Multiple-Output (MIMO) capable high bit rate acoustic modem operating at high frequencies. A MIMO channel estimation technique based on Least-Squares (LS) estimation is developed here. Channel deconvolution is completed using a Minimum Mean-Square Error (MMSE) Linear Equalizer (LE). An Interference Cancellation Linear Equalizer (ICLE) is used to provide the theoretical limit of the MIMO deconvolution process. The RMSE of the channel estimation process was 1.83 % and 6.1810 %, respectively for simulated and experimental data. Using experimental data, the RMSE before MIMO deconvolution process was 141.3 % and dropped down to 60.224 % and to 4.4545 %, respectively after LE and ICLE. At raw reception, the RMSE was 101.83 % and dropped down to 9.36 % and to 1.86 % using respectively LE and ICLE with simulated data.
Show less - Date Issued
- 2011
- PURL
- http://purl.flvc.org/FAU/3333309
- Subject Headings
- MIMO systems, Wireless communication systems, Underwater acoustics, Fluid dynamics
- Format
- Document (PDF)
- Title
- A utility-based routing scheme in multi-hop wireless networks.
- Creator
- Lu, Mingming., College of Engineering and Computer Science, Florida Atlantic University, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Multi-hop wireless networks are infrastructure-less networks consisting of mobile or stationary wireless devices, which include multi-hop wireless mesh networks and multi-hop wireless sensor networks. These networks are characterized by limited bandwidth and energy resources, unreliable communication, and a lack of central control. These characteristics lead to the research challenges of multi-hop wireless networks. Building up routing schemes with good balance among the routing QoS (such as...
Show moreMulti-hop wireless networks are infrastructure-less networks consisting of mobile or stationary wireless devices, which include multi-hop wireless mesh networks and multi-hop wireless sensor networks. These networks are characterized by limited bandwidth and energy resources, unreliable communication, and a lack of central control. These characteristics lead to the research challenges of multi-hop wireless networks. Building up routing schemes with good balance among the routing QoS (such as reliability, cost, and delay) is a paramount concern to achieve high performance wireless networks. These QoS metrics are internally correlated. Most existing works did not fully utilize this correlation. We design a metric to balance the trade-off between reliability and cost, and build up a framework of utility-based routing model in multi-hop wireless networks. This dissertation focuses on the variations with applications of utility-based routing models, designing new concepts, and developing new algorithms for them. A review of existing routing algorithms and the basic utility-based routing model for multi-hop wireless networks has been provided at the beginning. An efficient algorithm, called MaxUtility, has been proposed for the basic utility-based routing model. MaxUtility is an optimal algorithm that can find the best routing path with the maximum expected utility., Various utility-based routing models are extended to further enhance the routing reliability while reducing the routing overhead. Besides computing the optimal path for a given benefit value and a given source-destination pair, the utility-based routing can be further extended to compute all optimal paths for all possible benefit values and/or all source-destination pairs. Our utility-based routing can also adapt to different applications and various environments. In the self-organized environment, where network users are selfish, we design a truthful routing, where selfish users have to tell the truth in order to maximize their utilities. We apply our utility-based routing scheme to the data-gathering wireless sensor networks, where a routing scheme is required to transmit data sensed by multiple sensor nodes to a common sink node.
Show less - Date Issued
- 2008
- PURL
- http://purl.flvc.org/FAU/77647
- Subject Headings
- Wireless communication systems, Security measures, Computer network protocols, Computer algorithms, Computer networks, Security measures
- Format
- Document (PDF)
- Title
- Underwater acoustic channel estimation using multiple sources and receivers in shallow waters at very-high frequencies.
- Creator
- Kaddouri, Samar, Beaujean, Pierre-Philippe, Florida Atlantic University, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
The underwater channel poses numerous challenges for acoustic communication. Acoustic waves suffer long propagation delay, multipath, fading, and potentially high spatial and temporal variability. In addition, there is no typical underwater acoustic channel; every body of water exhibits quantifiably different properties. Underwater acoustic modems are traditionally operated at low frequencies. However, the use of broadband, high frequency communication is a good alternative because of the...
Show moreThe underwater channel poses numerous challenges for acoustic communication. Acoustic waves suffer long propagation delay, multipath, fading, and potentially high spatial and temporal variability. In addition, there is no typical underwater acoustic channel; every body of water exhibits quantifiably different properties. Underwater acoustic modems are traditionally operated at low frequencies. However, the use of broadband, high frequency communication is a good alternative because of the lower background noise compared to low-frequencies, considerably larger bandwidth and better source transducer efficiency. One of the biggest problems in the underwater acoustic communications at high frequencies is time-selective fading, resulting in the Doppler spread. While many Doppler detection, estimation and compensation techniques can be found in literature, the applications are limited to systems operating at low frequencies contained within frequencies ranging from a few hundred Hertz to around 30 kHz.
Show less - Date Issued
- 2015
- PURL
- http://purl.flvc.org/fau/fd/FA00004384, http://purl.flvc.org/fau/fd/FA00004384
- Subject Headings
- Adaptive signal processing, MIMO systems, Signal processing -- Ditigal techniques -- Mathematics, Underwater acoustic telemetry, Underwater acoustics -- Evaluation, Wireless communication systems
- 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
- Studies on transreceive diversity schemes (including "polarization-sense" antenna diversity) for wireless communication systems.
- Creator
- Preedalumpabut, Wichean., Florida Atlantic University, Neelakanta, Perambur S., Morgera, Salvatore D., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
The research addressed in this study and deliberated in the dissertation is broadly tied to finding hybrid methods of diversity compatible for modern wireless applications. The hybrid strategy advocated thereof involves a combined use of space- (antenna and polarization), frequency-, and time-diversity schemes in a judicious manner so as to realize a desirable BER versus Eb/No performance across RF links that face multipath and other unwanted EM artifacts. The underlying reason for the hybrid...
Show moreThe research addressed in this study and deliberated in the dissertation is broadly tied to finding hybrid methods of diversity compatible for modern wireless applications. The hybrid strategy advocated thereof involves a combined use of space- (antenna and polarization), frequency-, and time-diversity schemes in a judicious manner so as to realize a desirable BER versus Eb/No performance across RF links that face multipath and other unwanted EM artifacts. The underlying reason for the hybrid scheme as above is to replace multiple-antenna based transreceive diversity. Such multiple antennas would otherwise require large base station real estate and may not be compatible for hand-held (space-constrained) RF units. On the contrary, use of hybrid schemes would restrict multiple number of antennas and conserves the space. After analyzing a set of plausible techniques of hybrid diversity compatible for modern wireless techniques, a focused study has been done on polarization-sense (PS) antenna diversity scheme. Its fruitful application for indoor systems (like Bluetooth(TM)/ZigBee(TM)) against multipath effects is demonstrated via simulation and experimental studies. Further, the PS-antenna diversity is shown to offer improved BER versus Eb/N o performance in pilot channels used in CDMA2000 systems. Also, such PS-diversity is shown to help improving the GPS receiver performance under RFI/jamming environment. The technique and heuristics proposed towards the PS-antenna diversity scheme imply novel and hitherto unexplored efforts in wireless communications. Lastly the dissertation concludes summarizing the results and offers open-questions for further studies.
Show less - Date Issued
- 2004
- PURL
- http://purl.flvc.org/fcla/dt/12104
- Subject Headings
- Wireless communication systems, Antennas (Electronics)
- Format
- Document (PDF)
- Title
- Studies on Stochastic Multi-user Scheduling in Wireless Communication.
- Creator
- Wang, Di, Morgera, Salvatore D., Wang, Xin, Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
We developed a cross layer design which combines retransmission diversity and multi-user diversity for wireless communication. To this end, a joint design of adaptive modulation and coding with retransmission-based automatic repeat request protocol is outlined. This design is applied to devise multi-user scheduling schemes, which can optimally capture the available multi-user and retransmission diversities. In addition, the proposed on-line scheduling algorithms can operate even when the...
Show moreWe developed a cross layer design which combines retransmission diversity and multi-user diversity for wireless communication. To this end, a joint design of adaptive modulation and coding with retransmission-based automatic repeat request protocol is outlined. This design is applied to devise multi-user scheduling schemes, which can optimally capture the available multi-user and retransmission diversities. In addition, the proposed on-line scheduling algorithms can operate even when the underl ying fading channel distribution is unknown, while asymptotically converging to the offline benchmark with guarantees on prescribed fairness and rate requirements. Numerical results are provided to verify the merits of our novel schemes for multi-user transmissions over Nakagami block fading channels.
Show less - Date Issued
- 2008
- PURL
- http://purl.flvc.org/fau/fd/FA00012568
- Subject Headings
- Stochastic processes--Data processing, Wireless communication systems, Computer network protocols, Code division multiple access, Modulation (Electronics), Signal processing--Digital techniques
- Format
- Document (PDF)
- Title
- Stochastic optimization of energy for multi-user wireless networks over fading channels.
- Creator
- Wang, Di, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Wireless devices in wireless networks are powered typically by small batteries that are not replaceable nor recharged in a convenient way. To prolong the operating lifetime of networks, energy efficiency is indicated as a critical issue and energy-efficient resource allocation designs have been extensively developed. We investigated energy-efficient schemes that prolong network operating lifetime in wireless sensor networks and in wireless relay networks. In Chapter 2, the energy-efficient...
Show moreWireless devices in wireless networks are powered typically by small batteries that are not replaceable nor recharged in a convenient way. To prolong the operating lifetime of networks, energy efficiency is indicated as a critical issue and energy-efficient resource allocation designs have been extensively developed. We investigated energy-efficient schemes that prolong network operating lifetime in wireless sensor networks and in wireless relay networks. In Chapter 2, the energy-efficient resource allocation that minimizes a general cost function of average user powers for small- or medium-scale wireless sensor networks, where the simple time-division multiple-access (TDMA) is adopted as the multiple access scheme. A class of Ç-fair cost-functions is derived to balance the tradeoff between efficiency and fairness in energy-efficient designs. Based on such cost functions, optimal channel-adaptive resource allocation schemes are developed for both single-hop and multi-hop TDMA sensor networks. In Chapter 3, optimal power control methods to balance the tradeoff between energy efficiency and fairness for wireless cooperative networks are developed. It is important to maximize power efficiency by minimizing power consumption for a given quality of service, such as the data rate; it is also equally important to evenly or fairly distribute power consumption to all nodes to maximize the network life. The optimal power control policy proposed is derived in a quasi-closed form by solving a convex optimization problem with a properly chosen cost-function. To further optimize a wireless relay network performance, an orthogonal frequency division multiplexing (OFDM) based multi-user wireless relay network is considered in Chapter 4., In the OFDM approach, each subcarrier is dynamically assigned to a source- destination link, and several relays assist communication between pairs of source-destination over their assigned subcarriers. Using a class of Ç-fair cost-functions to balance the tradeoff between energy efficiency and fairness, jointly with optimal subcarrier and power allocation schemes at the relays. Relevant algorithms are derived in quasi-closed form. Lastly, the proposed energy-efficient schemes are summarized and future work is discussed in Chapter 5.
Show less - Date Issued
- 2011
- PURL
- http://purl.flvc.org/FAU/3322519
- Subject Headings
- Stochastic processes, Data processing, Wireless communication systems, Mathematical models, Computer network protocols, Signal processing, Digital techniques, Code division multiple access, Waveless division multiplexing, Orthogonalization methods
- 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
- Simulation-based performance evaluation of packet-switched H.264/AVC video streaming on WCDMA networks.
- Creator
- Murillo, Carlos A., Florida Atlantic University, Iskander, Cyril-Daniel, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
This thesis presents the simulation based performance evaluation on the transmission of multimedia services (H.264/AVC video streaming) to a mobile user over a packet-switched wireless network based on the WCDMA standard. The H.264/AVC refers to the codec, which is used as the main tool for video compression. It enables the transport of high bandwidth video data over Third Generation (3G) wireless systems by offering a high video compression rate, adaptability to the channel, and error...
Show moreThis thesis presents the simulation based performance evaluation on the transmission of multimedia services (H.264/AVC video streaming) to a mobile user over a packet-switched wireless network based on the WCDMA standard. The H.264/AVC refers to the codec, which is used as the main tool for video compression. It enables the transport of high bandwidth video data over Third Generation (3G) wireless systems by offering a high video compression rate, adaptability to the channel, and error resilience. It is transported using the RTP/UDP/IP protocol stack over the 3G wireless system. The WCDMA technology is simulated with special emphasis on the upper layers of the wireless channel. The performance of the WCDMA system is studied when transporting RTP/UDP/IP packets of H.264/AVC compressed video data under diverse configuration scenarios, namely, ARQ schemes and variable length of the transmitted frame at the link layer. These components of a packet-switched streaming service are integrated into a software simulation model, which is used to evaluate the end-to-end H.264/AVC video quality in a WCDMA wireless network.
Show less - Date Issued
- 2005
- PURL
- http://purl.flvc.org/fcla/dt/13291
- Subject Headings
- Wireless communication systems, Mobile communication systems, Global system for mobile communications, Code division multiple access, Streaming technology (Telecommunications)
- Format
- Document (PDF)
- Title
- Simulation-based performance evaluation of AODV routing protocol for ad hoc mobile wireless networks.
- Creator
- Suryaprasad, Deepa., Florida Atlantic University, Ilyas, Mohammad, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
An ad hoc wireless network is a network composed of mobile communication devices, which is designed to provide communication capability to satisfy the need of a temporary nature in an infrastructure-less environment. A routing protocol is necessary in ad hoc networks to ensure effective communication among nodes. This thesis presents a simulation-based study on the performance evaluation of Ad hoc on-demand distance vector (AODV) routing protocol, which is one of the core routing protocols...
Show moreAn ad hoc wireless network is a network composed of mobile communication devices, which is designed to provide communication capability to satisfy the need of a temporary nature in an infrastructure-less environment. A routing protocol is necessary in ad hoc networks to ensure effective communication among nodes. This thesis presents a simulation-based study on the performance evaluation of Ad hoc on-demand distance vector (AODV) routing protocol, which is one of the core routing protocols being promoted by the Mobile Ad Hoc Networking (MANET) group of the Internet Engineering Task Force. An event-advanced simulation program was developed in C++ to simulate the ad hoc wireless network implementing the AODV protocol. The performance metrics evaluated were throughput, average delay, route acquisition time and routing overhead. The network traffic was monitored in terms of the data packets created and successfully delivered within the simulation time. A discussion on the effect of different network parameters such as the mobility of the nodes, the number of nodes in the network, the size of the network and the data packet size on the performance characteristics of AODV protocol is also presented.
Show less - Date Issued
- 2003
- PURL
- http://purl.flvc.org/fcla/dt/12989
- Subject Headings
- Computer network protocols, Wireless communication systems
- Format
- Document (PDF)
- Title
- Simulation study of reservation scheme to improve the quality of service in wireless cellular network.
- Creator
- Chokshi, Patheek G., Florida Atlantic University, Ilyas, Mohammad
- Abstract/Description
-
In the present computer age, cellular technology and portable computers are becoming an integral part of the life. Each computer user wants to access the computing resources, irrespective of the location. Because of this need the computing paradigm "Mobile Computing" has assumed a primary role in modern computer communication technology. While dimensioning the network resources, it is very important to know how the users move around the geographical area covered by the cellular network. This...
Show moreIn the present computer age, cellular technology and portable computers are becoming an integral part of the life. Each computer user wants to access the computing resources, irrespective of the location. Because of this need the computing paradigm "Mobile Computing" has assumed a primary role in modern computer communication technology. While dimensioning the network resources, it is very important to know how the users move around the geographical area covered by the cellular network. This knowledge allows us to plan the system resources in order to achieve the QoS required. The major factors that affect the performance, along with the mobility pattern of the mobile user, are the speed at which the user is moving and the load on the network. In this research, we study different types of mobility patterns the user can follow and it's impact on the network services. We have proposed and evaluated a reservation scheme to improve the QoS in the cellular network. The reservation scheme reserves some part of the bandwidth for handoff connections. We have developed simulation programs and have studied three mobility patterns namely leading movement type, random motion, and square-street mobility pattern for measuring the QoS for cellular network. It has been observed from the results that at an average speed of 50 miles per hour with the average loading of the network, a significant improvement in QoS has been achieved for all the mobility patterns by using the reservation scheme.
Show less - Date Issued
- 1999
- PURL
- http://purl.flvc.org/fcla/dt/15706
- Subject Headings
- Wireless communication systems, Mobile computing, Cellular telephone systems
- Format
- Document (PDF)
- Title
- Simulation study of beacon time synchronization algorithm in low rate wireless personal area networks.
- Creator
- Shrivastav, Madhu., Florida Atlantic University, Mahgoub, Imad, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
In a beacon-enabled network, nodes send beacons when they are ready to transmit or receive messages from the other sensors in their communication range. If the beacons are not synchronized in time, a sensor might receive more than one beacon and hence will not be able to demodulate the beacon, thereby, being isolated from the network. As a result coverage nulls are introduced in the system. To address the above mentioned issues, Motorola Labs have proposed an algorithm for synchronizing the...
Show moreIn a beacon-enabled network, nodes send beacons when they are ready to transmit or receive messages from the other sensors in their communication range. If the beacons are not synchronized in time, a sensor might receive more than one beacon and hence will not be able to demodulate the beacon, thereby, being isolated from the network. As a result coverage nulls are introduced in the system. To address the above mentioned issues, Motorola Labs have proposed an algorithm for synchronizing the beacons in a wireless personal area network. In this thesis, extensive study of the proposed beacon time synchronization algorithm is done using OPNET as a simulation tool. Simulation is carried out by designing a detailed model of the algorithm using IEEE 802.15.4 as a reference. In depth analysis of the simulation results has been carried out. The results obtained are compared with those of existing time synchronization methods.
Show less - Date Issued
- 2005
- PURL
- http://purl.flvc.org/fcla/dt/13227
- Subject Headings
- Wireless LANs, Extranets (Computer networks), Wireless communication systems, Data transmission systems, Computer network protocols, Home computer networks
- 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
- Scheduling for composite event detection in wireless sensor networks.
- Creator
- Ambrose, Arny Isonja, Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Wireless sensor networks are used in areas that are inaccessible, inhospitable or for continuous monitoring. The main use of such networks is for event detection. Event detection is used to monitor a particular environment for an event such as fire or flooding. Composite event detection is used to break down the detection of the event into the specific conditions that need to be present for the event to occur. Using this method, each sensor node does not need to carry every sensing component...
Show moreWireless sensor networks are used in areas that are inaccessible, inhospitable or for continuous monitoring. The main use of such networks is for event detection. Event detection is used to monitor a particular environment for an event such as fire or flooding. Composite event detection is used to break down the detection of the event into the specific conditions that need to be present for the event to occur. Using this method, each sensor node does not need to carry every sensing component necessary to detect the event. Since energy efficiency is important the sensor nodes need to be scheduled so that they consume [sic] consume as little energy as possible to extend the network lifetime. In this thesis, a solution to the sensor Scheduling for Composite Event Detection (SCED) problem will be presented as a way to improve the network lifetime when using composite event detection.
Show less - Date Issued
- 2008
- PURL
- http://purl.flvc.org/fcla/dt/186333
- Subject Headings
- Sensor networks, Wireless communication systems, Embedded computer systems, Computer systems, Reliability
- Format
- Document (PDF)
- Title
- Reputation-based system for encouraging cooperation of nodes in mobile ad hoc networks.
- Creator
- Anantvalee, Tiranuch., Florida Atlantic University, Wu, Jie
- Abstract/Description
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In a mobile ad hoc network, node cooperation in packet forwarding is required for the network to function properly. However, since nodes in this network usually have limited resources, some selfish nodes might intend not to forward packets to save resources for their own use. To discourage such behavior, we propose RMS, a reputation-based system, to detect selfish nodes and respond to them by showing that being cooperative will benefit there more than being selfish. We also detect, to some...
Show moreIn a mobile ad hoc network, node cooperation in packet forwarding is required for the network to function properly. However, since nodes in this network usually have limited resources, some selfish nodes might intend not to forward packets to save resources for their own use. To discourage such behavior, we propose RMS, a reputation-based system, to detect selfish nodes and respond to them by showing that being cooperative will benefit there more than being selfish. We also detect, to some degree, nodes who forward only the necessary amount of packets to avoid being detected as selfish. We introduce the use of a state model to decide what we should do or respond to nodes in each state. In addition, we introduce the use of a timing period to control when the reputation should be updated and to use as a timeout for each state. The simulation results show that RMS can identify selfish nodes and punish them accordingly, which provide selfish nodes with an incentive to behave more cooperatively.
Show less - Date Issued
- 2006
- PURL
- http://purl.flvc.org/fcla/dt/13406
- Subject Headings
- Computer networks--Security measures, Wireless communication systems, Routers (Computer networks), Computer network architectures
- Format
- Document (PDF)
- Title
- Reputation and trust-based security in wireless sensor networks.
- Creator
- Srinivasan, Avinash., College of Engineering and Computer Science, Florida Atlantic University, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
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This dissertation presents the results of research that led to the development of a novel reputation and trust-based monitoring paradigm for secure and reliable computing in Wireless Sensor Networks (WSNs). WSNs have undergone tremendous technological advances over the last few years. They have caused a giant leap toward "proactive computing," a paradigm where computers anticipate human needs and, when necessary, act on their behalf. Therefore, we cannot deploy such a critical technology...
Show moreThis dissertation presents the results of research that led to the development of a novel reputation and trust-based monitoring paradigm for secure and reliable computing in Wireless Sensor Networks (WSNs). WSNs have undergone tremendous technological advances over the last few years. They have caused a giant leap toward "proactive computing," a paradigm where computers anticipate human needs and, when necessary, act on their behalf. Therefore, we cannot deploy such a critical technology without first addressing the security and privacy challenges to ensure that it does not turn against those whom it is meant to benefit. The core application of WSNs is to detect and report events, be it military or civilian applications. The building blocks of a WSN are small, battery-powered, lowcost, self-contained devices called "sensors" that measure factors like light, temperature, pressure, vibration, motion, etc. A WSN usually consists of hundreds of thousands of sensors that operate in unattended, hostile territories to monitor a given geographical area. Once deployed, the wireless sensors self-organize into ad-hoc wireless networks in order to cope with the dynamics of the surveillance field. During the post deployment phase, the wireless sensors aggregate data, then process and generate a report, which is subsequently relayed from one sensor to the next using secure multi-hop routing until the data reaches its desired destination, which is usually the sink. Since sensors operate in unattended and hostile territories, the adversary can capture a sensor node physically and extract all the information stored onboard, including cryptographic keying material. With this unique situation, WSNs are subject to a unique attack referred to as an "Insider Attack," in which the adversary becomes a legitimate member of the network being represented by the captured node., To overcome this unique situation, a distributed Reputation and Trust-based Monitoring System (RTMS) is required. The most critical contribution of this dissertation work has been the proposal and design of a novel, clique-based, distributed group-key establishment protocol with specific application to RTMSs. We have also proposed and evaluated the application of RTMS models for securing beacon-based localization in WSNs addressing information asymmetry attacks, and proposed a novel k-parent tree model for securing broadcast communication in WSNs with an underlying RTMS model. Other issues addressed in this dissertation work include the proposal of a Connected Dominating Set (CDS) based reputation dissemination and bootstrapping model. This model also enables secure, certificateless node mobility and enables the model to be robust to ID Spoofing and node replication attacks.
Show less - Date Issued
- 2008
- PURL
- http://purl.flvc.org/FAU/77652
- Subject Headings
- Sensor networks, Security measures, Wireless communication systems, Security measures, Wireless communication systems, Technological innovations, Ad hoc networks (Computer networks), Security measures
- Format
- Document (PDF)
- Title
- Remote gaming on resource constrained devices.
- Creator
- Reza, Waazim., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
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Games have become important applications on mobile devices. A mobile gaming approach known as remote gaming is being developed to support games on low cost mobile devices. In the remote gaming approach, the responsibility of rendering a game and advancing the game play is put on remote servers instead of the resource constrained mobile devices. The games rendered on the servers are encoded as video and streamed to mobile devices. Mobile devices gather user input and stream the commands back...
Show moreGames have become important applications on mobile devices. A mobile gaming approach known as remote gaming is being developed to support games on low cost mobile devices. In the remote gaming approach, the responsibility of rendering a game and advancing the game play is put on remote servers instead of the resource constrained mobile devices. The games rendered on the servers are encoded as video and streamed to mobile devices. Mobile devices gather user input and stream the commands back to the servers to advance game play. With this solution, mobile devices with video playback and network connectivity can become game consoles. In this thesis, we present the design and development of such a system and evaluate the performance and design considerations to maximize the end user gaming experience. A gaming user experience model capable of predicting the user experience for a given gaming session is developed and verified.
Show less - Date Issued
- 2010
- PURL
- http://purl.flvc.org/FAU/2978944
- Subject Headings
- Wireless communication systems, Mobile communication systems, Mobie computing, Programming, Application software, Development, Game theory, Mobile commerce
- Format
- Document (PDF)
- Title
- Reliable, energy-aware cross-layer protocol for wireless sensor networks.
- Creator
- Badi, Ahmed., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
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This research addresses communication reliability in the highly constrained wireless sensor networks environment. We propose a cross-layer, reliable wireless sensor protocol design. The protocol benefits from the body of research in the two areas of wireless sensors reliability research and wireless sensors energy conservation research. The protocol introduces a new energy saving technique that considers reliability as a design parameter and constraint. The protocol also introduces a new back...
Show moreThis research addresses communication reliability in the highly constrained wireless sensor networks environment. We propose a cross-layer, reliable wireless sensor protocol design. The protocol benefits from the body of research in the two areas of wireless sensors reliability research and wireless sensors energy conservation research. The protocol introduces a new energy saving technique that considers reliability as a design parameter and constraint. The protocol also introduces a new back-off algorithm that dynamically adjusts to the data messages reliability needs. Other cross-layer techniques that the protocol introduces are dynamic MAC retry limit and dynamic transmission power setting that is also based on the messages reliability requirements. Cross layer design is defined as the interaction between the different stack layers with the goal of improving performance. It has been used in ad hoc wireless systems to improve throughput, latency, and quality of service (QoS). The improvements gained in performance come at a price. This includes decreased architecture modularity and designs may be hard to debug, maintain or upgrade. Cross-layer design is valuable for wireless sensor networks due to the severe resource constraints. The proposed protocol uses cross-layer design as a performance and energy optimization technique. Nevertheless, the protocol avoids introducing layer interdependencies by preserving the stack architecture and optimizes the overall system energy and reliability performance by information sharing. The information is embedded as flags in the data and control messages that are moving through the stack. Each layer reads these flags and adjusts its performance and handling of the message accordingly. The performance of the proposed protocol is evaluated using simulation modeling. The reference protocol used for evaluation is APTEEN., We developed simulation programs for the proposed protocol and for APTEEN protocol using the JiST/SWANS simulation tool. The performance evaluation results show that the proposed protocol achieves better energy performance than the reference protocol. Several scalability experiments show that the proposed protocol scales well and has better performance for large networks. Also, exhaustive bandwidth utilization experiments show that for heavily-utilized or congested networks, the proposed protocol has high reliability in delivering messages classified as important.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/359921
- Subject Headings
- Computer network protocols, Wireless communication systems, Technological innovations, Sensor networks, Power resources, Efficiency
- Format
- Document (PDF)