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- Title
- Adaptive on-demand routing protocol for mobile ad hoc networks.
- Creator
- Omer, Ismail., Florida Atlantic University, Mahgoub, Imad, Ilyas, Mohammad, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Existing MANET routing protocols can be classified into three categories: On-demand, Proactive, and Proactive-On-demand hybrid protocols. This dissertation presents a novel hybrid MANET routing protocol, Adaptive On-demand MANET Routing (AOMAR) protocol. AOMAR borrowed the concepts of temporal location updates in operating systems and cache memories to reconstruct broken routes. Each route entry in a mobile host will have a reference field that is set to indicate whether the route is used...
Show moreExisting MANET routing protocols can be classified into three categories: On-demand, Proactive, and Proactive-On-demand hybrid protocols. This dissertation presents a novel hybrid MANET routing protocol, Adaptive On-demand MANET Routing (AOMAR) protocol. AOMAR borrowed the concepts of temporal location updates in operating systems and cache memories to reconstruct broken routes. Each route entry in a mobile host will have a reference field that is set to indicate whether the route is used within a certain period of time called refresh time. Using the refresh time parameter and the route reference field, AOMAR behavior can be controlled to behave as pure On-demand, Adaptive, or history related Proactive protocol. The three versions of AOMAR, On-demand, Adaptive and Proactive, have been simulated using different network sizes, loads and mobility patterns. Three performance metrics---throughput, delay and overhead---are collected. The results show that AOMAR on-demand has the same pattern of results when compared with other exiting on-demand protocols. On-demand AOMAR shows better performance when compared to Adaptive AOMAR for simulation sessions with uniform workloads. On the other hand Adaptive AOMAR outperforms On-demand AOMAR for simulation sessions with non-uniform workloads. Proactive AOMAR reconstructs recently used routes that have broken. Therefore, its routing overhead results change with the change of the network loads and mobility rates. This is not the case for traditional proactive protocols. Proactive AOMAR has lower control overhead and saves the bandwidth when compared with traditional existing proactive routing protocols. In addition to developing and simulating AOMAR, a new mobility model is proposed. Synchronized Random Direction Model of Motion with Constant Speed (SRDMCS) is a model that is suitable to emulate objects that move in random directions with a constant speed and within a certain area of movement. A new formula, Movement Related Update (MRU), is proposed and implemented. In MRU, the refresh period parameter value is linked to the network mobility level. Using MRU in the simulation gives AOMAR a third dimension such that the protocol not only adapts with how frequently the routes are used and how frequently they are broken, but also with how dynamic the network is.
Show less - Date Issued
- 2001
- PURL
- http://purl.flvc.org/fcla/dt/11972
- Subject Headings
- Mobile computing, Computer network protocols, Wireless communication systems
- Format
- Document (PDF)
- Title
- Analysis of quality of service (QoS) in WiMAX networks.
- Creator
- Talwalkar, Rohit., College of Engineering and Computer Science, Florida Atlantic University, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
In last few years there has been significant growth in the area of wireless communication. Quality of Service (QoS) has become an important consideration for supporting variety of applications that utilize the network resources. These applications include voice over IP, multimedia services, like, video streaming, video conferencing etc. IEEE 802.16/WiMAX is a new network which is designed with quality of service in mind. This thesis focuses on analysis of quality of service as implemented by...
Show moreIn last few years there has been significant growth in the area of wireless communication. Quality of Service (QoS) has become an important consideration for supporting variety of applications that utilize the network resources. These applications include voice over IP, multimedia services, like, video streaming, video conferencing etc. IEEE 802.16/WiMAX is a new network which is designed with quality of service in mind. This thesis focuses on analysis of quality of service as implemented by the WiMAX networks. First, it presents the details of the quality of service architecture in WiMAX network. In the analysis, a WiMAX module developed based on popular network simulator ns-2, is used. Various real life scenarios like voice call, video streaming are setup in the simulation environment. Parameters that indicate quality of service, such as, throughput, packet loss, average jitter and average delay, are analyzed for different types of service flows as defined in WiMAX. Results indicate that better quality of service is achieved by using service flows designed for specific applications.
Show less - Date Issued
- 2008
- PURL
- http://purl.flvc.org/fcla/flaent/EN00154040/68_2/98p0143h.pdf, http://purl.flvc.org/FAU/58012
- Subject Headings
- Wireless communication systems, Broadband communication systems, Wireless LANs, Design and construction, Computer networks, Management, Quality control
- Format
- Document (PDF)
- Title
- Channel assignment in multi-radio networks.
- Creator
- Mihnea, Amalya, Cardei, Mihaela, Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Channel assignment in multi-radio networks is a topic of great importance because the use of multiple channels and multiple radios reduces interference and increases the network throughput. The goal of our research is to design algorithms that maximize the use of available resources while providing robustness to primary users that could reclaim one or more channels. Our algorithms could be used in ad hoc networks, mesh networks, and sensor networks where nodes are equipped with multiple...
Show moreChannel assignment in multi-radio networks is a topic of great importance because the use of multiple channels and multiple radios reduces interference and increases the network throughput. The goal of our research is to design algorithms that maximize the use of available resources while providing robustness to primary users that could reclaim one or more channels. Our algorithms could be used in ad hoc networks, mesh networks, and sensor networks where nodes are equipped with multiple radios. We design algorithms for channel assignment which provide robustness to primary users without assuming an accurate primary user behavior model. We also compute bounds for capacity in grid networks and discuss how the capacity of a network changes when multiple channels are available. Since preserving energy is very important in wireless networks, we focus on algorithms that do not require powerful resources and which use a reduced number of messages.
Show less - Date Issued
- 2015
- PURL
- http://purl.flvc.org/fau/fd/FA00004393, http://purl.flvc.org/fau/fd/FA00004393
- Subject Headings
- Adaptive signal processing, Long Term Evolution (Telecommunications), MIMO systems, Mobile communication systems, Wireless communication systems, Wireless sensor networks
- Format
- Document (PDF)
- Title
- Combined spatial diversity and time equalization for broadband multiple channel underwater acoustic communications.
- Creator
- Skoro Kaskarovska, Violeta, Beaujean, Pierre-Philippe, Florida Atlantic University, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
High data rate acoustic communications become feasible with the use of communication systems that operate at high frequency. The high frequency acoustic transmission in shallow water endures severe distortion as a result of the extensive intersymbol interference and Doppler shift, caused by the time variable multipath nature of the channel. In this research a Single Input Multiple Output (SIMO) acoustic communication system is developed to improve the reliability of the high data rate...
Show moreHigh data rate acoustic communications become feasible with the use of communication systems that operate at high frequency. The high frequency acoustic transmission in shallow water endures severe distortion as a result of the extensive intersymbol interference and Doppler shift, caused by the time variable multipath nature of the channel. In this research a Single Input Multiple Output (SIMO) acoustic communication system is developed to improve the reliability of the high data rate communications at short range in the shallow water acoustic channel. The proposed SIMO communication system operates at very high frequency and combines spatial diversity and decision feedback equalizer in a multilevel adaptive configuration. The first configuration performs selective combining on the equalized signals from multiple receivers and generates quality feedback parameter for the next level of combining.
Show less - Date Issued
- 2015
- PURL
- http://purl.flvc.org/fau/fd/FA00004411, http://purl.flvc.org/fau/fd/FA00004411
- Subject Headings
- Adaptive signal processing, MIMO systems, Mobile geographic information systems, Signal processing -- Digital techniques, Underwater acoustic telemetry, Underwater acoustics -- Evaluation, Wireless communication systems
- Format
- Document (PDF)
- Title
- A communication protocol for wireless sensor networks.
- Creator
- Callaway, Edgar Herbert, Jr., Florida Atlantic University, Shankar, Ravi, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Many wireless network applications, such as wireless computing on local area networks, employ data throughput as a primary performance metric. The data throughput on such networks has therefore been increasing in recent years. However, there are other potential wireless network applications, such as industrial monitoring and control, consumer home automation, and military remote sensing, that have relaxed throughput requirements, often measured in bits/day. Such networks have power...
Show moreMany wireless network applications, such as wireless computing on local area networks, employ data throughput as a primary performance metric. The data throughput on such networks has therefore been increasing in recent years. However, there are other potential wireless network applications, such as industrial monitoring and control, consumer home automation, and military remote sensing, that have relaxed throughput requirements, often measured in bits/day. Such networks have power consumption and cost as primary performance metrics, rather than data throughput, and have been called wireless sensor networks. This work describes a physical layer, a data link layer, and a network layer design suitable for use in wireless sensor networks. To minimize node duty cycle and therefore average power consumption, while minimizing the symbol rate, the proposed physical layer employs a form of orthogonal multilevel signaling in a direct sequence spread spectrum format. Results of Signal Processing Worksystem (SPW, Cadence, Inc.) simulations are presented showing a 4-dB sensitivity advantage of the proposed modulation method compared to binary signaling, in agreement with theory. Since the proposed band of operation is the 2.4 GHz unlicensed band, interference from other services is possible; to address this, SPW simulations of the proposed modulation method in the presence of Bluetooth interference are presented. The processing gain inherent in the proposed spread spectrum scheme is shown to require the interferer to be significantly stronger than the desired signal before materially affecting the received bit error rate. The proposed data link layer employs a novel distributed mediation device (MD) technique to enable networked nodes to synchronize to each other, even when the node duty cycle is arbitrarily low (e.g., <0.1%). This technique enables low-cost devices, which may employ only low-stability time bases, to remain asynchronous to one another, becoming synchronized only when communication is necessary between them. Finally, a wireless sensor network design is presented. A cluster-type architecture is chosen; the clusters are organized in a hierarchical tree to simplify the routing algorithm. Results of several network performance metrics simulations, including the effects of the distributed MD dynamic synchronization scheme, are presented, including the average message latency, node duty cycle, and data throughput. The architecture is shown to represent a practical alternative for the design of wireless sensor networks.
Show less - Date Issued
- 2002
- PURL
- http://purl.flvc.org/fcla/dt/11991
- Subject Headings
- Wireless communication systems, Computer network protocols, Radio detectors
- Format
- Document (PDF)
- Title
- Design and implementation of a wireless ad hoc network.
- Creator
- Neelakanta, Mahesh., Florida Atlantic University, Hsu, Sam, Ilyas, Mohammad, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
This thesis addresses issues faced in the practical implementation of a wireless ad hoc network (WAHN) protocol for data transmission. This study focuses on: (1) Evaluating existing hardware and software options available for the WAHN implementation. (2) Appraising the issues faced while implementing a practical wireless ad hoc protocol. (3) Applying a set of MAC protocol specifications developed for a wireless ad hoc data network to a practical test network. Specific to the above topics of...
Show moreThis thesis addresses issues faced in the practical implementation of a wireless ad hoc network (WAHN) protocol for data transmission. This study focuses on: (1) Evaluating existing hardware and software options available for the WAHN implementation. (2) Appraising the issues faced while implementing a practical wireless ad hoc protocol. (3) Applying a set of MAC protocol specifications developed for a wireless ad hoc data network to a practical test network. Specific to the above topics of interest, the following research tasks are performed: (1) An elaborate survey and relevant discussions on wireless MAC protocols. (2) A comprehensive study comparing various wireless transceivers is performed. Range, data rate, frequency, interfacing method and cost are the factors compared. (3) A simple, low-cost and low baud-rate transceiver is modified with appropriate interface circuits to support wireless communications. A more advanced transceiver is also considered and used for the software foundation of a practical implementation of the ad hoc and MAC protocols. The studies enable assessing the problems faced during the implementation and suggest solutions to resolve these problems. Further areas for study are also discussed.
Show less - Date Issued
- 1998
- PURL
- http://purl.flvc.org/fcla/dt/15615
- Subject Headings
- Wireless communication systems, Data transmission systems, Computer networks
- Format
- Document (PDF)
- Title
- Design and implementation of an energy model for JiST/SWANS simulator.
- Creator
- Sutaria, Trishla., Florida Atlantic University, Mahgoub, Imad, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Wireless sensor networks are one of the first real world examples of pervasive computing, the notion that small, smart, and cheap sensing and computing devices will eventually permeate the environment. Sensor networks consist of very large number of energy constrained nodes and to properly evaluate these networks a scalable ad-hoc wireless network simulator with an energy model is needed. Since most of the existing simulators have been designed for ad-hoc network with low scalability they can...
Show moreWireless sensor networks are one of the first real world examples of pervasive computing, the notion that small, smart, and cheap sensing and computing devices will eventually permeate the environment. Sensor networks consist of very large number of energy constrained nodes and to properly evaluate these networks a scalable ad-hoc wireless network simulator with an energy model is needed. Since most of the existing simulators have been designed for ad-hoc network with low scalability they can not be used to accurately simulate sensor networks. The JiST/SWANS simulator is one of the newer simulators that has been developed by Cornell University for simulating ad-hoc networks and is highly scalable which makes it appropriate for use in evaluating sensor networks. Since this simulator lack energy model our objective is to design and implement an energy model for JiST/SWANS so that it can adequately and accurately calculate the amount of energy consumption in the simulation of sensor networks.
Show less - Date Issued
- 2005
- PURL
- http://purl.flvc.org/fcla/dt/13275
- Subject Headings
- Sensor networks, Wireless LANs, Computer network protocols, Wireless communication systems
- Format
- Document (PDF)
- Title
- Design and implementation of efficient routing protocols in delay tolerant networks.
- Creator
- Liu, Cong., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Delay tolerant networks (DTNs) are occasionally-connected networks that may suffer from frequent partitions. DTNs provide service despite long end to end delays or infrequent connectivity. One fundamental problem in DTNs is routing messages from their source to their destination. DTNs differ from the Internet in that disconnections are the norm instead of the exception. Representative DTNs include sensor-based networks using scheduled intermittent connectivity, terrestrial wireless networks...
Show moreDelay tolerant networks (DTNs) are occasionally-connected networks that may suffer from frequent partitions. DTNs provide service despite long end to end delays or infrequent connectivity. One fundamental problem in DTNs is routing messages from their source to their destination. DTNs differ from the Internet in that disconnections are the norm instead of the exception. Representative DTNs include sensor-based networks using scheduled intermittent connectivity, terrestrial wireless networks that cannot ordinarily maintain end-to-end connectivity, satellite networks with moderate delays and periodic connectivity, underwater acoustic networks with moderate delays and frequent interruptions due to environmental factors, and vehicular networks with cyclic but nondeterministic connectivity. The focus of this dissertation is on routing protocols that send messages in DTNs. When no connected path exists between the source and the destination of the message, other nodes may relay the message to the destination. This dissertation covers routing protocols in DTNs with both deterministic and non-deterministic mobility respectively. In DTNs with deterministic and cyclic mobility, we proposed the first routing protocol that is both scalable and delivery guaranteed. In DTNs with non-deterministic mobility, numerous heuristic protocols are proposed to improve the routing performance. However, none of those can provide a theoretical optimization on a particular performance measurement. In this dissertation, two routing protocols for non-deterministic DTNs are proposed, which minimizes delay and maximizes delivery rate on different scenarios respectively. First, in DTNs with non-deterministic and cyclic mobility, an optimal single-copy forwarding protocol which minimizes delay is proposed., In DTNs with non-deterministic mobility, an optimal multi-copy forwarding protocol is proposed. which maximizes delivery rate under the constraint that the number of copies per message is fixed . Simulation evaluations using both real and synthetic trace are conducted to compare the proposed protocols with the existing ones.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/210522
- Subject Headings
- Computer network protocols, Computer networks, Reliability, Computer algorithms, Wireless communication systems, Technological innovations
- Format
- Document (PDF)
- Title
- Diversity performance of DS-CDMA systems in multipath fading channels.
- Creator
- Efthymoglou, George P., Florida Atlantic University, Helmken, Henry, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
In this dissertation, new semi-analytical expressions for the diversity bit error rate performance of asynchronous direct sequence-code division multiple access (DS-CDMA) systems in multipath fading channels are derived. Also, the PN acquisition time of a DS system with offset frequency periods greater than the code period in a AWGN channel is measured via laboratory experiments. In Part I we consider DS-CDMA systems operating in a cellular environment with multipath reception. Multipath...
Show moreIn this dissertation, new semi-analytical expressions for the diversity bit error rate performance of asynchronous direct sequence-code division multiple access (DS-CDMA) systems in multipath fading channels are derived. Also, the PN acquisition time of a DS system with offset frequency periods greater than the code period in a AWGN channel is measured via laboratory experiments. In Part I we consider DS-CDMA systems operating in a cellular environment with multipath reception. Multipath propagation is exploited through the use of RAKE receivers. Coherent, differentially coherent and noncoherent binary demodulation schemes are considered. The multiple access interference is modeled as AWGN, conditioned on the fading statistics of the received signal. The mobile radio channel introduces selective fading, and is modeled as a tapped delay line. The amplitude of each resolvable path is statistically described by the Nakagami distribution, which is a general solution to the random vector problem that causes rapid fading. However, we assume independent but nonidentical fading along the RAKE branches. Therefore our analysis supports unequal mean powers and different amount of fading in the multipath components combined by the receiver. Also, the results can be easily extended to account for diversity from multiple antennas or coding in the generalized Nakagami multipath fading environment. In Part II we consider a land mobile satellite channel. First, a laboratory experiment is setup to evaluate the PN acquisition performance of a digital IF receiver in a AWGN channel with large Doppler offset. The digital conversion receiver uses the inherent aliasing property of sampling to realize the baseband conversion using a single analog-to-digital converter. Thereafter, digital signal processing on the I and Q samples enable for design trade-offs in the acquisition of the PN code with Doppler periods greater than the code period. Two code phase selection criterions, namely the maximum criterion and the threshold crossing criterion, are investigated and their acquisition time is measured for different frequency offsets and input IF signal to noise ratios. We also derive semi-analytical expressions for the BER performance of coherent and differentially coherent systems operating in a mobile satellite channel. In this case the channel is modeled as a multipath nonselective channel, but diversity gain can still be obtained through path diversity. This is the scenario when a signal is transmitted to all satellites in view and the received replicas are independently demodulated and combined at the receiver. Our analysis extends previous results to the case of unequal mean powers and Rice factors in the combined signals; a valid assumption if we consider that the satellites are in view at different elevation angles. Furthermore, the effect of imperfect power control in such mobile satellite DS-CDMA systems is also considered.
Show less - Date Issued
- 1997
- PURL
- http://purl.flvc.org/fcla/dt/12516
- Subject Headings
- Mobile communication systems, Wireless communication systems, Radio wave propagation
- Format
- Document (PDF)
- Title
- Diversity techniques in direct sequence code division multiple access communication systems.
- Creator
- Ugweje, Okechukwu Clark., Florida Atlantic University, Aalo, Valentine A., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
This dissertation investigates the performance of different space diversity combining techniques for the wireless mobile communication systems employing Direct Sequence-Code Division Multiple Access (DS-CDMA). It covers two research topics, all falling under the umbrella of diversity combining techniques. The first part deals with diversity reception of wideband DS-CDMA signals in which the diversity branches experience some correlation. This analysis is performed without the usual assumption...
Show moreThis dissertation investigates the performance of different space diversity combining techniques for the wireless mobile communication systems employing Direct Sequence-Code Division Multiple Access (DS-CDMA). It covers two research topics, all falling under the umbrella of diversity combining techniques. The first part deals with diversity reception of wideband DS-CDMA signals in which the diversity branches experience some correlation. This analysis is performed without the usual assumption that diversity branches are independent and hence uncorrelated. In this case, the analysis is limited to the conventional diversity techniques such as maximal ratio combining, equal gain combining and selection diversity. In particular, the effect of correlation on system performance using two correlation profiles namely, the constant and the exponential correlation profiles is explored. In the constant correlation, the correlation between adjacent antenna are equal regardless of the separation between them, while in exponential correlation, it is assumed that the level of correlation between adjacent antennas decreases as their separation increases. The second topic deals with the development of new combining techniques. Two new techniques--the Generalized Selection Diversity Combining (GSDC) and the Maximal Ratio-Selection Diversity Combining (MR-SDC)--are introduced and analyzed in this dissertation. Analytical models which can be used to evaluate the performance of these new techniques are indicated. Results show that GSDC perform significantly better than the conventional selection diversity when two or more larger signals are selected. The MR-SDC technique accounts for the possibility of using a large array of antennas and for occasions when the receiving antennas may not be collocated. Also, it is shown that for the large array of antennas, better performance is achieved when the MR-SDC is employed with the maximum number of subgroups. The figures of merit used in this dissertation are the average Bit Error Rate (BER) and the probability of outage for a given threshold probability of error. Exact and approximate expressions are derived for the average bit error probability as well as for the outage probability while accounting for the effect of multipath fading, multiple access interference and background noise.
Show less - Date Issued
- 1997
- PURL
- http://purl.flvc.org/fcla/dt/12524
- Subject Headings
- Code division multiple access, Wireless communication systems
- Format
- Document (PDF)
- Title
- EM polarization measurement campaign and its applications.
- Creator
- Pollard, Ritsuko Hamahata, Florida Atlantic University, Helmken, Henry, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Due to a continuous growth of demand in voice and data communications for wireless systems, there is an ongoing challenge to design improved radiowave communication links. Polarization is one of the key properties of electromagnetic waves used in wireless communication and is the least studied in a scattering environment. A detailed understanding of how signals become de-polarized can improve the propagation models and can lead to more accurate propagation predictions and possibly new...
Show moreDue to a continuous growth of demand in voice and data communications for wireless systems, there is an ongoing challenge to design improved radiowave communication links. Polarization is one of the key properties of electromagnetic waves used in wireless communication and is the least studied in a scattering environment. A detailed understanding of how signals become de-polarized can improve the propagation models and can lead to more accurate propagation predictions and possibly new applications in the use of polarization. Potential beneficiaries of a system design using multi-dimensional polarization constellations to provide maximum polarization separation might include inter-satellite links, WLAN, LEO satellites [BSPP92] [IPLJ81] [SIKA98] and other systems operating in an environment where depolarization is insignificant. To examine the applicability of polarization in wireless communication systems, polarization field measurements were conducted, and the results and analysis are presented in this dissertation. Based on the analysis, a statistical model that characterizes polarization in relation to Poincare sphere is developed and presented. Design and implementation of an N-constellation diversity scheme that provides maximum polarization separation distance is presented. Furthermore, a decision-making algorithm is utilized for detection of the received electric field that selects the minimum Euclidian distance between the transmitter and receivers in Stokes space. The scenario is simulated for an N-constellation scheme for N = 2, 3, 4 based on the design scheme utilizing the developed statistical model and decision-making algorithm and is used to evaluate the detectability and performance comparison for various values of standard deviations.
Show less - Date Issued
- 2004
- PURL
- http://purl.flvc.org/fau/fd/FADT12089
- Subject Headings
- Electromagnetic waves--Polarization, Wireless communication systems
- Format
- Document (PDF)
- Title
- Energy-efficient protocols for wireless sensor networks.
- Creator
- Du, Kemei., Florida Atlantic University, Wu, Jie
- Abstract/Description
-
This thesis describes energy-conserving techniques in wireless sensor networks. In wireless sensor networks the sensor nodes gather information and send the information to a base station periodically. Some important messages need be broadcast to all nodes. Due to the limited battery capacity in sensor nodes, energy efficiency is becoming a major challenging problem in these power-constrained networks. Chain-based protocols construct a transmission chain connecting all nodes to save energy...
Show moreThis thesis describes energy-conserving techniques in wireless sensor networks. In wireless sensor networks the sensor nodes gather information and send the information to a base station periodically. Some important messages need be broadcast to all nodes. Due to the limited battery capacity in sensor nodes, energy efficiency is becoming a major challenging problem in these power-constrained networks. Chain-based protocols construct a transmission chain connecting all nodes to save energy dissipation of data transmission. We propose a multiple-chain scheme for all-to-all broadcasting. Furthermore, we develop an energy-efficient chain-construction algorithm which uses a sequence of insertions to minimize the energy consumption along the chain. We propose an energy-based adaptive clustering protocol, in which cluster-head elections depend on not only a probabilistic model but also the remaining energy in each node. This protocol improves the life time of the network by distributing energy usage effectively among the sensor nodes.
Show less - Date Issued
- 2002
- PURL
- http://purl.flvc.org/fcla/dt/12912
- Subject Headings
- Wireless communication systems, Computer network protocols
- Format
- Document (PDF)
- Title
- Energy-efficient routing in ad hoc wireless networks.
- Creator
- Dai, Qing., Florida Atlantic University, Wu, Jie
- Abstract/Description
-
The ad hoc wireless network is an infrastructureless network, where mobile stations are typically powered by batteries. Energy conservation has therefore becomes a very important issue. In this thesis, we discuss our work on several problems in energy-efficient routing. Chapter 3 focuses on how to compute the minimum uniform broadcast transmission power in an ad hoc wireless network. Several algorithms are proposed and their running time compared through simulation. It is shown that Prim's...
Show moreThe ad hoc wireless network is an infrastructureless network, where mobile stations are typically powered by batteries. Energy conservation has therefore becomes a very important issue. In this thesis, we discuss our work on several problems in energy-efficient routing. Chapter 3 focuses on how to compute the minimum uniform broadcast transmission power in an ad hoc wireless network. Several algorithms are proposed and their running time compared through simulation. It is shown that Prim's Minimum Spanning Tree (MST) has better performance than Kruskal's MST and the two binary search algorithms. In the following two chapters, routing algorithms are studied for specific situations, when directional antenna is used (Chapter 4) or when partial signal could be collected, stored and integrated (Chapter 5). Different algorithms are discussed and their energy performance illustrated by simulation study. Their application and limitation are also discussed in the thesis.
Show less - Date Issued
- 2003
- PURL
- http://purl.flvc.org/fcla/dt/13077
- Subject Headings
- Wireless communication systems, Routers (Computer networks), Electronic digital computers--Power supply, Mobile computing
- Format
- Document (PDF)
- Title
- Energy-efficient target coverage in heterogeneous wireless sensor networks.
- Creator
- Awada, Wael, Florida Atlantic University, Cardei, Mihaela
- Abstract/Description
-
We consider a heterogeneous wireless sensor network, which has several supernodes for data relay and a large number of energy-constrained sensor nodes that are deployed randomly to cover certain targets. Since targets are covered by many sensors, we create several cover sets that are active successively to save power. We introduce the Heterogeneous Connected Set Covers (HCSC) which aims to find at least one cover set that covers all the targets and is connected to a data-relaying supernode. A...
Show moreWe consider a heterogeneous wireless sensor network, which has several supernodes for data relay and a large number of energy-constrained sensor nodes that are deployed randomly to cover certain targets. Since targets are covered by many sensors, we create several cover sets that are active successively to save power. We introduce the Heterogeneous Connected Set Covers (HCSC) which aims to find at least one cover set that covers all the targets and is connected to a data-relaying supernode. A sensor node can participate in different set covers but the sum of energy spent in all sets is constrained by the initial energy resources of that sensor node. This is the first solution proposed for the target coverage in heterogeneous wireless sensor networks. We show that the HCSC is an NP-Complete problem and propose three distributed algorithms for it and showing simulation results to verify the proposed approaches.
Show less - Date Issued
- 2006
- PURL
- http://purl.flvc.org/fcla/dt/13342
- Subject Headings
- Wireless communication systems, Sensor networks, Wireless LANs
- Format
- Document (PDF)
- Title
- Enhanced ticket-based QoS routing protocols in ad hoc networks.
- Creator
- Huang, Chun-Jung, Florida Atlantic University, Wu, Jie
- Abstract/Description
-
This thesis describes QoS routing techniques in ad hoc networks. QoS routing is to find paths between given source and destinations that fulfill a set of QoS requirements. QoS routing in ad hoc networks is a challenging problem due to the dynamical nature of ad hoc networks and the complexity of the QoS routing problem. Ticket-based probing scheme (TBP) is a creative approach to solve QoS routing problem, however, its proactive nature makes it deficient and unscalable. In this thesis, we...
Show moreThis thesis describes QoS routing techniques in ad hoc networks. QoS routing is to find paths between given source and destinations that fulfill a set of QoS requirements. QoS routing in ad hoc networks is a challenging problem due to the dynamical nature of ad hoc networks and the complexity of the QoS routing problem. Ticket-based probing scheme (TBP) is a creative approach to solve QoS routing problem, however, its proactive nature makes it deficient and unscalable. In this thesis, we first present the adaptive ticket-based routing protocol (ATBR), a proactive protocol enhanced from TBP, by introducing a new imprecise QoS state model. We then present the location-aided, ticket-based routing protocol (LTBR), an integration of locate-based routing and ticket-based routing, where tickets are dynamically generated and guided by location and QoS metric. Our simulations show that, in networks under any density, LTBR achieves close performances to flooding with considerably lower routing overhead.
Show less - Date Issued
- 2003
- PURL
- http://purl.flvc.org/fcla/dt/13060, http://purl.flvc.org/fau/fd/FADT13060
- Subject Headings
- Computer network protocols, Mobile computing, Wireless communication systems, Routers (Computer networks)
- Format
- Document (PDF)
- Title
- Exploring the electromagnetics of millimeter-wave through terahertz spectrum: de novo studies vis-à-vis materials science, biomedical applications and wireless communication.
- Creator
- Sharma, Bharti, Neelakanta, Perambur S., Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
The present research is a targeted endeavor to study the underlying characteristics and novel applications of millimeter (mm) wave through terahertz (THz) spectrum of electromagnetic (EM) energy. Focused thereof are the following specific tasks broadly considered pertinent to the said EM spectral range: (i) To elucidate the material characteristics vis-à-vis the interaction with EM energy at the test frequencies; (ii) to identify biomedical applications based on the material characteristics...
Show moreThe present research is a targeted endeavor to study the underlying characteristics and novel applications of millimeter (mm) wave through terahertz (THz) spectrum of electromagnetic (EM) energy. Focused thereof are the following specific tasks broadly considered pertinent to the said EM spectral range: (i) To elucidate the material characteristics vis-à-vis the interaction with EM energy at the test frequencies; (ii) to identify biomedical applications based on the material characteristics studied and applied to biomedia; and (iii) to model the wireless communication channels supporting EM waves at the test frequency bands of interest. Commensurate with the scope as above, the objectives of the research are as follows:
Show less - Date Issued
- 2014
- PURL
- http://purl.flvc.org/fau/fd/FA00004330, http://purl.flvc.org/fau/fd/FA00004330
- Subject Headings
- Electromagnetic waves -- Scattering, Pattern recognition systems, Scattering (Physics), Terahertz technology, Wireless communication systems
- Format
- Document (PDF)
- Title
- Impact of interference on connectivity and outage performances in wireless communication networks: interference-based channel models.
- Creator
- Mukasa, Constantine, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
In recent years, a plethora of wireless applications such as Bluetooth and Ultra-wide band (UWB) radio have emerged. This drastic increase has overly congested the spectrum. So, new networks such as cognitive radios that can solve the spectrum congestion have emerged. But in such networks, interference is introduced at the physical layer. We study and develop an interference model capable of capturing the intrinsic characteristics of the coexistence of such wireless applications. We...
Show moreIn recent years, a plethora of wireless applications such as Bluetooth and Ultra-wide band (UWB) radio have emerged. This drastic increase has overly congested the spectrum. So, new networks such as cognitive radios that can solve the spectrum congestion have emerged. But in such networks, interference is introduced at the physical layer. We study and develop an interference model capable of capturing the intrinsic characteristics of the coexistence of such wireless applications. We investigate the effect of interference using device isolation probability or outage probability in presence Rayleigh and Nakagami-m fading at the physical layer and the impact of lognormal shadowing. We assume that the devices are either deterministically placed or randomly distributed according to a Poisson point process. We derive explicit expressions for the isolation probability and outage probability that give insight into how these channel impairments affect communication in these applications. We use computer simulations to validate our analytical results.
Show less - Date Issued
- 2013
- PURL
- http://purl.flvc.org/fcla/dt/3362551
- Subject Headings
- Wireless communication systems, Technological innovations, Wireless communication systems, Mathematical models, Orthogonal frequency division multiplexing
- Format
- Document (PDF)
- Title
- Implementation of a mobile data collector in wireless sensor networks for energy conservation.
- Creator
- Heshike, Pedro L., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
A Wireless Sensor Network (WSN) is composed of low-cost electronic devices with sensing, data storage and transmitting capabilities, powered by batteries. There are extensive studies in the field of WSN investigating different algorithms and protocols for data collection. A data collector can be static or mobile. Using a mobile data collector can extend network lifetime and can be used to collect sensor data in hardly accessible locations, partitioned networks, and delay-tolerant networks....
Show moreA Wireless Sensor Network (WSN) is composed of low-cost electronic devices with sensing, data storage and transmitting capabilities, powered by batteries. There are extensive studies in the field of WSN investigating different algorithms and protocols for data collection. A data collector can be static or mobile. Using a mobile data collector can extend network lifetime and can be used to collect sensor data in hardly accessible locations, partitioned networks, and delay-tolerant networks. The implementation of the mobile data collector in our study consists of combining two different platforms: the Crossbow sensor hardware and the NXT Legos. We developed an application for data collection and sensor querying support. Another important contribution is designing a semi-autonomous robot control. This hardware prototype implementation shows the benefits of using a mobile data collector in WSN. It also serves as a reference in developing future applications for mobile WSNs.
Show less - Date Issued
- 2011
- PURL
- http://purl.flvc.org/FAU/3171401
- Subject Headings
- Wireless communication systems, Technological innovations, Sensor networks, Design and construction, Compter network protocols, Ad hoc networks (Computer networks), Technological innovations
- Format
- Document (PDF)
- Title
- Implementation of the Sensor-MAC protocol for the JiST/SWANS simulator.
- Creator
- Tippanagoudar, Veerendra., Florida Atlantic University, Mahgoub, Imad, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
In recent years, advances in wireless technologies have enabled novel applications for wireless devices. Sensor network is one such application that consists of large number of battery-operated nodes. To simulate such networks with large number of nodes, a wireless sensor network simulator that is highly scalable is vital. JiST/SWANS is one such simulator that is highly scalable. However, the JiST/SWANS MAC layer implementation of 802.11b is not suitable for sensor networks, which are energy...
Show moreIn recent years, advances in wireless technologies have enabled novel applications for wireless devices. Sensor network is one such application that consists of large number of battery-operated nodes. To simulate such networks with large number of nodes, a wireless sensor network simulator that is highly scalable is vital. JiST/SWANS is one such simulator that is highly scalable. However, the JiST/SWANS MAC layer implementation of 802.11b is not suitable for sensor networks, which are energy-constrained. Hence, our main focus is to implement the S-MAC protocol in JiST/SWANS. The S-MAC protocol allows the nodes to go to sleep and thereby it helps conserve energy. This subsequently helps the nodes to extend their effective lifetime. We validate our S-MAC protocol implementation in the JiST/SWANS through simulations.
Show less - Date Issued
- 2006
- PURL
- http://purl.flvc.org/fcla/dt/13396
- Subject Headings
- Wireless communication systems, Sensor networks, Wireless LANs
- Format
- Document (PDF)
- Title
- Indexed resource auction multiple access (I-RAMA): A new medium access scheme for third generation wireless networks.
- Creator
- Barrantes-Sliesarieva, Elena Gabriela., Florida Atlantic University, Ulyas, Mohammad
- Abstract/Description
-
Indexed Resource Auction Multiple Access (I-RAMA), a new medium access protocol for wireless cellular networks based on Resource Auction Multiple Access (RAMA) is presented. I-RAMA relies in variable length resource auctions, whose length depends on the time it takes the Base Station to uniquely identify the Mobile Station. This identification is done by using dynamic Base Station information about the users present in the cell at any moment. I-RAMA effectively reduces the amount of time...
Show moreIndexed Resource Auction Multiple Access (I-RAMA), a new medium access protocol for wireless cellular networks based on Resource Auction Multiple Access (RAMA) is presented. I-RAMA relies in variable length resource auctions, whose length depends on the time it takes the Base Station to uniquely identify the Mobile Station. This identification is done by using dynamic Base Station information about the users present in the cell at any moment. I-RAMA effectively reduces the amount of time spent in the resource auctions without introducing contention or excessive complexity at the Base Station. The effects of introducing data users in the system are investigated using a simulation, and it is shown that I-RAMA guarantees Quality of Service for isochronous users while maintaining a bounded delay for data users at much higher loads than RAMA.
Show less - Date Issued
- 1995
- PURL
- http://purl.flvc.org/fcla/dt/15204
- Subject Headings
- Wireless communication systems, Cellular radio, Mobile communication systems, Computer algorithms
- Format
- Document (PDF)