Current Search: Wireless communication systems -- Technological innovations (x)
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- Title
- Application of video error resilience techniques for mobile broadcast multicast services (MBMS).
- Creator
- Furht, Borko, Praveenkumar, Sanigepalli, Kalva, Hari
- Abstract/Description
-
With data throughput for mobile devices constantly increasing, services such as video broadcast and multicast are becoming feasible. The 3GPP (3rd Generation Partnership Project) committee is currently working on a standard for mobile broadcast and multicast services (MBMS). MBMS is expected to enable easier deployment of video and multimedia services on 3G networks. We present an overview of the standard including the proposed architecture and requirements focusing on radio aspects. We...
Show moreWith data throughput for mobile devices constantly increasing, services such as video broadcast and multicast are becoming feasible. The 3GPP (3rd Generation Partnership Project) committee is currently working on a standard for mobile broadcast and multicast services (MBMS). MBMS is expected to enable easier deployment of video and multimedia services on 3G networks. We present an overview of the standard including the proposed architecture and requirements focusing on radio aspects. We discuss the issue of video error resilience in such services that is critical to maintain consistent quality for terminals. The error resilience techniques currently used in video streamingservices are not suitable for MBMS services. We analyze the error resilience techniques that are applicable within the context of MBMS standard and present our early research in this area.
Show less - Date Issued
- 2004-12-13 - 2004-12-15
- PURL
- http://purl.flvc.org/fcla/dt/347823
- Subject Headings
- Multimedia systems., Broadcasting --Technological innovations., Wireless communication systems., Multimedia communications.
- 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
- Adaptive hierarchical weighted fair queuing scheduling in WiMAX networks.
- Creator
- AL-Ghanem, Waleed Khalid, Ilyas, Mohammad, Mahgoub, Imad, Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
The growing demand for faster connection to the Internet service and wireless multimedia applications has motivated the development of broadband wireless access technologies in recent years. WiMAX has enabled convergence of mobile and fixed broadband networks through a common wide-area radio-access technology and flexible network architecture. Scheduling is a fundamental component in resource management in WiMAX networks and plays the main role in meeting QoS requirements such as delay,...
Show moreThe growing demand for faster connection to the Internet service and wireless multimedia applications has motivated the development of broadband wireless access technologies in recent years. WiMAX has enabled convergence of mobile and fixed broadband networks through a common wide-area radio-access technology and flexible network architecture. Scheduling is a fundamental component in resource management in WiMAX networks and plays the main role in meeting QoS requirements such as delay, throughput and packet loss for different classes of service. In this dissertation work, the performance of uplink schedulers at the fixed WiMAX MAC layer has been considered, we proposed an Adaptive Hierarchical Weighted Fair Queuing Scheduling algorithm, the new scheduling algorithm adapts to changes in traffic, at the same time; it is able to heuristically enhance the performance of WiMAX network under most circumstances. The heuristic nature of this scheduling algorithm enables the MAC layer to meet the QoS requirements of the users. The performance of this adaptive WiMAX Uplink algorithm has been evaluated by simulation using MATLAB. Results indicate that the algorithm is efficient in scheduling the Base Stations’ traffic loads, and improves QoS. The utilization of relay stations is studied and simulation results are compared with the case without using relay stations. The results show that the proposed scheduling algorithm improves Quality of Service of WiMAX system.
Show less - Date Issued
- 2014
- PURL
- http://purl.flvc.org/fau/fd/FA00004178, http://purl.flvc.org/fau/fd/FA00004178
- Subject Headings
- Computer networks -- Technological innovations, Optical fiber communication, Wireless communication systems -- Technological innovations, Wireless metropolitan area networks -- Security measures
- Format
- Document (PDF)
- Title
- Cross-domain authentication for multi-protocol phones.
- Creator
- Thakker, Chetan., Florida Atlantic University, Pandya, Abhijit S., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
The last decade has seen a surge in demand for cellular and WLAN networks. With the introduction of Voice Over IP, cellular companies are looking at WLAN-Cellular integrated networks that shall provide users with economical voice and data services. These networks shall be complimentary to the existing cellular networks. A lot of money is spent in registering and authenticating new users, since they are separately authenticated and registered on the WLAN and Cellular domains. This leads to...
Show moreThe last decade has seen a surge in demand for cellular and WLAN networks. With the introduction of Voice Over IP, cellular companies are looking at WLAN-Cellular integrated networks that shall provide users with economical voice and data services. These networks shall be complimentary to the existing cellular networks. A lot of money is spent in registering and authenticating new users, since they are separately authenticated and registered on the WLAN and Cellular domains. This leads to extra costs for the company. Thus for the integrated networks to have an impact on the market some issues such as simpler authentication and registration must be resolved. Therefore we propose a new inter-working model that shall addresses the authentication and registration problem for an integrated network for voice and data. The Single authentication system of the new inter-working model, shall authenticate the user in an integrated network using the SIM credentials, this authentication shall be valid for both voice and data. Also registration costs will be saved by preventing separate registration of users in the WLAN and Cellular domain.
Show less - Date Issued
- 2005
- PURL
- http://purl.flvc.org/fcla/dt/13260
- Subject Headings
- Integrated services digital networks, Digital telephone systems, Wireless communication systems--Technological innovations, Mobile communication systems--Technological innovations
- Format
- Document (PDF)
- Title
- Key management in mobile ad hoc networks.
- Creator
- Wu, Bing., Florida Atlantic University, Wu, Jie, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
In mobile ad hoc networks (MANETs), providing secure communications is a big challenge due to unreliable wireless media, host mobility and lack of infrastructure. Usually, cryptographic techniques are used for secure communications in wired networks. Symmetric and asymmetric cryptography have their advantages and disadvantages. In fact, any cryptographic means is ineffective if its key management is weak. Key management is also a central aspect for security in mobile ad hoc networks. In...
Show moreIn mobile ad hoc networks (MANETs), providing secure communications is a big challenge due to unreliable wireless media, host mobility and lack of infrastructure. Usually, cryptographic techniques are used for secure communications in wired networks. Symmetric and asymmetric cryptography have their advantages and disadvantages. In fact, any cryptographic means is ineffective if its key management is weak. Key management is also a central aspect for security in mobile ad hoc networks. In MANETs, the computational load and complexity for key management are strongly subject to restriction by the node's available resources and the dynamic nature of network topology. We proposed a secure and efficient key management framework (SEKM) for MANETs. SEKM builds a PKI by applying a secret sharing scheme and using an underlying multicast server groups. In SEKM, each server group creates a view of the certificate authority (CA) and provides certificate update service for all nodes, including the servers themselves. Motivated by the distributed key management service, we introduced k-Anycast concept and proposed three k-anycast routing schemes for MANETs. k-anycast is proposed to deliver a packet to any threshold k members of a set of hosts. Our goal is to reduce the routing control messages and network delay to reach any k servers. The first scheme is called controlled flooding. The second scheme, called component-based scheme I, is to form multiple components such that each component has at least k members. The third scheme, called component-based scheme II, in which the membership a component maintains is relaxed to be less than k. Collaborative and group-oriented applications in MANETs is an active research area. Group key management is a central building block in securing group communications in MANETs. However, group key management for large and dynamic groups in MANETs is a difficult problem. We propose a simple and efficient group key management scheme that we named SEGK for MANETs, which is based on n-party Diffie-Hellman (DH). The basic idea of our scheme is that a physical multicast tree is formed in MANETs for efficiency. To achieve fault tolerance, double multicast trees are constructed and maintained. A group coordinator computes and distributes intermediate keying materials to all members through multicast tree links. All group members take turns acting as group coordinator and distributing the workload of group rekeying during any change of group membership. Every group member computes the group key in a distributed manner.
Show less - Date Issued
- 2006
- PURL
- http://purl.flvc.org/fcla/dt/12234
- Subject Headings
- Electronic commerce--Technological innovations, Mobile commerce--Technological innovations, Wireless communication systems--Management, Mobile communication systems--Management
- Format
- Document (PDF)
- Title
- A Phased Approach to Evaluate the Performance of Handoff by Mobile Handsets.
- Creator
- Siddiqui, Arjumand Fatima, Pandya, Abhijit S., Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
The ever increasing demand for capacity in wireless cellular networks is resolved by decreasing the size of the cells. The smaller cells created inside large cells are called microcells and they cover smaller and dense areas. As a result of this, the mobile device ends up changing the base stations or performing handover at a much higher rate. To maintain the reliability and quality of the call, it is obligatory to ascertain that the handover is performed at a proper location. If the handover...
Show moreThe ever increasing demand for capacity in wireless cellular networks is resolved by decreasing the size of the cells. The smaller cells created inside large cells are called microcells and they cover smaller and dense areas. As a result of this, the mobile device ends up changing the base stations or performing handover at a much higher rate. To maintain the reliability and quality of the call, it is obligatory to ascertain that the handover is performed at a proper location. If the handover is delayed or the mobile handset drags its base station, it is more probable that either the call will drop or the quality of the call will be compromised. The last thing a mobile handset user would want is to experience any of these two consequences. In this thesis we study the methods to analyze the performance ofhandover by the mobile handsets in the drive setup under test. This thesis presents a model for analyzing the performance ofhandoffbased on the measurements ofthe received signal strength indicator and the color code recorded by the mobile handset in the drive test field path. The model from the simulations is seen to yield results that agree with other research about the performance of mobile handsets.
Show less - Date Issued
- 2007
- PURL
- http://purl.flvc.org/fau/fd/FA00012551
- Subject Headings
- Mobile communication systems--Design, Wireless communication systems--Technological innovations, Cellular telephones--Design
- Format
- Document (PDF)
- Title
- Studies on performance aspects of smart wireless devices and related network services.
- Creator
- Noori, Aziz Ulhaq, Neelakanta, Perambur S., Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
This study is a focused effort on elucidating the performance aspects of modern, handheld wireless devices and associated mobile network services. Specifically addressed thereof are: (i) Assessing the performance details on certain hardware sections of smart handheld devices and (ii) determining the performance profile of market penetration considerations vis-à-vis provisioning mobile networks. To meet the scope of this research, the projected efforts are exercised in compiling relevant...
Show moreThis study is a focused effort on elucidating the performance aspects of modern, handheld wireless devices and associated mobile network services. Specifically addressed thereof are: (i) Assessing the performance details on certain hardware sections of smart handheld devices and (ii) determining the performance profile of market penetration considerations vis-à-vis provisioning mobile networks. To meet the scope of this research, the projected efforts are exercised in compiling relevant literature and deciding the said hardware and technoeconomic performance issues. Hence, written in two parts, Part A is devoted to hardware performance details of smart, handheld devices relevant to (a) delay issues in PCB layouts; (b) crosstalk problems at the baseband level (audio/multimedia) using EMI concepts and (c) ascertaining non-catastrophic EMP/EMI effects at the RF-sections so as to implement protection strategies via compensating networks. Part B is concerned with the technoeconomics of wireless networks in supporting mobile (handheld devices). Correspondingly, two market related considerations versus service performance details are considered. The first one refers to deducing a relative performance index that includes technology (mobile speed) details plus economics profiles of the users in the service area. The second task refers to elucidating a performance index of such services in terms of hedonic pricing heuristics. The theoretical aspects of the test studies as above are supplemented with experimental and/or simulation details as appropriate. Hence, the efficacy of performance details are discussed in real-world applications. Lastly, possible research items for future studies are identified as open-questions.
Show less - Date Issued
- 2015
- PURL
- http://purl.flvc.org/fau/fd/FA00004395, http://purl.flvc.org/fau/fd/FA00004395
- Subject Headings
- Mobile communication systems -- Standards, Network performance (Telecommunications), Smartphones, Technoeconomcs, Wireless communication systems -- Technological innovations
- Format
- Document (PDF)
- Title
- Knowledge Discovery Through Drive Test Data Visualization.
- Creator
- Saxena, Shalini, Pandya, Abhijit S., Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
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With the increasing number of cellular phone service subscribers, the telecommunications service providers have placed immense emphasis on improving audio quality and ensure fewer dropped calls. Handoff behavior of all handsets is an important factor in quality of service of a mobile phone service. This thesis focuses on the analysis of large volumes of diagnostic data collected from mobile phones in the real world and the identification of aberrant behavior of a mobile handset under test by...
Show moreWith the increasing number of cellular phone service subscribers, the telecommunications service providers have placed immense emphasis on improving audio quality and ensure fewer dropped calls. Handoff behavior of all handsets is an important factor in quality of service of a mobile phone service. This thesis focuses on the analysis of large volumes of diagnostic data collected from mobile phones in the real world and the identification of aberrant behavior of a mobile handset under test by means of drive test data visualization. Our target was to identify poor mobility decisions that are made by the handsets in calls. Premature, delayed or exceedingly sensitive decisions are considered poor mobility decisions. The goal was to compare a set of behaviors from a baseline unit (one accepted to generally operate well). We were able to identify a particular call that was exhibiting a different path (talking to a different cell than expected or taking longer to move to a new cell). We designed a chi-square statistical test to evaluate the performance of specific mobile handset models. We also developed a mobility tool that evaluated the handset's performance by means of mapping the handoffs on the Google Maps. The mapping of the handoffs by means of the Google Maps were very powerful in identifying the above mentioned mobility patterns.
Show less - Date Issued
- 2007
- PURL
- http://purl.flvc.org/fau/fd/FA00012548
- Subject Headings
- Mobile communication systems--Quality control, Wireless communication systems--Technological innovations, Cellular telephones--Design
- Format
- Document (PDF)
- Title
- Investigation of debonding failures in sandwich constructions.
- Creator
- Sendlein, Lyle Scott., Florida Atlantic University, Merry, Stephanie L., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
Debonding failure of cored marine composite materials is investigated. A new test method that subjects the bond line between the core and the face sheets to a shear stress singularity is presented and studied analytically by laminated beam shear deformation theory, numerically by the finite element method, and experimentally with specimens of glass/polyester face sheets on balsa wood or PVC core sandwich beams.
- Date Issued
- 1989
- PURL
- http://purl.flvc.org/fcla/dt/14519
- Subject Headings
- Mobile communication systems--Design, Wireless communication systems--Technological innovations, Cellular telephones--Design
- Format
- Document (PDF)
- Title
- Mechanisms for prolonging network lifetime in wireless sensor networks.
- Creator
- Yang, Yinying., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Sensors are used to monitor and control the physical environment. A Wireless Sen- sor Network (WSN) is composed of a large number of sensor nodes that are densely deployed either inside the phenomenon or very close to it [18][5]. Sensor nodes measure various parameters of the environment and transmit data collected to one or more sinks, using hop-by-hop communication. Once a sink receives sensed data, it processes and forwards it to the users. Sensors are usually battery powered and it is...
Show moreSensors are used to monitor and control the physical environment. A Wireless Sen- sor Network (WSN) is composed of a large number of sensor nodes that are densely deployed either inside the phenomenon or very close to it [18][5]. Sensor nodes measure various parameters of the environment and transmit data collected to one or more sinks, using hop-by-hop communication. Once a sink receives sensed data, it processes and forwards it to the users. Sensors are usually battery powered and it is hard to recharge them. It will take a limited time before they deplete their energy and become unfunctional. Optimizing energy consumption to prolong network lifetime is an important issue in wireless sensor networks. In mobile sensor networks, sensors can self-propel via springs [14], wheels [20], or they can be attached to transporters, such as robots [20] and vehicles [36]. In static sensor networks with uniform deployment (uniform density), sensors closest to the sink will die first, which will cause uneven energy consumption and limitation of network life- time. In the dissertation, the nonuniform density is studied and analyzed so that the energy consumption within the monitored area is balanced and the network lifetime is prolonged. Several mechanisms are proposed to relocate the sensors after the initial deployment to achieve the desired density while minimizing the total moving cost. Using mobile relays for data gathering is another energy efficient approach. Mobile sensors can be used as ferries, which carry data to the sink for static sensors so that expensive multi-hop communication and long distance communication are reduced. In this thesis, we propose a mobile relay based routing protocol that considers both energy efficiency and data delivery delay. It can be applied to both event-based reporting and periodical report applications., Another mechanism used to prolong network lifetime is sensor scheduling. One of the major components that consume energy is the radio. One method to conserve energy is to put sensors to sleep mode when they are not actively participating in sensing or data relaying. This dissertation studies sensor scheduling mechanisms for composite event detection. It chooses a set of active sensors to perform sensing and data relaying, and all other sensors go to sleep to save energy. After some time, another set of active sensors is chosen. Thus sensors work alternatively to prolong network lifetime.
Show less - Date Issued
- 2010
- PURL
- http://purl.flvc.org/FAU/1870693
- Subject Headings
- Wireless communication systems, Technological innovations, Wireless communication systems, Design and construction, Ad hoc networks (Computer networks), Technological innovations, Sensor networks, Design and construction, Computer algorithms, Computer network protocols
- Format
- Document (PDF)
- Title
- Resilient system design and efficient link management for the wireless communication of an ocean current turbine test bed.
- Creator
- Marcus, Anthony M., Cardei, Ionut E., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
To ensure that a system is robust and will continue operation even when facing disruptive or traumatic events, we have created a methodology for system architects and designers which may be used to locate risks and hazards in a design and enable the development of more robust and resilient system architectures. It uncovers design vulnerabilities by conducting a complete exploration of a systems’ component operational state space by observing the system from multi-dimensional perspectives and...
Show moreTo ensure that a system is robust and will continue operation even when facing disruptive or traumatic events, we have created a methodology for system architects and designers which may be used to locate risks and hazards in a design and enable the development of more robust and resilient system architectures. It uncovers design vulnerabilities by conducting a complete exploration of a systems’ component operational state space by observing the system from multi-dimensional perspectives and conducts a quantitative design space analysis by means of probabilistic risk assessment using Bayesian Networks. Furthermore, we developed a tool which automated this methodology and demonstrated its use in an assessment of the OCTT PHM communication system architecture. To boost the robustness of a wireless communication system and efficiently allocate bandwidth, manage throughput, and ensure quality of service on a wireless link, we created a wireless link management architecture which applies sensor fusion to gather and store platform networked sensor metrics, uses time series forecasting to predict the platform position, and manages data transmission for the links (class based, packet scheduling and capacity allocation). To validate our architecture, we developed a link management tool capable of forecasting the link quality and uses cross-layer scheduling and allocation to modify capacity allocation at the IP layer for various packet flows (HTTP, SSH, RTP) and prevent congestion and priority inversion. Wireless sensor networks (WSN) are vulnerable to a plethora of different fault types and external attacks after their deployment. To maintain trust in these systems and increase WSN reliability in various scenarios, we developed a framework for node fault detection and prediction in WSNs. Individual wireless sensor nodes sense characteristics of an object or environment. After a smart device successfully connects to a WSN’s base station, these sensed metrics are gathered, sent to and stored on the device from each node in the network, in real time. The framework issues alerts identifying nodes which are classified as faulty and when specific sensors exceed a percentage of a threshold (normal range), it is capable of discerning between faulty sensor hardware and anomalous sensed conditions. Furthermore we developed two proof of concept, prototype applications based on this framework.
Show less - Date Issued
- 2013
- PURL
- http://purl.flvc.org/fau/fd/FA0004035
- Subject Headings
- Fault tolerance (Engineering), Reliability (Engineering), Sensor networks -- Security measures, Systems engineering, Wireless communication systems -- Technological innovations
- 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
- 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
- Probabilistic predictor-based routing in disruption-tolerant networks.
- Creator
- Yuan, Quan., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Disruption-Tolerant Networks (DTNs) are the networks comprised of a set of wireless nodes, and they experience unstable connectivity and frequent connection disruption because of the limitations of radio range, power, network density, device failure, and noise. DTNs are characterized by their lack of infrastructure, device limitation, and intermittent connectivity. Such characteristics make conventional wireless network routing protocols fail, as they are designed with the assumption the...
Show moreDisruption-Tolerant Networks (DTNs) are the networks comprised of a set of wireless nodes, and they experience unstable connectivity and frequent connection disruption because of the limitations of radio range, power, network density, device failure, and noise. DTNs are characterized by their lack of infrastructure, device limitation, and intermittent connectivity. Such characteristics make conventional wireless network routing protocols fail, as they are designed with the assumption the network stays connected. Thus, routing in DTNs becomes a challenging problem, due to the temporal scheduling element in a dynamic topology. One of the solutions is prediction-based, where nodes mobility is estimated with a history of observations. Then, the decision of forwarding messages during data delivery can be made with that predicted information. Current prediction-based routing protocols can be divided into two sub-categories in terms of that whether they are probability related: probabilistic and non-probabilistic. This dissertation focuses on the probabilistic prediction-based (PPB) routing schemes in DTNs. We find that most of these protocols are designed for a specified topology or scenario. So almost every protocol has some drawbacks when applied to a different scenario. Because every scenario has its own particular features, there could hardly exist a universal protocol which can suit all of the DTN scenarios. Based on the above motivation, we investigate and divide the current DTNs scenarios into three categories: Voronoi-based, landmark-based, and random moving DTNs. For each category, we design and implement a corresponding PPB routing protocol for either basic routing or a specified application with considering its unique features., Specifically, we introduce a Predict and Relay routing protocol for Voronoi-based DTNs, present a single-copy and a multi-copy PPB routing protocol for landmark-based DTNs, and propose DRIP, a dynamic Voronoi region-based publish/subscribe protocol, to adapt publish/subscribe systems to random moving DTNs. New concepts, approaches, and algorithms are introduced during our work.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/359928
- Subject Headings
- Routers (Computer networks), Computer network protocols, Computer networks, Reliability, Computer algorithms, Wireless communication systems, Technological innovations
- 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
-
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)
- Title
- Mechanisms for improving energy efficiency in wireless sensor networks.
- Creator
- Fonoage, Mirela Ioana., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
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A Wireless Sensor Network (WSN) is composed of a large number of sensor nodes that are densely deployed in an area. One of the main issues addressed in WSNs research is energy efficiency due to sensors' limited energy resources. WSNs are deployed to monitor and control the physical environment, and to transmit the collected data to one or more sinks using multi-hop communication. Energy efficiency protocols represent a key mechanism in WSNs. This dissertation proposes several methods used to...
Show moreA Wireless Sensor Network (WSN) is composed of a large number of sensor nodes that are densely deployed in an area. One of the main issues addressed in WSNs research is energy efficiency due to sensors' limited energy resources. WSNs are deployed to monitor and control the physical environment, and to transmit the collected data to one or more sinks using multi-hop communication. Energy efficiency protocols represent a key mechanism in WSNs. This dissertation proposes several methods used to prolong WSNs lifetime focusing on designing energy efficient communication protocols. A critical issue for data gathering in WSNs is the formation of energy holes near the sinks where sensor nodes participate more in relaying data on behalf of other sensors. The solution proposed in this dissertation is to use mobile sinks that change their location to overcome the formation of energy holes. First, a study of the improvement in network lifetime when sinks move along the perimeter of a hexagonal tiling is conveyed. Second, a design of a distributed and localized algorithm used by sinks to decide their next move is proposed. Two extensions of the distributed algorithm, coverage and time-delivery requirement, are also addressed. Sensor scheduling mechanisms are used to increase network lifetime by sending redundant sensor nodes to sleep. In this dissertation a localized connected dominating set based approach is used to optimize network lifetime of a composite event detection application. A set of active nodes form a connected set that monitor the environment and send data to sinks. After some time, a new active nodes set is chosen. Thus, network lifetime is prolonged by alternating the active sensors. QoS is another main issue encountered in WSNs because of the dynamically changing network topology., This dissertation introduces an energy efficient QoS based routing for periodic and event-based reporting applications. A geographic routing mechanism combined with QoS support is used to forward packets in the network. Congestion control is achieved by using a ring or barrier mechanism that captures and aggregates messages that report the same event to the same sink. The main operations of the barrier mechanism are presented in this dissertation.
Show less - Date Issued
- 2010
- PURL
- http://purl.flvc.org/FAU/2975242
- Subject Headings
- Computer network protocols, Wireless communication systems, Technological innovations, Sensor networks, Design and construction
- Format
- Document (PDF)
- Title
- Patterns for wireless sensor networks.
- Creator
- Sahu, Anupama., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
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Sensors are shaping many activities in our society with an endless array of potential applications in military, civilian, and medical application. They support different real world applications ranging from common household appliances to complex systems. Technological advancement has enabled sensors to be used in medical applications, wherein they are deployed to monitor patients and assist disabled patients. Sensors have been invaluable in saving lives, be it a soldier's life in a remote...
Show moreSensors are shaping many activities in our society with an endless array of potential applications in military, civilian, and medical application. They support different real world applications ranging from common household appliances to complex systems. Technological advancement has enabled sensors to be used in medical applications, wherein they are deployed to monitor patients and assist disabled patients. Sensors have been invaluable in saving lives, be it a soldier's life in a remote battlefield or a civilian's life in a disaster area or natural calamities. In every application the sensors are deployed in a pre-defined manner to perform a specific function. Understanding the basic structure of a sensor node is essential as this would be helpful in using the sensors in devices and environments that have not been explored. In this research, patterns are used to present a more abstract view of the structure and architecture of sensor nodes and wireless sensor networks. This would help an application designer to choose from different types of sensor nodes and sensor network architectures for applications such as robotic landmine detection or remote patient monitoring systems. Moreover, it would also help the network designer to reuse, combine or modify the architectures to suit more complex needs. More importantly, they can be integrated with complete IT applications. One of the important applications of wireless sensor networks in the medical field is a remote patient monitoring system. In this work, patterns were developed to describe the architecture of patient monitoring system., This pattern describes how to connect sensor nodes and other wireless devices with each other to form a network that aims to monitor the vital signs of a person and report it to a central system. This central system could be accessed by the patient's healthcare provider for treatment purposes. This system shows one of the most important applications of sensors and it application which needs to be integrated with medical records and the use of patterns makes this integration much simpler.
Show less - Date Issued
- 2010
- PURL
- http://purl.flvc.org/FAU/2979380
- Subject Headings
- Wireless communication systems, Technological innovations, Wireless sensor networks, Design and construction, Computer network protocols, Multisensensor data fusion
- 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
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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
- Implementations Of The DTM, DADCQ And SLAB VANET Broadcast Protocols For The Ns-3 Simulator.
- Creator
- Alwakeel, Ahmed M., Mahgoub, Imad, Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
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This work presents the implementations of three adaptive broadcast protocols for vehicular ad hoc networks (VANET) using the Network Simulator 3 (Ns-3). Performing real life tests for VANET protocols is very costly and risky, so simulation becomes a viable alternative technique. Ns-3 is one of the most advanced open source network simulators. Yet Ns-3 lacks implementations of broadcast protocols for VANET. We first implement the Distance to Mean (DTM) protocol, which uses the distance to mean...
Show moreThis work presents the implementations of three adaptive broadcast protocols for vehicular ad hoc networks (VANET) using the Network Simulator 3 (Ns-3). Performing real life tests for VANET protocols is very costly and risky, so simulation becomes a viable alternative technique. Ns-3 is one of the most advanced open source network simulators. Yet Ns-3 lacks implementations of broadcast protocols for VANET. We first implement the Distance to Mean (DTM) protocol, which uses the distance to mean to determine if a node should rebroadcast or not. We then implement the Distribution-Adaptive Distance with Channel Quality (DADCQ) protocol, which uses node distribution, channel quality and distance to determine if a node should favor rebroadcasting. The third protocol, Statistical Location-Assisted Broadcast protocol (SLAB), is an improvement of DADCQ which automates the threshold function design using machine learning. Our NS-3 implementations of the three protocols have been validated against their JiST/SWANS implementations.
Show less - Date Issued
- 2016
- PURL
- http://purl.flvc.org/fau/fd/FA00004565, http://purl.flvc.org/fau/fd/FA00004565
- Subject Headings
- Vehicular ad hoc networks (Computer networks)--Technological innovations., Wireless communication systems--Technological innovations., Mobile communication systems--Technological innovations., Mobile computing., Intelligent transportation systems--Mathematical models., Routing protocols (Computer network protocols)
- Format
- Document (PDF)
- Title
- 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
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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)