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- Title
- Context-aware hybrid data dissemination in vehicular networks.
- Creator
- Rathod, Monika M., Mahgoub, Imad, Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
This work presents the development of the Context-Aware Hybrid Data Dissemination protocol for vehicular networks. The importance of developing vehicular networking data dissemination protocols is exemplified by the recent announcement by the U.S. Department of Transportation (DOT) National Highway Traffic Safety Administration (NHTSA) to enable vehicle-to-vehicle (V2V) communication technology. With emphasis on safety, other useful applications of V2V communication include but are not...
Show moreThis work presents the development of the Context-Aware Hybrid Data Dissemination protocol for vehicular networks. The importance of developing vehicular networking data dissemination protocols is exemplified by the recent announcement by the U.S. Department of Transportation (DOT) National Highway Traffic Safety Administration (NHTSA) to enable vehicle-to-vehicle (V2V) communication technology. With emphasis on safety, other useful applications of V2V communication include but are not limited to traffic and routing, weather, construction and road hazard alerts, as well as advertisement and entertainment. The core of V2V communication relies on the efficient dispersion of relevant data through wireless broadcast protocols for these varied applications. The challenges of vehicular networks demand an adaptive broadcast protocol capable of handling diverse applications. This research work illustrates the design of a wireless broadcast protocol that is context-aware and adaptive to vehicular environments taking into consideration vehicle density, road topology, and type of data to be disseminated. The context-aware hybrid data dissemination scheme combines store-and-forward and multi-hop broadcasts, capitalizing on the strengths of both these categories and mitigates the weaknesses to deliver data with maximum efficiency to a widest possible reach. This protocol is designed to work in both urban and highway mobility models. The behavior and performance of the hybrid data dissemination scheme is studied by varying the broadcast zone radius, aggregation ratio, data message size and frequency of the broadcast messages. Optimal parameters are determined and the protocol is then formulated to become adaptive to node density by keeping the field size constant and increasing the number of nodes. Adding message priority levels to propagate safety messages faster and farther than non-safety related messages is the next context we add to our adaptive protocol. We dynamically set the broadcast region to use multi-hop which has lower latency to propagate safety-related messages. Extensive simulation results have been obtained using realistic vehicular network scenarios. Results show that Context-Aware Hybrid Data Dissemination Protocol benefits from the low latency characteristics of multi-hop broadcast and low bandwidth consumption of store-and-forward. The protocol is adaptive to both urban and highway mobility models.
Show less - Date Issued
- 2014
- PURL
- http://purl.flvc.org/fau/fd/FA00004152, http://purl.flvc.org/fau/fd/FA00004152
- Subject Headings
- Context aware computing, Convergence (Telecommunication), Intelligent transportation systems, Internetworking (Telecommunication), Routing (Computer network management), Routing protocols (Computer network protocols), Vehicular ad hoc networks (Computer networks)
- 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
- A utility-based routing scheme in multi-hop wireless networks.
- Creator
- Lu, Mingming., College of Engineering and Computer Science, Florida Atlantic University, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Multi-hop wireless networks are infrastructure-less networks consisting of mobile or stationary wireless devices, which include multi-hop wireless mesh networks and multi-hop wireless sensor networks. These networks are characterized by limited bandwidth and energy resources, unreliable communication, and a lack of central control. These characteristics lead to the research challenges of multi-hop wireless networks. Building up routing schemes with good balance among the routing QoS (such as...
Show moreMulti-hop wireless networks are infrastructure-less networks consisting of mobile or stationary wireless devices, which include multi-hop wireless mesh networks and multi-hop wireless sensor networks. These networks are characterized by limited bandwidth and energy resources, unreliable communication, and a lack of central control. These characteristics lead to the research challenges of multi-hop wireless networks. Building up routing schemes with good balance among the routing QoS (such as reliability, cost, and delay) is a paramount concern to achieve high performance wireless networks. These QoS metrics are internally correlated. Most existing works did not fully utilize this correlation. We design a metric to balance the trade-off between reliability and cost, and build up a framework of utility-based routing model in multi-hop wireless networks. This dissertation focuses on the variations with applications of utility-based routing models, designing new concepts, and developing new algorithms for them. A review of existing routing algorithms and the basic utility-based routing model for multi-hop wireless networks has been provided at the beginning. An efficient algorithm, called MaxUtility, has been proposed for the basic utility-based routing model. MaxUtility is an optimal algorithm that can find the best routing path with the maximum expected utility., Various utility-based routing models are extended to further enhance the routing reliability while reducing the routing overhead. Besides computing the optimal path for a given benefit value and a given source-destination pair, the utility-based routing can be further extended to compute all optimal paths for all possible benefit values and/or all source-destination pairs. Our utility-based routing can also adapt to different applications and various environments. In the self-organized environment, where network users are selfish, we design a truthful routing, where selfish users have to tell the truth in order to maximize their utilities. We apply our utility-based routing scheme to the data-gathering wireless sensor networks, where a routing scheme is required to transmit data sensed by multiple sensor nodes to a common sink node.
Show less - Date Issued
- 2008
- PURL
- http://purl.flvc.org/FAU/77647
- Subject Headings
- Wireless communication systems, Security measures, Computer network protocols, Computer algorithms, Computer networks, Security measures
- Format
- Document (PDF)
- Title
- 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
- Properties of Static and Mobile Unreliable Networks and their effects on Combating Malicious Objects.
- Creator
- Ruocco, John, Wu, Jie, Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Wireless sensor networks or WSNs continually become more common in todays world. They are able to give us a constant view into the world as they gather information and make this information more readily available. The infonnation these networks gather and contain is valuable and protecting it is of great importance. Today more and more devices are becoming wireless and mobile. This is allowing for very diverse networks to be created and they are constantly changing. Nodes in these networks...
Show moreWireless sensor networks or WSNs continually become more common in todays world. They are able to give us a constant view into the world as they gather information and make this information more readily available. The infonnation these networks gather and contain is valuable and protecting it is of great importance. Today more and more devices are becoming wireless and mobile. This is allowing for very diverse networks to be created and they are constantly changing. Nodes in these networks are either moving to different positions or going offi ine which constantly changes the overall layout of the network. With this increasing connectivity of today's devices this opens the door for possibility for these types of networks to become targets by malicious objects designed to bring harm to the network. Many unre liable networks already face many problems such as having to optimize battety life and being deployed in areas where they can be damaged. A malicious object in this type of network has the power to destroy data and deplete the networks limited resources such as bandwidth and power. Removal of these malicious objects can also have a negative effect on these limited resources. We must find a way to remove these malicious objects in a way that minimizes loss to the network. In this paper we will look at the information survival threshold of these types of networks. Certain controllable parameters exist that directly impact the survival rate of all data in the network. We will combine this with the addition our own self-replicating objects to the network designed to neutralize their malicious counterparts. We will examine these information survival threshold parameters along with specific parameters available to the network. We shall see how these parameters affect overall survival of data in the network and their impact on our own good data.
Show less - Date Issued
- 2008
- PURL
- http://purl.flvc.org/fau/fd/FA00012545
- Subject Headings
- Wireless communication systems--Security measures, Computer network protocols, Computer security, Computer networks--Security measures
- Format
- Document (PDF)
- Title
- Joint TCP congestion control and wireless-link scheduling for mobile Internet applications.
- Creator
- Li, Zhaoquan., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
The Transmission Control Protocol (TCP) is one of the core protocols of the Internet protocol suite, which is used by major Internet applications such as World Wide Web, email, remote administration and file transfer. TCP implements scalable and distributed end-to-end congestion control algorithms to share network resources among competing users. TCP was originally designed primarily for wired networks, and it has performed remarkably well as the Internet scaled up by six orders of magnitude...
Show moreThe Transmission Control Protocol (TCP) is one of the core protocols of the Internet protocol suite, which is used by major Internet applications such as World Wide Web, email, remote administration and file transfer. TCP implements scalable and distributed end-to-end congestion control algorithms to share network resources among competing users. TCP was originally designed primarily for wired networks, and it has performed remarkably well as the Internet scaled up by six orders of magnitude in the past decade. However, many studies have shown that the unmodified standard TCP performs poorly in networks with large bandwidth-delay products and/or lossy wireless links. In this thesis, we analyze the problems TCP exhibits in the wireless communication environment, and develop joint TCP congestion control and wireless-link scheduling schemes for mobile applications. ... Different from the existing solutions, the proposed schemes can be asynchronously implemented without message passing among network nodes; thus they are readily deployable with current infrastructure. Moreover, global convergence/stability of the proposed schemes to optimal equilibrium is established using the Lyapunov method in the network fluid model. Simulation results are provided to evaluate the proposed schemes in practical networks.
Show less - Date Issued
- 2013
- PURL
- http://purl.flvc.org/fcla/dt/3362481
- Subject Headings
- Wireless communication systems, Quality control, Mobile communication systems, Technological innovations, TCP/IP (Computer network protocol), Ad hoc networks (Computer networks), Computer network protocols, Wireless Internet
- Format
- Document (PDF)
- Title
- Design of a signaling gateway to interoperate H.323 and SIP protocols.
- Creator
- Akbarian, Hamid., Florida Atlantic University, Hsu, Sam
- Abstract/Description
-
This thesis proposes a design for a signaling gateway to address the issues of interoperability between H.323 and SIP. The two IP Telephony standards currently compete for the dominance of IP telephony protocols. We investigate and study these two protocols in terms of interoperability. The question central to this thesis is the issue of interoperability between H.323 and SIP. A signaling gateway model is proposed and designed to address and solve this issue. The proposed model includes Call...
Show moreThis thesis proposes a design for a signaling gateway to address the issues of interoperability between H.323 and SIP. The two IP Telephony standards currently compete for the dominance of IP telephony protocols. We investigate and study these two protocols in terms of interoperability. The question central to this thesis is the issue of interoperability between H.323 and SIP. A signaling gateway model is proposed and designed to address and solve this issue. The proposed model includes Call Initialization, Call Setup and Control, Capability Exchange and Call Termination, which are the four fundamental features supported by H.323 and SIP for establishing calls. Furthermore, we design the four internal components, which are common to the four main functions mentioned above. These four components are type checking, decomposition, conversion and reformatting. In addition, we illustrate in six different cases the functionality of the proposed signaling gateway for establishing calls between H.323 and SIP. These six cases also demonstrate the conversion capability of the proposed signaling gateway during a call between H.323 and SIP endpoints.
Show less - Date Issued
- 2001
- PURL
- http://purl.flvc.org/fcla/dt/12784
- Subject Headings
- Internet telephony, Computer network protocols, Packet switching (Data transmission)
- Format
- Document (PDF)
- Title
- Performance evaluation of Bluetooth(TM) network in the presence of self-interference.
- Creator
- Gandhi, Viraf Rusi., Florida Atlantic University, Pandya, Abhijit S.
- Abstract/Description
-
Wireless personal area networks (WPAN) are becoming more and more popular for use by mobile professionals in areas like airports, hotels, or convention centers. The demand for wireless networks is expected to undergo an explosive growth as Bluetooth(TM) capable devices become more and more popular. In such a scenario, it is imperative that designer are aware of the performance characteristics of several Bluetooth(TM) networks operating within the same area. There are several issues that need...
Show moreWireless personal area networks (WPAN) are becoming more and more popular for use by mobile professionals in areas like airports, hotels, or convention centers. The demand for wireless networks is expected to undergo an explosive growth as Bluetooth(TM) capable devices become more and more popular. In such a scenario, it is imperative that designer are aware of the performance characteristics of several Bluetooth(TM) networks operating within the same area. There are several issues that need consideration like security, self-interference and adjacent network interference. The objective of this research is to evaluate the performance of a Bluetooth(TM) network in the presence of self-interference which included adjacent and co-channel interference from neighboring Bluetooth(TM) networks. Specific to the above topics of interest, the following research tasks are performed: (1) The magnitude of self-interference problem in Bluetooth(TM) networks. (2) The system throughput is evaluated by varying duty cycles of the various networks. (3) The pathloss difference is measured between the desired and the interfering device.
Show less - Date Issued
- 2000
- PURL
- http://purl.flvc.org/fcla/dt/12679
- Subject Headings
- Bluetooth technology, Telecommunication--Equipment and supplies, Computer network protocols
- Format
- Document (PDF)
- Title
- Security in voice over IP networks.
- Creator
- Pelaez, Juan C., Florida Atlantic University, Fernandez, Eduardo B., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Voice over IP (VoIP) is revolutionizing the global communications system by allowing human voice and fax information to travel over existing packet data networks along with traditional data packets. The convergence of voice and data in one simplified network brings both benefits and constraints to users. Among the several issues that need to be addressed when deploying this technology, security is one of the most critical. This thesis will present a combination of security patterns based on...
Show moreVoice over IP (VoIP) is revolutionizing the global communications system by allowing human voice and fax information to travel over existing packet data networks along with traditional data packets. The convergence of voice and data in one simplified network brings both benefits and constraints to users. Among the several issues that need to be addressed when deploying this technology, security is one of the most critical. This thesis will present a combination of security patterns based on the systematic analysis of attacks against a VoIP network and the existing techniques to mitigate these attacks, providing good practices for all IP telephony systems. The VoIP Security Patterns which are based on object-oriented modeling, will help network designers to improve the level of security not only in voice but also in data, video, and fax over IP networks.
Show less - Date Issued
- 2004
- PURL
- http://purl.flvc.org/fcla/dt/13190
- Subject Headings
- Internet telephony--Security measures, Computer network protocols, Multimedia 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
- Correctness analysis of cache conherence protocols using Petri nets.
- Creator
- Hassan, Ahmed Kamal., Florida Atlantic University, Mahgoub, Imad
- Abstract/Description
-
The use of cache memories in multiprocessor systems increases the overall systems performance. Caches reduce the amount of network traffic and provide a solution to the memory contention problem. However, caches introduce memory consistency problems. The existence of multiple cache copies of a memory block will result in an inconsistent view of memory if one processor changes a value in its associated cache. Cache coherence protocols are algorithms designed in software or hardware to maintain...
Show moreThe use of cache memories in multiprocessor systems increases the overall systems performance. Caches reduce the amount of network traffic and provide a solution to the memory contention problem. However, caches introduce memory consistency problems. The existence of multiple cache copies of a memory block will result in an inconsistent view of memory if one processor changes a value in its associated cache. Cache coherence protocols are algorithms designed in software or hardware to maintain memory consistency. With the increased complexity of some of the more recent protocols, testing for the correctness of these protocols becomes an issue that requires more elaborate work. In this thesis, correctness analysis of a selected group of representative cache coherence protocols was performed using Petri nets as a modeling and analysis tool. First, the Petri net graphs for these protocols were designed. These graphs were built by following the logical and coherence actions performed by the protocols in response to the different processors' requests that threatens memory consistency. Correctness analysis was then performed on these graphs.
Show less - Date Issued
- 1997
- PURL
- http://purl.flvc.org/fcla/dt/15366
- Subject Headings
- Cache memory, Multiprocessors, Computer network protocols, Petri nets
- Format
- Document (PDF)
- Title
- A model to evaluate the effect of interference on Bluetooth functionality.
- Creator
- Puttamreddy, Jaideepesh., Florida Atlantic University, Shankar, Ravi, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
We explored the possible effects of various interferences on Bluetooth devices in the ISM band. We developed a model of Bluetooth and interference from sources such as WLAN devices and Microwave oven, and evaluate the functionality of Bluetooth in the presence of these interferences. As a first step we created Bluetooth, WLAN and Microwave oven models using SPW (Signal Processing Workstation). In our exploration, we undertake three cases: (1) When the Bluetooth is in the presence of only...
Show moreWe explored the possible effects of various interferences on Bluetooth devices in the ISM band. We developed a model of Bluetooth and interference from sources such as WLAN devices and Microwave oven, and evaluate the functionality of Bluetooth in the presence of these interferences. As a first step we created Bluetooth, WLAN and Microwave oven models using SPW (Signal Processing Workstation). In our exploration, we undertake three cases: (1) When the Bluetooth is in the presence of only noises in the channel; (2) When the Bluetooth is in the presence of Microwave oven interference; (3) When the Bluetooth is in the presence of WLAN interference. We show that these models can be used to analyze the interferences on the Bluetooth in the ISM band. Future efforts of our group will be to analyze this Bluetooth model with combined interference from all the sources, to come up with possible solutions to reduce the effect of these interferences.
Show less - Date Issued
- 2001
- PURL
- http://purl.flvc.org/fcla/dt/12800
- Subject Headings
- Bluetooth technology, Computer network protocols, Telecommunication--Equipment and supplies
- Format
- Document (PDF)
- Title
- An Ant Inspired Dynamic Traffic Assignment for VANETs: Early Notification of Traffic Congestion and Traffic Incidents.
- Creator
- Arellano, Wilmer, Mahgoub, Imad, Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Vehicular Ad hoc NETworks (VANETs) are a subclass of Mobile Ad hoc NETworks and represent a relatively new and very active field of research. VANETs will enable in the near future applications that will dramatically improve roadway safety and traffic efficiency. There is a need to increase traffic efficiency as the gap between the traveled and the physical lane miles keeps increasing. The Dynamic Traffic Assignment problem tries to dynamically distribute vehicles efficiently on the road...
Show moreVehicular Ad hoc NETworks (VANETs) are a subclass of Mobile Ad hoc NETworks and represent a relatively new and very active field of research. VANETs will enable in the near future applications that will dramatically improve roadway safety and traffic efficiency. There is a need to increase traffic efficiency as the gap between the traveled and the physical lane miles keeps increasing. The Dynamic Traffic Assignment problem tries to dynamically distribute vehicles efficiently on the road network and in accordance with their origins and destinations. We present a novel dynamic decentralized and infrastructure-less algorithm to alleviate traffic congestions on road networks and to fill the void left by current algorithms which are either static, centralized, or require infrastructure. The algorithm follows an online approach that seeks stochastic user equilibrium and assigns traffic as it evolves in real time, without prior knowledge of the traffic demand or the schedule of the cars that will enter the road network in the future. The Reverse Online Algorithm for the Dynamic Traffic Assignment inspired by Ant Colony Optimization for VANETs follows a metaheuristic approach that uses reports from other vehicles to update the vehicle’s perceived view of the road network and change route if necessary. To alleviate the broadcast storm spontaneous clusters are created around traffic incidents and a threshold system based on the level of congestion is used to limit the number of incidents to be reported. Simulation results for the algorithm show a great improvement on travel time over routing based on shortest distance. As the VANET transceivers have a limited range, that would limit messages to reach at most 1,000 meters, we present a modified version of this algorithm that uses a rebroadcasting scheme. This rebroadcasting scheme has been successfully tested on roadways with segments of up to 4,000 meters. This is accomplished for the case of traffic flowing in a single direction on the roads. It is anticipated that future simulations will show further improvement when traffic in the other direction is introduced and vehicles travelling in that direction are allowed to use a store carry and forward mechanism.
Show less - Date Issued
- 2016
- PURL
- http://purl.flvc.org/fau/fd/FA00004566, http://purl.flvc.org/fau/fd/FA00004566
- Subject Headings
- Vehicular ad hoc networks (Computer networks)--Technological innovations., Routing protocols (Computer network protocols), Artificial intelligence., Intelligent transportation systems., Intelligent control systems., Mobile computing., Computer algorithms., Combinatorial optimization.
- Format
- Document (PDF)
- Title
- Label routing protocol: A new cross-layer protocol for multi-hop ad hoc wireless network.
- Creator
- Wang, Yu., Florida Atlantic University, Wu, Jie, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Compared to the traditional wireless network, the multi-hop ad hoc wireless network (simply called ad hoc networks) is self-configurable, dynamic, and distributed. During the past few years, many routing protocols have been proposed for this particular network environment. While in wired and optical networks, multi-protocol label switching (MPLS) has clearly shown its advantages in routing and switching such as flexibility, high efficiency, scalability, and low cost, however MPLS is complex...
Show moreCompared to the traditional wireless network, the multi-hop ad hoc wireless network (simply called ad hoc networks) is self-configurable, dynamic, and distributed. During the past few years, many routing protocols have been proposed for this particular network environment. While in wired and optical networks, multi-protocol label switching (MPLS) has clearly shown its advantages in routing and switching such as flexibility, high efficiency, scalability, and low cost, however MPLS is complex and does not consider the mobility issue for wireless networks, especially for ad hoc networks. This thesis migrates the label concept into the ad hoc network and provides a framework for the efficient Label Routing Protocol (LRP) in such a network. The MAC layer is also optimized with LRP for shorter delay, power saving, and higher efficiency. The simulation results show that the delay is improved significantly with this cross-layer routing protocol.
Show less - Date Issued
- 2006
- PURL
- http://purl.flvc.org/fcla/dt/13321
- Subject Headings
- Computer network protocols, Wireless communication systems, Mobile computing, Computer algorithms, MPLS standard, Operating systems (Computers)
- Format
- Document (PDF)
- Title
- Quorum based IP autoconfiguration in mobile ad hoc networks.
- Creator
- Xu, Tinghui., Florida Atlantic University, Wu, Jie, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
IP address autoconfiguration poses a challenge for mobile ad-hoc networks (MANETs) because it has to be done to ensure correct routing. An IP autoconfiguration protocol that is based on quorum voting is proposed. Nodes are distributed configured when a write quorum can be collected. Making the compromise between message overhead and data consistency, quorum voting enforces data consistency by ensuring fresh read on every access so that each node is configured with a unique IP address. The...
Show moreIP address autoconfiguration poses a challenge for mobile ad-hoc networks (MANETs) because it has to be done to ensure correct routing. An IP autoconfiguration protocol that is based on quorum voting is proposed. Nodes are distributed configured when a write quorum can be collected. Making the compromise between message overhead and data consistency, quorum voting enforces data consistency by ensuring fresh read on every access so that each node is configured with a unique IP address. The protocol is scalable since the configuration information is maintained locally and no central server is involved. Extensive experiments are carried out comparing the configuration latency, message overhead and address reclamation cost between our protocol and existing stateful protocols. The simulation results show that nodes are configured in lower latency and the message overhead for maintaining the network is fairly low. Moreover, the proposed protocol greatly enhances the address availability by keeping proper redundancy.
Show less - Date Issued
- 2006
- PURL
- http://purl.flvc.org/fcla/dt/13362
- Subject Headings
- TCP/IP (Computer network protocol), Computer network architectures, Mobile communication systems, Wireless communication systems
- Format
- Document (PDF)
- Title
- QUIC-TCP: validation of QUIC-TCP through network simulations.
- Creator
- Boughen, Brian, Wang, Xin, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
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The scalability of QUIC-TCP was examined by expanding previous developmental 11-node, 4-flow topology to over 30 nodes with 11 flows to validate QUIC-TCP for larger networks. The topology was simulated using ns-2 network simulator with the same ns-2 module of FAST-TCP modified to produce QUIC-TCP agent that the original development used. A symmetrical topology and a random topology were examined. Fairness, aggregate throughput and the object of the utility function were used as validation...
Show moreThe scalability of QUIC-TCP was examined by expanding previous developmental 11-node, 4-flow topology to over 30 nodes with 11 flows to validate QUIC-TCP for larger networks. The topology was simulated using ns-2 network simulator with the same ns-2 module of FAST-TCP modified to produce QUIC-TCP agent that the original development used. A symmetrical topology and a random topology were examined. Fairness, aggregate throughput and the object of the utility function were used as validation criteria. It was shown through simulation that QUICTCP optimized the utility function and demonstrated a good balance between aggregate throughput and fairness; therefore QUIC-TCP is indeed scalable to larger networks.
Show less - Date Issued
- 2013
- PURL
- http://purl.flvc.org/fau/fd/FA0004007
- Subject Headings
- Ad hoc networks (computer networks), Embedded computer systems -- Programming, QUIC TCP (Computer network protocol), Wireless communication systems
- Format
- Document (PDF)
- Title
- Simulation study of beacon time synchronization algorithm in low rate wireless personal area networks.
- Creator
- Shrivastav, Madhu., Florida Atlantic University, Mahgoub, Imad, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
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In a beacon-enabled network, nodes send beacons when they are ready to transmit or receive messages from the other sensors in their communication range. If the beacons are not synchronized in time, a sensor might receive more than one beacon and hence will not be able to demodulate the beacon, thereby, being isolated from the network. As a result coverage nulls are introduced in the system. To address the above mentioned issues, Motorola Labs have proposed an algorithm for synchronizing the...
Show moreIn a beacon-enabled network, nodes send beacons when they are ready to transmit or receive messages from the other sensors in their communication range. If the beacons are not synchronized in time, a sensor might receive more than one beacon and hence will not be able to demodulate the beacon, thereby, being isolated from the network. As a result coverage nulls are introduced in the system. To address the above mentioned issues, Motorola Labs have proposed an algorithm for synchronizing the beacons in a wireless personal area network. In this thesis, extensive study of the proposed beacon time synchronization algorithm is done using OPNET as a simulation tool. Simulation is carried out by designing a detailed model of the algorithm using IEEE 802.15.4 as a reference. In depth analysis of the simulation results has been carried out. The results obtained are compared with those of existing time synchronization methods.
Show less - Date Issued
- 2005
- PURL
- http://purl.flvc.org/fcla/dt/13227
- Subject Headings
- Wireless LANs, Extranets (Computer networks), Wireless communication systems, Data transmission systems, Computer network protocols, Home computer networks
- Format
- Document (PDF)
- Title
- Experimental implementation of the new prototype in Linux.
- Creator
- Han, Gee Won., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
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The Transmission Control Protocol (TCP) is one of the core protocols of the Internet protocol suite. In the wired network, TCP performs remarkably well due to its scalability and distributed end-to-end congestion control algorithms. However, many studies have shown that the unmodified standard TCP performs poorly in networks with large bandwidth-delay products and/or lossy wireless links. In this thesis, we analyze the problems TCP exhibits in the wireless communication and develop TCP...
Show moreThe Transmission Control Protocol (TCP) is one of the core protocols of the Internet protocol suite. In the wired network, TCP performs remarkably well due to its scalability and distributed end-to-end congestion control algorithms. However, many studies have shown that the unmodified standard TCP performs poorly in networks with large bandwidth-delay products and/or lossy wireless links. In this thesis, we analyze the problems TCP exhibits in the wireless communication and develop TCP congestion control algorithm for mobile applications. We show that the optimal TCP congestion control and link scheduling scheme amounts to window-control oriented implicit primaldual solvers for underlying network utility maximization. Based on this idea, we used a scalable congestion control algorithm called QUeueIng-Control (QUIC) TCP where it utilizes queueing-delay based MaxWeight-type scheduler for wireless links developed in [34]. Simulation and test results are provided to evaluate the proposed schemes in practical networks.
Show less - Date Issued
- 2013
- PURL
- http://purl.flvc.org/fcla/dt/3362375
- Subject Headings
- Ad hoc networks (Computer networks), Wireless sensor networks, Embedded computer systems, Programming, Operating systems (Computers), Network performance (Telecommunication), TCP/IP (Computer network protocol)
- Format
- Document (PDF)
- Title
- Channel Assignment in Cognitive Radio Wireless Networks.
- Creator
- Wu, Yueshi, Cardei, Mihaela, Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
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Cognitive radio technology that enables dynamic spectrum access has been a promising solution for the spectrum scarcity problem. Cognitive radio networks enable the communication on both licensed and unlicensed channels, having the potential to better solve the interference and collision issues. Channel assignment is of great importance in cognitive radio networks. When operating on licensed channels, the objective is to exploit spectrum holes through cognitive communication, giving priority...
Show moreCognitive radio technology that enables dynamic spectrum access has been a promising solution for the spectrum scarcity problem. Cognitive radio networks enable the communication on both licensed and unlicensed channels, having the potential to better solve the interference and collision issues. Channel assignment is of great importance in cognitive radio networks. When operating on licensed channels, the objective is to exploit spectrum holes through cognitive communication, giving priority to the primary users. In this dissertation, we focus on the development of efficient channel assignment algorithms and protocols to improve network performance for cognitive radio wireless networks. The first contribution is on channel assignment for cognitive radio wireless sensor networks aiming to provide robust topology control, as well as to increase network throughput and data delivery rate. The approach is then extended to specific cognitive radio network applications achieving improved performances.
Show less - Date Issued
- 2016
- PURL
- http://purl.flvc.org/fau/fd/FA00004750, http://purl.flvc.org/fau/fd/FA00004750
- Subject Headings
- Cognitive radio networks--Technological innovations., Wireless communication systems--Technological innovations., Ad hoc networks (Computer networks), Routing protocols (Computer network protocols)
- Format
- Document (PDF)
- Title
- Connected Dominating Set in Wireless Ad Hoc Networks: Variations with Applications.
- Creator
- Yang, Shuhui, Wu, Jie, Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
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Wireless ad hoc networks (or simply ad hoc networks) are infrastructureless multihop networks consisting of mobile or stationary wireless devices, which include mobile ad hoc networks (MANETs) and wireless sensor networks (WSNs). These networks are characterized by limited bandwidth and energy resources, frequent topology changes, and a lack of central control. These characteristics lead to the research challenges of ad hoc networks. The algorithms designed for ad hoc networks should be...
Show moreWireless ad hoc networks (or simply ad hoc networks) are infrastructureless multihop networks consisting of mobile or stationary wireless devices, which include mobile ad hoc networks (MANETs) and wireless sensor networks (WSNs). These networks are characterized by limited bandwidth and energy resources, frequent topology changes, and a lack of central control. These characteristics lead to the research challenges of ad hoc networks. The algorithms designed for ad hoc networks should be localized, selforganizing, and energy efficient. A connected dominating set (CDS) is frequently used in ad hoc networks as a virtual backbone to support efficient routing, service discovery, and area monitoring. In addition, efficient broadcasting (i.e., finding a small set of forward nodes to ensure full delivery) can be viewed as forming a CDS on-the-fly. The periodically maintained virtual backbone is called a static CDS, and the temporarily formed forward node set is called a dynamk CDS. For efficiency and robustness, the ideal CDS construction algorithm is lightweight, has fast convergence, and minimizes the CDS size. Recently, due to some specific applications and new techniques, the concept of a connected dominating set can be modified or further extended for more efficient usage. This dissertation focuses on the variations with applications of the connected dominating set, designing new concepts, and developing new algorithms for them. A review of CDS construction algorithms for ad hoc networks has been provided at the beginning. An efficient scheme, called Rule K, has been proposed for static CDS construction. Rule K achieves a probabilistic constant upper bound on the expected CDS size, which is currently the best known performance guarantee for localized CDS algorithms. Several CDS algorithms are extended to generate the extended CDS, which exploits the cooperative communication technique to further reduce the size of CDS. A k-coverage set is developed for higher robustness. With the equipment of directional antennas , the transmission can be restricted to some certain directions to reduce interference and energy consumption. The corresponding directional CDS is discussed. Finally, a wireless sensor and actor network (WSAN) is introduced and localized algorithms are designed for it.
Show less - Date Issued
- 2007
- PURL
- http://purl.flvc.org/fau/fd/FA00012580
- Subject Headings
- Computer network protocols, Wireless communication systems--Design and construction, Mobile computing, Computer algorithms
- Format
- Document (PDF)
