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Digital Communications and Networking

2010

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Articles 1 - 30 of 106

Full-Text Articles in Computer Engineering

Anonymous Query Processing In Road Networks, Kyriakos Mouratidis, Man Lung Yiu Dec 2010

Anonymous Query Processing In Road Networks, Kyriakos Mouratidis, Man Lung Yiu

Kyriakos MOURATIDIS

The increasing availability of location-aware mobile devices has given rise to a flurry of location-based services (LBSs). Due to the nature of spatial queries, an LBS needs the user position in order to process her requests. On the other hand, revealing exact user locations to a (potentially untrusted) LBS may pinpoint their identities and breach their privacy. To address this issue, spatial anonymity techniques obfuscate user locations, forwarding to the LBS a sufficiently large region instead. Existing methods explicitly target processing in the euclidean space and do not apply when proximity to the users is defined according to network distance ...


On-Line Discovery Of Hot Motion Paths, Dimitris Sacharidis, Kostas Patroumpas, Manolis Terrovitis, Verena Kantere, Michalis Potamias, Kyriakos Mouratidis, Timos Sellis Dec 2010

On-Line Discovery Of Hot Motion Paths, Dimitris Sacharidis, Kostas Patroumpas, Manolis Terrovitis, Verena Kantere, Michalis Potamias, Kyriakos Mouratidis, Timos Sellis

Kyriakos MOURATIDIS

We consider an environment of numerous moving objects, equipped with location-sensing devices and capable of communicating with a central coordinator. In this setting, we investigate the problem of maintaining hot motion paths, i.e., routes frequently followed by multiple objects over the recent past. Motion paths approximate portions of objects' movement within a tolerance margin that depends on the uncertainty inherent in positional measurements. Discovery of hot motion paths is important to applications requiring classification/profiling based on monitored movement patterns, such as targeted advertising, resource allocation, etc. To achieve this goal, we delegate part of the path extraction process ...


Continuous Monitoring Of Spatial Queries In Wireless Broadcast Environments, Kyriakos Mouratidis, Spiridon Bakiras, Dimitris Papadias Dec 2010

Continuous Monitoring Of Spatial Queries In Wireless Broadcast Environments, Kyriakos Mouratidis, Spiridon Bakiras, Dimitris Papadias

Kyriakos MOURATIDIS

Wireless data broadcast is a promising technique for information dissemination that leverages the computational capabilities of the mobile devices in order to enhance the scalability of the system. Under this environment, the data are continuously broadcast by the server, interleaved with some indexing information for query processing. Clients may then tune in the broadcast channel and process their queries locally without contacting the server. Previous work on spatial query processing for wireless broadcast systems has only considered snapshot queries over static data. In this paper, we propose an air indexing framework that 1) outperforms the existing (i.e., snapshot) techniques ...


Optimal Matching Between Spatial Datasets Under Capacity Constraints, Hou U Leong, Kyriakos Mouratidis, Man Lung Yiu, Nikos Mamoulis Dec 2010

Optimal Matching Between Spatial Datasets Under Capacity Constraints, Hou U Leong, Kyriakos Mouratidis, Man Lung Yiu, Nikos Mamoulis

Kyriakos MOURATIDIS

Consider a set of customers (e.g., WiFi receivers) and a set of service providers (e.g., wireless access points), where each provider has a capacity and the quality of service offered to its customers is anti-proportional to their distance. The capacity constrained assignment (CCA) is a matching between the two sets such that (i) each customer is assigned to at most one provider, (ii) every provider serves no more customers than its capacity, (iii) the maximum possible number of customers are served, and (iv) the sum of Euclidean distances within the assigned provider-customer pairs is minimized. Although max-flow algorithms ...


Continuous Spatial Assignment Of Moving Users, Leong Hou U, Kyriakos Mouratidis, Nikos Mamoulis Dec 2010

Continuous Spatial Assignment Of Moving Users, Leong Hou U, Kyriakos Mouratidis, Nikos Mamoulis

Kyriakos MOURATIDIS

Consider a set of servers and a set of users, where each server has a coverage region (i.e., an area of service) and a capacity (i.e., a maximum number of users it can serve). Our task is to assign every user to one server subject to the coverage and capacity constraints. To offer the highest quality of service, we wish to minimize the average distance between users and their assigned server. This is an instance of a well-studied problem in operations research, termed optimal assignment. Even though there exist several solutions for the static case (where user locations ...


Shortest Path Computation On Air Indexes, Georgios Kellaris, Kyriakos Mouratidis Dec 2010

Shortest Path Computation On Air Indexes, Georgios Kellaris, Kyriakos Mouratidis

Kyriakos MOURATIDIS

Shortest path computation is one of the most common queries in location-based services that involve transportation net- works. Motivated by scalability challenges faced in the mo- bile network industry, we propose adopting the wireless broad- cast model for such location-dependent applications. In this model the data are continuously transmitted on the air, while clients listen to the broadcast and process their queries locally. Although spatial problems have been considered in this environment, there exists no study on shortest path queries in road networks. We develop the rst framework to compute shortest paths on the air, and demonstrate the practicality and ...


Preference Queries In Large Multi-Cost Transportation Networks, Kyriakos Mouratidis, Yimin Lin, Man Lung Yiu Dec 2010

Preference Queries In Large Multi-Cost Transportation Networks, Kyriakos Mouratidis, Yimin Lin, Man Lung Yiu

Kyriakos MOURATIDIS

Research on spatial network databases has so far considered that there is a single cost value associated with each road segment of the network. In most real-world situations, however, there may exist multiple cost types involved in transportation decision making. For example, the different costs of a road segment could be its Euclidean length, the driving time, the walking time, possible toll fee, etc. The relative significance of these cost types may vary from user to user. In this paper we consider such multi-cost transportation networks (MCN), where each edge (road segment) is associated with multiple cost values. We formulate ...


The Wireless Control Network: Synthesis And Robustness, Miroslav Pajic, Shreyas Sundaram, Jerome Le Ny, George J. Pappas, Rahul Mangharam Dec 2010

The Wireless Control Network: Synthesis And Robustness, Miroslav Pajic, Shreyas Sundaram, Jerome Le Ny, George J. Pappas, Rahul Mangharam

Real-Time and Embedded Systems Lab (mLAB)

We consider the problem of stabilizing a plant with a network of resource constrained wireless nodes. Traditional networked control schemes are designed with one of the nodes in the network acting as a dedicated controller, while the other nodes simply route information to and from the controller and the plant. We introduce the concept of a Wireless Control Network (WCN) where the entire network itself acts as the controller. Specifically, at each time-step, each node updates its internal state to be a linear combination of the states of the nodes in its neighborhood. We show that this causes the entire ...


The Wireless Control Network: Monitoring For Malicious Behavior, Shreyas Sundaram, Miroslav Pajic, Christoforos N. Hadjicostis, Rahul Mangharam, George J. Pappas Dec 2010

The Wireless Control Network: Monitoring For Malicious Behavior, Shreyas Sundaram, Miroslav Pajic, Christoforos N. Hadjicostis, Rahul Mangharam, George J. Pappas

Real-Time and Embedded Systems Lab (mLAB)

We consider the problem of stabilizing a plant with a network of resource constrained wireless nodes. In a companion paper, we developed a protocol where each node repeatedly transmits a linear combination of the values in its neighborhood. For certain topologies, we showed that these linear combinations can be designed so that the closed loop system is stable (i.e., the wireless network itself acts as a controller for the plant). In this paper, we design a Intrusion Detection System (IDS) for this control scheme, which observes the transmissions of certain nodes in the network and uses that information to ...


Network Security Toolkit Including Heuristic Solutions For Trust System Placement And Network Obfuscation, Gabriel H. Greve Dec 2010

Network Security Toolkit Including Heuristic Solutions For Trust System Placement And Network Obfuscation, Gabriel H. Greve

Theses and Dissertations

For Part I, a supervisory control and data acquisition (SCADA) network consists of a group stations and substations in a portion of the power grid. The use of Internet technology in SCADA communications as well as other factors has caused vulnerabilities. One idea to help mitigate this risk is to strategically place trust nodes to compartmentalize and secure the SCADA systems without disturbing its finely honed processes. The trust nodes combine firewall and intrusion detection technology to provide more secure communication. An optimal solution to this problem has already been developed using a mixed-integer linear programming model. Because the problem ...


A Comprehensive Analysis Of Lte Physical Layer, Fahimeh Rezaei Dec 2010

A Comprehensive Analysis Of Lte Physical Layer, Fahimeh Rezaei

Theses, Dissertations, & Student Research in Computer Electronics & Engineering

The 3rd Generation Partnership Project (3GPP) introduced Long Term Evolution (LTE) as the 3rd generation of mobile communication standards. LTE Release 8 describes a mobile communication standard which supports up to 300 Mbps of data transmission in downlink using the OFDM scheme as well as up to 75 Mbps throughput for uplink using the SC-FDMA modulation. In this thesis, an in-depth study of LTE performance based on Release 8 is conducted for uplink and downlink under different scenarios. The main objective of this study is to investigate a comprehensive analysis of physical layer throughput of LTE Release8 based on standard ...


Cross-Layer Optimized Wireless Multimedia Networking, Dalei Wu Dec 2010

Cross-Layer Optimized Wireless Multimedia Networking, Dalei Wu

Theses, Dissertations, & Student Research in Computer Electronics & Engineering

Multimedia communications, especially real-time video communications, is expected to be the major application of the next-generation wireless networks. However, bringing delay-sensitive and loss-tolerant multimedia services based on the current wireless Internet is a very challenging task. In this dissertation, we address cross-layer optimized wireless multimedia networking from both theoretical and practical perspectives. In the first part of the dissertation, we propose cross-layer optimization frameworks for real-time video communications over wireless networks, where the expected received video quality is adopted as the objective function. With the user-centric objective function, we first study content-aware video communications in single-hop wireless networks by exploring ...


Use Of Mobile Phone Computing For Development Of Student 21st Century Skills, Susan M. Merritt, R. Lara Lee Dec 2010

Use Of Mobile Phone Computing For Development Of Student 21st Century Skills, Susan M. Merritt, R. Lara Lee

Cornerstone 2 Reports : Community Outreach and Empowerment Through Service Learning and Volunteerism

Mobile phone computing enables immediate capture and transfer of data, images, notes and experiences from the field to a repository where retrieval, analysis, edits, aggregation, and further development are possible. Immediate findings and later results can be shared on the Web with local and global communities, and development of integrated service learning projects in concert with underserved communities is possible using this mode of information gathering and sharing.

Mobile phone computing incorporates moments when participants build tomorrow's skills while addressing today's learning goals. Use of digital tools and supporting resources bring real world problems into focus. Mobile phone ...


Security@Web: Teaching Security With Alignment In Trust On The Web (Final Report), Li-Chiou Chen, Mary Long Dec 2010

Security@Web: Teaching Security With Alignment In Trust On The Web (Final Report), Li-Chiou Chen, Mary Long

Cornerstone 3 Reports : Interdisciplinary Informatics

No abstract provided.


Sports-Tool, Bryant Ung Dec 2010

Sports-Tool, Bryant Ung

Computer Science and Software Engineering

Creating events and finding people to play sports is a hard thing to do. The solution to this problem is to provide a web based interactive site that allows people to create and join different type of events and interact with each other by creating teams.


Dynamic Distributed Programming And Applications To Swap Edge Problem, Feven Z. Andemeskel Dec 2010

Dynamic Distributed Programming And Applications To Swap Edge Problem, Feven Z. Andemeskel

UNLV Theses, Dissertations, Professional Papers, and Capstones

Link failure is a common reason for disruption in communication networks. If communication between processes of a weighted distributed network is maintained by a spanning tree T, and if one edge e of T fails, communication can be restored by finding a new spanning tree, T’. If the network is 2-edge connected, T’ can always be constructed by replacing e by a single edge, e’, of the network. We refer to e’ as a swap edge of e.


The best swap edge problem is to find the best choice of e’, that is, that e which causes the new spanning ...


Self-Stabilizing Group Membership Protocol, Mahesh Subedi Dec 2010

Self-Stabilizing Group Membership Protocol, Mahesh Subedi

UNLV Theses, Dissertations, Professional Papers, and Capstones

In this thesis, we consider the problem of partitioning a network into groups of bounded diameter.

Given a network of processes X and a constant D, the group partition problem is the problem of finding a D-partition of X, that is, a partition of X into disjoint connected subgraphs, which we call groups, each of diameter no greater than D. The minimal group partition problem is to find a D-partition {G1, ... Gm} of X such that no two groups can be combined; that is, for any Gi and Gj, where i ≠ j, either Gi U Gj is disconnected or Gi ...


Self-Stabilizing Leader Election In Dynamic Networks, Hema Piniganti Dec 2010

Self-Stabilizing Leader Election In Dynamic Networks, Hema Piniganti

UNLV Theses, Dissertations, Professional Papers, and Capstones

The leader election problem is one of the fundamental problems in distributed computing. It has applications in almost every domain. In dynamic networks, topology is expected to change frequently. An algorithm A is self-stabilizing if, starting from a completely arbitrary configuration, the network will eventually reach a legitimate configuration.

Note that any self-stabilizing algorithm for the leader election problem is also an algorithm for the dynamic leader election problem, since when the topology of the network changes, we can consider that the algorithm is starting over again from an arbitrary state. There are a number of such algorithms in the ...


Anubis: An Attestation Protocol For Distributed Context-Aware Applications, Senaka Buthpitiya, Feng-Tso Sun, Heng-Tze Chen, Patrick Tague, Martin Griss, Anind Dey Nov 2010

Anubis: An Attestation Protocol For Distributed Context-Aware Applications, Senaka Buthpitiya, Feng-Tso Sun, Heng-Tze Chen, Patrick Tague, Martin Griss, Anind Dey

Patrick Tague

Sharing sensitive context information among multiple distributed components in mobile environments introduces major security concerns. The distributed sensing, processing and actuating components of these applications can be compromised and modified or impersonated to extract private and confidential information or to inject false information. In this paper we present the Anubis protocol for remote code attestation and access control of distributed components using remote execution of trusted code. Our Anubis protocol leverages previous work in the fields of wireless sensor networks and secure web browsing. Anubis allows new components to be introduced to the environment without updating existing components. Our implementation ...


The Kerf Toolkit For Intrusion Analysis, Javed A. Aslam, Sergey Bratus, David Kotz, Ron Peterson, Brett Tofel, Daniela Rus Nov 2010

The Kerf Toolkit For Intrusion Analysis, Javed A. Aslam, Sergey Bratus, David Kotz, Ron Peterson, Brett Tofel, Daniela Rus

Javed A. Aslam

To aid system administrators with post-attack intrusion analysis, the Kerf toolkit provides an integrated front end and powerful correlation and data-representation tools, all in one package.


On Iterative Decoding Of Two-Level Superposition Codes For Cooperative Broadcasting Based On Qpsk And 4-Pam Constellations, Robert H. Morelos-Zaragoza Nov 2010

On Iterative Decoding Of Two-Level Superposition Codes For Cooperative Broadcasting Based On Qpsk And 4-Pam Constellations, Robert H. Morelos-Zaragoza

Robert Henry Morelos-Zaragoza

This paper considers iterative decoding of two-level superposition codes used in cooperative broadcasting over wireless networks. The coding scheme consists of two low-density parity-check (LDPC) codes combined using Plotkin’s |u|u+v|-construction and provides two levels of error protection.


Design And Implementation Of User Level Socket Application Programming Interface With Socket Splitting And Mediation, Scott Walter Holzer Nov 2010

Design And Implementation Of User Level Socket Application Programming Interface With Socket Splitting And Mediation, Scott Walter Holzer

Master's Theses and Project Reports

Over the past few decades, the size and scope of the Internet has grown exponentially. In order to maintain support for legacy clients, new applications and services have been limited by dependence on traditional sockets and TCP, which provide no support for modifying endpoints after connection setup. This forces applications to implement their own logic to reroute communications to take advantage of composable services or handle failover. Some solutions have added socket operations that allow for endpoints to be redirected on the fly, but these have been limited in scope to handling failover and load balancing.

We present two new ...


Assessing Value Creation And Value Capture In Digital Business Ecosystems, Ravi S. Sharma, Francis Pereira, Narayan Ramasubbu, Margaret Tan, Feichin Ted Tschang (Or F. Ted Tschang) Nov 2010

Assessing Value Creation And Value Capture In Digital Business Ecosystems, Ravi S. Sharma, Francis Pereira, Narayan Ramasubbu, Margaret Tan, Feichin Ted Tschang (Or F. Ted Tschang)

Research Collection Lee Kong Chian School of Business

Interest in business modeling of technology enterprises – the activity of designing the architecture for revenues, costs, products and/or services delivery and the overall value of an enterprise – has risen to prominence with the global crossing of the Internet chasm. However, as several studies have pointed out (c.f., Osterwalder, Pigneur & Tucci, 2005; Teece 2010; Zott & Amit, 2010), the investigations of business models and their fit with the strategy of an enterprise, have received little scholarly attention. In this article we formulate a framework, called ADVISOR, for modeling the business strategies of enterprises in the Interactive Digital Media (IDM) industry. We focus ...


Improving Anti-Jamming Capability And Increasing Jamming Impact With Mobility Control, Patrick Tague Oct 2010

Improving Anti-Jamming Capability And Increasing Jamming Impact With Mobility Control, Patrick Tague

Patrick Tague

The impact of a jamming attack on wireless communication depends on a number of physical characteristics and network protocol parameters. In particular, it depends on the relative geometries of the adversarial network of jammers and the network under attack. Hence, changes in network geometry achieved through node and jammer mobility can have significant influence on the impact of a jamming attack. In this work, we investigate the use of mobility as a tool to allow both the adversarial network and the network under attack to reconfigure their geometry in an attempt to improve attack impact and protocol performance, respectively. We ...


Software Engineering Issues For Mobile Application Development, Tony Wasserman Oct 2010

Software Engineering Issues For Mobile Application Development, Tony Wasserman

Tony Wasserman

This paper provides an overview of important software engineering research issues related to the development of applications that run on mobile devices. Among the topics are development processes, tools, user interface design, application portability, quality, and security.


Safe Inter-Domain Routing Under Diverse Commercial Agreements, Yong Liao, Lixin Gao, Roch A. Guérin, Zhi-Li Zhang Oct 2010

Safe Inter-Domain Routing Under Diverse Commercial Agreements, Yong Liao, Lixin Gao, Roch A. Guérin, Zhi-Li Zhang

Lixin Gao

Commercial agreements drive the routing policies used in today's Internet. The two most extensively studied commercial agreements are transit and peering; however, they are only two of many diverse and continuously evolving commercial agreements that ISPs enter into. So far, the only known practical safe and robust routing policy is Gao and Rexford's policy guideline, which is applicable to transit and peering agreements only. It is, therefore, of importance to identify routing policies that are safe and robust and at the same time capable of accommodating the diverse commercial agreements existing in the Internet. In particular, this paper ...


On The Feasibility And Efficacy Of Protection Routing In Ip Networks, Kin-Wah (Eric) Kwong, Lixin Gao, Roch A. Guérin, Zhi-Li Zhang Oct 2010

On The Feasibility And Efficacy Of Protection Routing In Ip Networks, Kin-Wah (Eric) Kwong, Lixin Gao, Roch A. Guérin, Zhi-Li Zhang

Lixin Gao

With network components increasingly reliable, routing is playing an ever greater role in determining network reliability. This has spurred much activity in improving routing stability and reaction to failures, and rekindled interest in centralized routing solutions, at least within a single routing domain. Centralizing decisions eliminates uncertainty and many inconsistencies, and offers added flexibility in computing routes that meet different criteria. However, it also introduces new challenges; especially in reacting to failures where centralization can increase latency. This paper leverages the flexibility afforded by centralized routing to address these challenges. Specifically, we explore when and how standby backup forwarding options ...


Digital Content Preservation Across Domain Verticals, Soha Maad, Borislav D. Dimitrov Oct 2010

Digital Content Preservation Across Domain Verticals, Soha Maad, Borislav D. Dimitrov

General Practice Articles

The authors present a novel approach to develop scalable systems and services for preserving digital content generated from various application domains. The aim is to deliver an integrative scalable approach for digital content preservation across domain verticals. This would involve consolidating approaches for modeling document workflow, preserving the integrity of heterogeneous data, and developing robust and scalable tools for digital preservation ensuring interoperability across domains verticals. The authors consider various application domains including: healthcare, public, business and finance, media and performing art, and education. The authors focus on specific case studies of digital content preservation across the considered domain verticals ...


Public Consultations On Net Neutrality 2010: Usa, Eu And France, Sulan Wong, Julio Rojas Mora, Eitan Altman Sep 2010

Public Consultations On Net Neutrality 2010: Usa, Eu And France, Sulan Wong, Julio Rojas Mora, Eitan Altman

Julio Rojas-Mora

The evolution of the Internet has come to a point where almost at the same time, governments all around the world feel the need for legislation to regulate the use of the Internet. In preparing the legislation, consultations were called by various governments or by the corresponding regulation bodies. We describe in this paper the various consultations as well as the background related to the Net Neutrality question in each case. Rather than describing the answers to each consultation, which are available and which have already been analyzed, we focus on comparing the consultations and the statistical figures related to ...


The Impact Of Reprovisioning On The Choice Of Shared Versus Dedicated Networks, Soumya Sen, Kristin Yamauchi, Roch Guerin, Kartik Hosanagar Sep 2010

The Impact Of Reprovisioning On The Choice Of Shared Versus Dedicated Networks, Soumya Sen, Kristin Yamauchi, Roch Guerin, Kartik Hosanagar

Departmental Papers (ESE)

As new network services emerge, questions about service deployment and network choices arise. Although shared networks, such as the Internet, offer many advantages, combining heterogeneous services on the same network need not be the right answer as it comes at the cost of increased complexity. Moreover, deploying new services on dedicated networks is becoming increasingly viable, thanks to virtualization technologies. In this work, we introduce an analytical framework that gives Internet Service Providers the ability to explore the trade-offs between shared and dedicated network infrastructures. The framework accounts for factors such as the presence of demand uncertainty for new services ...