Showing papers by "Xiaoyan Hong published in 2013"

Methods and systems for handling transportation reservation requests in a decentralized environment

Abstract: Methods and systems for handling transportation reservation requests in a decentralized environment are discussed herein. An example decentralized system for handling transportation reservation requests may include a road-side device, a hailing device and/or a vehicle device. In the example decentralized system, the road-side device and/or the hailing device can be configured to communicate with the vehicle device using a vehicular communication channel. In some implementations, the vehicular communication channel can be reserved exclusively for vehicle-to-vehicle and vehicle-to-infrastructure communications.

Analysis for bio-inspired thrown-box assisted message dissemination in delay tolerant networks

Abstract: Inspired by biological communication, the strategy of deploying communication and storage equipment called thrown box is proposed to increase message delivery probability and to reduce transmission latency in delay tolerant networks. In this paper, we study the thrown-box assisted message dissemination models by analyzing a few cases on the message delivery rate and related latency distribution. We divide such communications into two processes. We first model the message delivering process among thrown boxes and derive time related message distribution on the boxes. Then we investigate the message collection process to obtain the expected number of informed collectors as a function of time. In addition, we analyze the latency distribution for message collection. Our analysis is derived based on a discrete Markov Chain model. The numerical examples are provided to validate our model and to examine the features of message dissemination under different network scenarios. The factors such as message relay and lifetime are considered. The results show that the tradeoff exists between the number of the boxes and the message lifetime, etc. In summary, our results will help storage management and delay management in DTNs and provide guidelines for applications of search and surveillance.

Feasibility analysis of multi-radio in DSRC vehicular networks

Abstract: Dedicated Short Range Communications (DSRC) is a MAC layer and physical layer standard designed for vehicular networks. A multi-radio based DSRC system can have several noticeable advantages, e.g., shorter hand off latency, larger bandwidth higher spectrum utilization, etc. However, Multiple-radio in DSRC system has to address several issues in terms of Signal to Noise Ratio (SNR) and the deployment. In this paper, we prove that multi-radio DSRC is feasible in future vehicular networks. We evaluate free-space path loss and optional adjacent channel rejections. We analyze the SNR of modulations in DSRC Orthogonal frequency-division multiplexing (OFDM) system, and study the performance of BER according to SNR and FEC. The isolation requirement of antenna pair is discussed later in this paper. We also analyze applicable decoupling methods and technologies to achieve the decoupling requirement. At least one decoupling method could meet the isolation requirement of multi-radio system and can be used in the future multi-radio DSRC networks. This point is supported by our experiment results.

ProtoGENI, a Prototype GENI Under Security Vulnerabilities: An Experiment-Based Security Study

Abstract: ProtoGENI is one of the prototype implementations of global environment for network innovations (GENI). ProtoGENI proposes and executes the GENI control framework, including resource management and allocation for authenticated and authorized experimenters. Security and inevitably are the most important concerns in the whole development process. In this paper, we study and evaluate its security vulnerabilities according to GENI's security goals. We analyze the threat model of ProtoGENI and categorize four broad classes of attacks. Based on the role of an active experimenter, we demonstrate experiments as proof of the concept that each class of attacks can be successfully launched using common open source network tools. We also present analysis and experiments that show perspectives on the potential risks from an external user. Furthermore, we discuss the feasibility and possible defense strategies on ProtoGENI security with respect to our preliminary experiments and potential future directions. Our contribution lies in examining known vulnerabilities without requiring sophisticated experiments while remaining effective. We have reported our findings to the ProtoGENI Team. Our work indicates that the solutions have been deployed. This paper validates that experiment-based vulnerability exploration is necessary.

Design and analysis of accountable networked and distributed systems

Abstract: This dissertation focuses on the design and analysis of accountable computing for a wide range of networked systems with affordable expense. The central idea is to incorporate accountability, a long-neglected security objective, into the design and implementation of modern computing systems. Broadly speaking, accountability in the cyber-security domain means that every entity ought to be held responsible for its behavior, and that there always exists undeniable and verifiable evidence linking each event to the liable entities. This dissertation studies accountable computing in three different contexts, including traditional distributed systems, cloud computing, and the Smart Grid. We first propose a quantitative model called P-Accountability to assess the degree of system accountability. P-Accountability consists of a flat model and a hierarchical model. Our results show that P-Accountability is an effective metric to evaluate general distributed systems such as PeerReview [1] in terms of accountability. Next, we develop Accountable MapReduce for cloud computing to prevent malicious working machines from manipulating the processing results. To achieve this goal, we set up a group of auditors to perform an Accountability-Test (A-test) that checks all working machines and detects malicious nodes in real time. Finally, we investigate the accountability issues in the neighborhood area smart grid. A mutual inspection scheme is presented to enable non-repudiation for metering. In addition, we propose and analyze a suite of algorithms to identify malicious meters for the detection of energy theft. iii DEDICATION This dissertation is dedicated to everyone who helped me, guided me, and inspired me.

Identifying the Intertwined Links Between Mobility and Routing in Opportunistic Networks

Abstract: Mobility intertwines with routing protocols play a vital role in opportunistic networks. First and foremost, mobility creates opportunities for mobile nodes to connect and communicate when they encounter. A series of encounter opportunities can spread a message among many nodes and to a large area until eventual delivery. Further, mobility properties, when utilized by routing protocols, can greatly improve performance. This chapter will trace the research on mobility and mobility enabled message dissemination approaches, and will present a survey over mobility models, analytical results on motion characteristics, and routing strategies that largely rely on mobility. These three components intertwine and show a strong research agenda in opportunistic networks. The survey shows that analytical mobility properties and abstracted graphic features are significant to the success of some routing protocols. By emphasizing on the three components, the survey will help in developing novel integrated mobility and message dissemination solutions for opportunistic networks.

EDA: an enhanced dual-active algorithm for location privacy preservation inmobile P2P networks

Abstract: Various solutions have been proposed to enable mobile users to access location-based services while preserving their location privacy. Some of these solutions are based on a centralized architecture with the participation of a trustworthy third party, whereas some other approaches are based on a mobile peer-to-peer (P2P) architecture. The former approaches suffer from the scalability problem when networks grow large, while the latter have to endure either low anonymization success rates or high communication overheads. To address these issues, this paper deals with an enhanced dual-active spatial cloaking algorithm (EDA) for preserving location privacy in mobile P2P networks. The proposed EDA allows mobile users to collect and actively disseminate their location information to other users. Moreover, to deal with the challenging characteristics of mobile P2P networks, e.g., constrained network resources and user mobility, EDA enables users (1) to perform a negotiation process to minimize the number of duplicate locations to be shared so as to significantly reduce the communication overhead among users, (2) to predict user locations based on the latest available information so as to eliminate the inaccuracy problem introduced by using some out-of-date locations, and (3) to use a latest-record-highest-priority (LRHP) strategy to reduce the probability of broadcasting fewer useful locations. Extensive simulations are conducted for a range of P2P network scenarios to evaluate the performance of EDA in comparison with the existing solutions. Experimental results demonstrate that the proposed EDA can improve the performance in terms of anonymity and service time with minimized communication overhead.

THUNDER: helping underfunded NPO's distribute electronic resources

Abstract: As federal funding in many public non-profit organizations (NPO's) seems to be dwindling, it is of the utmost importance that efforts are focused on reducing operating costs of needy organizations, such as public schools. Our approach for reducing organizational costs is through the combined benefits of a high performance cloud architecture and low-power, thin-client devices. However, general-purpose private cloud architectures are not easily deployable by average users, or even those with some computing knowledge. For this reason, we propose a new vertical cloud architecture, which is focused on ease of deployment and management, as well as providing organizations with cost-efficient virtualization and storage, and other organization-specific utilities. We postulate that if organizations are provided with on-demand access to electronic resources in a way that is cost-efficient, then the operating costs may be reduced, such that the user experience and organizational efficiency may be increased. In this paper we discuss our private vertical cloud architecture called THUNDER. Additionally, we introduce a number of methodologies that could enable needy non-profit organizations to decrease costs and also provide many additional benefits for the users. Specifically, this paper introduces our current implementation of THUNDER, details about the architecture, and the software system that we have designed to specifically target the needs of underfunded organizations.