Showing papers by "Xiaoming Fu published in 2015"

Efficient Multi-User Computation Offloading for Mobile-Edge Cloud Computing

Abstract: Mobile-edge cloud computing is a new paradigm to provide cloud computing capabilities at the edge of pervasive radio access networks in close proximity to mobile users. In this paper, we first study the multi-user computation offloading problem for mobile-edge cloud computing in a multi-channel wireless interference environment. We show that it is NP-hard to compute a centralized optimal solution, and hence adopt a game theoretic approach for achieving efficient computation offloading in a distributed manner. We formulate the distributed computation offloading decision making problem among mobile device users as a multi-user computation offloading game. We analyze the structural property of the game and show that the game admits a Nash equilibrium and possesses the finite improvement property. We then design a distributed computation offloading algorithm that can achieve a Nash equilibrium, derive the upper bound of the convergence time, and quantify its efficiency ratio over the centralized optimal solutions in terms of two important performance metrics. We further extend our study to the scenario of multi-user computation offloading in the multi-channel wireless contention environment. Numerical results corroborate that the proposed algorithm can achieve superior computation offloading performance and scale well as the user size increases.

LIVE: Lightweight Integrity Verification and Content Access Control for Named Data Networking

Abstract: Named data networking (NDN) is a new paradigm for the future Internet wherein interest and data packets carry content names rather than the current IP paradigm of source and destination addresses. Security is built into NDN by embedding a public key signature in each data packet to enable verification of authenticity and integrity of the content. However, existing heavyweight signature generation and verification algorithms prevent universal integrity verification among NDN nodes, which may result in content pollution and denial of service attacks. Furthermore, caching and location-independent content access disables the capability of a content provider to control content access, e.g., who can cache a content and which end user or device can access it. We propose a lightweight integrity verification (LIVE) architecture, an extension to the NDN protocol, to address these two issues seamlessly. LIVE enables universal content signature verification in NDN with lightweight signature generation and verification algorithms. Furthermore, it allows a content provider to control content access in NDN nodes by selectively distributing integrity verification tokens to authorized nodes. We evaluate the effectiveness of LIVE with open source CCNx project. Our paper shows that LIVE only incurs average 10% delay in accessing contents. Compared with traditional public key signature schemes, the verification delay is reduced by over 20 times in LIVE.

Triadic Closure Pattern Analysis and Prediction in Social Networks

Abstract: We study the problem of group formation in online social networks. In particular, we focus on one of the most important human groups—the triad—and try to understand how closed triads are formed in dynamic networks, by employing data from a large microblogging network as the basis of our study. We formally define the problem of triadic closure prediction and conduct a systematic investigation. The study reveals how user demographics, network characteristics, and social properties influence the formation of triadic closure. We also present a probabilistic graphical model to predict whether three persons will form a closed triad in a dynamic network. Different kernel functions are incorporated into the proposed graphical model to quantify the similarity between triads. Our experimental results with the large microblogging dataset demonstrate the effectiveness (+10 percent over alternative methods in terms of F1-Score) of the proposed model for the prediction of triadic closure formation.

Cooperative Positioning and Tracking in Disruption Tolerant Networks

Abstract: With the increasing number of location-dependent applications, positioning and tracking a mobile device becomes more and more important to enable pervasive and context-aware service. While extensive research has been performed in physical localization and logical localization for satellite, GSM and WiFi communication networks where fixed reference points are densely-deployed, positioning and tracking techniques in a sparse disruption tolerant network (DTN) have not been well addressed. In this paper, we propose a decentralized cooperative method called PulseCounting for DTN localization and a probabilistic tracking method called ProbTracking to confront this challenge. PulseCounting evaluates the user walking steps and movement orientations using accelerometer and electronic compass equipped in cellphones. It estimates user location by accumulating the walking segments, and improves the estimation accuracy by exploiting the encounters of mobile nodes. Several methods to refine the location estimation are discussed, which include the adjustment of trajectory based on reference points and the mutual refinement of location estimation for encountering nodes based on maximum-likelihood. To track user movement, the proposed ProbTracking method uses Markov chain to describe movement patterns and determines the most possible user walking trajectories without full record of user locations. We implemented the positioning and tracking system in Android phones and deployed a testbed in the campus of Nanjing University. Extensive experiments are conducted to evaluate the effectiveness and accuracy of the proposed methods, which show an average deviation of 9m in our system compared to GPS.

On the Security of Software-Defined Networks

Abstract: To achieve a widespread deployment of Software-Defined Networks (SDNs) these networks need to be secure against internal and external misuse. Yet, currently, compromised end hosts, switches, and controllers can be easily exploited to launch a variety of attacks on the network itself. In this work we discuss several attack scenarios, which -- although they have a serious impact on SDN -- have not been thoroughly addressed by the research community so far. We evaluate currently existing solutions against these scenarios and formulate the need for more mature defensive means.

Rating network paths for locality-aware overlay construction and routing

Abstract: This paper investigates the rating of network paths, i.e., acquiring quantized measures of path properties such as round-trip time and available bandwidth. Compared to fine-grained measurements, coarse-grained ratings are appealing in that they are not only informative but also cheap to obtain. Motivated by this insight, we first address the scalable acquisition of path ratings by statistical inference. By observing similarities to recommender systems, we examine the applicability of solutions to a recommender system and show that our inference problem can be solved by a class of matrix factorization techniques. A technical contribution is an active and progressive inference framework that not only improves the accuracy by selectively measuring more informative paths, but also speeds up the convergence for available bandwidth by incorporating its measurement methodology. Then, we investigate the usability of rating-based network measurement and inference in applications. A case study is performed on whether locality awareness can be achieved for overlay networks of Pastry and BitTorrent using inferred ratings. We show that such coarse-grained knowledge can improve the performance of peer selection and that finer granularities do not always lead to larger improvements.

Prototype of an ICN based approach for flexible service chaining in SDN

Abstract: With the widespread use of middleboxes in communication networks (e.g., for services such as Firewall, DPI, accounting, proxies, caching), additional processing beyond simple forwarding has become common. With the emergence of Network Function Virtualization (NFV), dynamically instantiating these functions becomes even more feasible. In addition, chaining such services for packet flows is key to efficiently delivering Internet services. In addition, Software Defined Networking (SDN) gives Internet Service Providers greater flexibility to provision such middlebox based services and route flows through them. However, with the dynamic instantiation of network functions, efficient and scalable use of these services requires separation of the services from their location. In this work, we implement and demonstrate an Information Centric Networking based solution that complements SDN for service chaining and provides benefits such as scalability, flexibility and reliability.

ORICE: an architecture for object resolution services in information-centric environment

Abstract: Information Centric Networks (ICN) enable accessing data oblivious of its location, by allowing end-systems to retrieve content based on names. But, architectures such as Named Data Networking (NDN) and Content Oriented Publish/Subscribe System (COPSS) do not yet provide a mechanism for end-system applications to obtain these names. There is a need for an object resolution system that addresses a most important and as yet unimplemented component of obtaining a name in ICN. In this paper, we propose ORICE, an architectural design for Object Resolution services in Information-Centric Environment that satisfies this need. The architecture enables intelligent resolution service by placing the service in the application layer and allows for the service diversity by separating the name space management from resolution service. Through preliminary evaluation, we show that with the help of ORICE, the states stored in the network can be dramatically reduced while ensuring complete data delivery.

Mobile cloud computing [Guest Edotorial]

Abstract: Mobile Cloud Computing refers to an infrastructure where both the data storage and the data processing occur outside of the mobile device. Mobile cloud applications move the computing power and data storage away from mobile devices and into the cloud, bringing applications and mobile computing not only to smartphone users but also to a much broader range of mobile subscribers.

sNDN: A Social-aware Named Data Framework for Cooperative Content Retrieval via D2D Communications

Abstract: In this paper, we advocate cooperative content retrieval, a novel and content-centric service paradigm via device-to-device (D2D) communications to reduce cellular traffic volume and to facilitate user wireless connectivity in mobile networks. By leveraging the Named Data Networking (NDN) principle, we propose sNDN, a social-aware NDN framework to achieve efficient cooperative content retrieval. Specifically, sNDN introduces Friendship Circle by grouping a user with her close friends of high physical proximity and content similarity. We construct NDN routing tables conditioned on Friendship Circle encounter frequency to navigate content requests and content deliveries between Friendship Circles, and leverage social properties in Friendship Circle to search for the final target as inner-Friendship Circle routing. The evaluation results demonstrate that sNDN outperforms other content retrieval schemes significantly.

AS path inference: From complex network perspective

Abstract: AS-level end-to-end paths are of great value for ISPs and a variety of network applications. Although tools like traceroute may reveal AS paths, they require the permission to access source hosts and introduce additional probing traffic, which is not feasible in many applications. In contrast, AS path inference based on BGP control plane data and AS relationship information is a more practical and cost-effective approach. However, this approach suffers from a limited accuracy and high traffic, especially when AS paths are long. In this paper, we bring a new angle to the AS path inference problem by exploiting the metrical tree-likeness or low hyperbolicity of the Internet, part of the complex network properties of the Internet. We show that such property can generate a new constraint that narrows down the searching space of possible AS paths to a much smaller size. Based on this observation, we propose two new AS path inference algorithms, namely HyperPath and Valley-free HyperPath. With intensive evaluations on AS paths from real-world BGP Routing Information Bases, we show that the proposed new algorithms can achieve superior performance, in particular, when AS paths are long paths. We demonstrate that our algorithms can significantly reduce inter-AS traffic for P2P applications with an improved AS path prediction accuracy.

VDR: A Virtual Domain-Based Routing Scheme for CCN

Abstract: In this work, we propose VDR, a routing scheme based on virtual domains -- domains that are not bound to physical routers -- to exploit the benefits of aggregation and hashing while overcoming their disadvantages. VDR addresses the FIB scalability issue in CCN by facilitating aggregation without compromising on the advantages of CCN such as ease of data replication and obtaining the data from a closer source. Our preliminary evaluation shows that VDR lowers the number of FIB entries present at a router significantly without compromising much on path stretch.

Recent Advances and Challenges in Ubiquitous Sensing.

Abstract: Ubiquitous sensing is tightly coupled with activity recognition. This survey reviews recent advances in Ubiquitous sensing and looks ahead on promising future directions. In particular, Ubiquitous sensing crosses new barriers giving us new ways to interact with the environment or to inspect our psyche. Through sensing paradigms that parasitically utilise stimuli from the noise of environmental, third-party pre-installed systems, sensing leaves the boundaries of the personal domain. Compared to previous environmental sensing approaches, these new systems mitigate high installation and placement cost by providing a robustness towards process noise. On the other hand, sensing focuses inward and attempts to capture mental activities such as cognitive load, fatigue or emotion through advances in, for instance, eye-gaze sensing systems or interpretation of body gesture or pose. This survey summarises these developments and discusses current research questions and promising future directions.

Demo abstract: Use the force, Luke: Implementation of RF-based gesture interaction on an android phone

Abstract: Various approaches exist to detect gestures and movements via smartphones. Most of them, however, require that the smartphone is carried on-body. The abscence of reliable ad-hoc on-line gesture detection from environmental sources inspired this project for on-line hand gesture detection on a smartphone using only WiFi RSSI. We highlight our line of work and explain problems at hand to provide information for possible future work. We will furthermore introduce wifiJedi, a smartphone application, that is able to detect movement in front of the smartphone by reading the WiFi RSSI and use this information to control a Slideshow.

Prototype of an Architecture for Object Resolution Services in Information-Centric Environment

Abstract: In this demo, we implemented a prototype of the our recent work ORICE -- an architecture for Object Resolution services in Information-Centric Environment that maps user inputs to Content Names. With demonstration, we show the feasibility of ORICE in fulfilling the necessity for object resolution services in ICN. We will deploy the ICN platform in our lab test bed and the front-end application will access the network through SSH tunnels.

VIRO: A virtual routing method for eliminating dead end in Opportunistic Mobile Social Network

Abstract: Opportunistic Mobile Social Networks (MSNs) as a kind of social network in which nodes are opportunistically connected. Many data routing strategies have been proposed for opportunistic MSNs. Most of them apply a utility for relay selection that a node with a higher utility value is selected as relay. However, such utility-based routing strategies run into dead end problem in which the data is stuck into a node with local maximal utility value. In this paper, we propose a virtual routing method named VIRO, which exerts conformal mapping to convert the local topology of dead end into a virtual geometric map to guarantee data dissemination to the next relay. We first convert the utility into geometric planner, and then conduct the discrete Ricci Flow bypass the gap between the dead end and next relay. Extensive experiment results suggest VIRO can reduce the ratio of dead end effectively so that the data delivery ratio is enhanced up to 42% by increasing only a slight amount of delay and cost.

SAID: A Control Protocol for Scalable and Adaptive Information Dissemination in ICN

Abstract: Information dissemination applications (video, news, social media, etc.) with large number of receivers need to be efficient but also have limited loss tolerance. The new Information-Centric Networks (ICN) paradigm offers an alternative approach for reliably delivering data by naming content and exploiting data available at any intermediate point (e.g., caches). However, receivers are often heterogeneous, with widely varying receive rates. When using existing ICN congestion control mechanisms with in-sequence delivery, a particularly thorny problem of receivers going out-of-sync results in inefficiency and unfairness with heterogeneous receivers. We argue that separating reliability from congestion control leads to more scalable, efficient and fair data dissemination, and propose SAID, a Control Protocol for Scalable and Adaptive Information Dissemination in ICN. To maximize the amount of data transmitted at the first attempt, receivers request any next packet (ANP) of a flow instead of next-in-sequence packet, independent of the provider's transmit rate. This allows providers to transmit at an application-efficient rate, without being limited by the slower receivers. SAID ensures reliable delivery to all receivers eventually, by cooperative repair, while preserving privacy without unduly trusting other receivers.