The Internet has led to the creation of a digital society, where (almost) everything is connected and is accessible from anywhere. However, despite their widespread adoption, traditional IP networks are complex and very hard to manage. It is both difficult to configure the network according to predefined policies, and to reconfigure it to respond to faults, load, and changes. To make matters even more difficult, current networks are also vertically integrated: the control and data planes are bundled together. Software-defined networking (SDN) is an emerging paradigm that promises to change this state of affairs, by breaking vertical integration, separating the network's control logic from the underlying routers and switches, promoting (logical) centralization of network control, and introducing the ability to program the network. The separation of concerns, introduced between the definition of network policies, their implementation in switching hardware, and the forwarding of traffic, is key to the desired flexibility: by breaking the network control problem into tractable pieces, SDN makes it easier to create and introduce new abstractions in networking, simplifying network management and facilitating network evolution. In this paper, we present a comprehensive survey on SDN. We start by introducing the motivation for SDN, explain its main concepts and how it differs from traditional networking, its roots, and the standardization activities regarding this novel paradigm. Next, we present the key building blocks of an SDN infrastructure using a bottom-up, layered approach. We provide an in-depth analysis of the hardware infrastructure, southbound and northbound application programming interfaces (APIs), network virtualization layers, network operating systems (SDN controllers), network programming languages, and network applications. We also look at cross-layer problems such as debugging and troubleshooting. In an effort to anticipate the future evolution of this new paradigm, we discuss the main ongoing research efforts and challenges of SDN. In particular, we address the design of switches and control platforms—with a focus on aspects such as resiliency, scalability, performance, security, and dependability—as well as new opportunities for carrier transport networks and cloud providers. Last but not least, we analyze the position of SDN as a key enabler of a software-defined environment.

https://publications.uni.lu/bitstream/10993/20596/1/survey_on_SDN.pdf

Software-Defined Networking: A Comprehensive Survey

Network use has evolved to be dominated by content distribution and retrieval, while networking technology still speaks only of connections between hosts. Accessing content and services requires mapping from the what that users care about to the network's where. We present Content-Centric Networking (CCN) which treats content as a primitive - decoupling location from identity, security and access, and retrieving content by name. Using new approaches to routing named content, derived heavily from IP, we can simultaneously achieve scalability, security and performance. We implemented our architecture's basic features and demonstrate resilience and performance with secure file downloads and VoIP calls.

/pdf/networking-named-content-ymua8rkdmw.pdf

Networking named content

Current network use is dominated by content distribution and retrieval yet current networking protocols are designed for conversations between hosts. Accessing content and services requires mapping from the what that users care about to the network's where. We present Content-Centric Networking (CCN) which uses content chunks as a primitive---decoupling location from identity, security and access, and retrieving chunks of content by name. Using new approaches to routing named content, derived from IP, CCN simultaneously achieves scalability, security, and performance. We describe our implementation of the architecture's basic features and demonstrate its performance and resilience with secure file downloads and VoIP calls.

Together with an explosive growth of the mobile applications and emerging of cloud computing concept, mobile cloud computing (MCC) has been introduced to be a potential technology for mobile services. MCC integrates the cloud computing into the mobile environment and overcomes obstacles related to the performance (e.g., battery life, storage, and bandwidth), environment (e.g., heterogeneity, scalability, and availability), and security (e.g., reliability and privacy) discussed in mobile computing. This paper gives a survey of MCC, which helps general readers have an overview of the MCC including the definition, architecture, and applications. The issues, existing solutions, and approaches are presented. In addition, the future research directions of MCC are discussed. Copyright © 2011 John Wiley & Sons, Ltd.

A survey of mobile cloud computing: architecture, applications, and approaches

Matrix Factorization Techniques for Recommender Systems

Differential privacy allows quantifying privacy loss resulting from accessing sensitive personal data. Repeated accesses to underlying data incur increasing loss. Releasing data as privacy-preserving synthetic data would avoid this limitation, but would leave open the problem of designing what kind of synthetic data. We propose formulating the problem of private data release through probabilistic modelling. This approach transforms the problem of designing the synthetic data into choosing a model for the data, allowing also including prior knowledge, which improves the quality of the synthetic data. We demonstrate empirically, in an epidemiological study, that statistical discoveries can be reliably reproduced from the synthetic data. We expect the method to have broad use in creating high-quality anonymized data twins of key data sets for research.

Privacy-preserving data sharing via probabilistic modelling

In this paper, we formally define a useful data structure for content-based routing and event delivery. The poset (partially ordered set)-derived forest data structure is induced by the partial order created by the covering relation between event filters. Two extensions of the basic data structure are discussed: colored forests and the weakly merging forest. We give performance figures for the data structure using a workload generator and compare it with the filters poset structure. The experimental results indicate that the poset-derived forest performs considerably better than directed acyclic graph-based structures. The presented algorithms and mechanisms generalize to any covering relations and are thus applicable for different filtering languages.

A Data Structure for Content-based Routing.

The popularity of touch-screen-equipped smart phones has made them an attractive choice for interacting with large display surfaces, especially in public spaces. The challenge in using a personal mobile device for interaction in such a setting lies in the usability of methods to initiate the interaction, as the users may give up if the interaction is not immediately successful. For this reason, a few commercial systems have already opted to use web-based interaction instead of dedicated mobile applications. However, the usability of different methods of initiating the web-based interaction has not been extensively studied. In this paper we present the results of a laboratory usability study with 20 participants, in which we studied how the users experienced four different methods of initiating web-based interaction between a smart phone and a large display surface. The compared initiation methods were NFC, QR code, typing an URL and connecting to a WiFi access point. Additionally, in order to study how the users experienced the quality of the connection, the first three methods were used over 3G. Our results indicate typing an URL to be the most usable method for initiating the connection between the smart phone and the large display surface. The difference in quality between the 3G and WiFi connections was deemed hardly noticeable by the subjects. We acknowledge that our results are only preliminary, and the subject needs to be studied in a more realistic setting to get a more comprehensive picture.

Personal Device as a Controller for Interactive Surfaces: Usability and Utility of Different Connection Methods

Pervasive availability of programmable smart de-vices is giving rise to sensing and computing scenarios that involve collaboration between multiple devices. Maximizing the benefits of collaboration requires careful selection of devices with whom to collaborate as otherwise collaboration may be interrupted prematurely or be sub-optimal for the characteristics of the task at hand. Existing research on collaborative scenarios has mostly focused on providing mechanisms that can establish and harness collaboration, without considering how to maximally benefit from it. In this paper, we contribute by developing COSINE as a novel approach for selecting collaborators in multi-device computing scenarios. COSINE identifies and recommends collaborators based on a novel information theoretic measure based on Markov trajectory entropy. Rigorous experimental benchmarks carried out using a large-scale dataset of device-to-device encounters demonstrate that COSINE can significantly improve collaboration benefits compared to current state-of-the-art solutions, increasing expected duration of collaboration and reducing variability of collaborations.

/pdf/cosine-collaborator-selector-for-cooperative-multi-device-13ywjth6cc.pdf

COSINE: Collaborator Selector for Cooperative Multi-Device Sensing and Computing

Location information is provided with an authenticator in order to enable future providing of an authentication to a service or application making use of the location information. The authenticator is based on a cryptographic method known by a provider and recipient of and also optionally based on position data provided by the location information. The authenticator is carried as a watermark in the location information so that the location information can be used by prior existing systems and enables the authentication of the location information in compatible authentication enabled systems. On receiving the location information, an authentication enabled recipient obtains the authenticator from the location information and checks using the authenticator whether use of the location information may be allowed.

Sasu Tarkoma

Papers

Privacy-preserving data sharing via probabilistic modelling

A Data Structure for Content-based Routing.

Personal Device as a Controller for Interactive Surfaces: Usability and Utility of Different Connection Methods

COSINE: Collaborator Selector for Cooperative Multi-Device Sensing and Computing

Location information verification