Piotr Wydrych

Cost-Driven Peer Rating Algorithm

The paper presents a concept of a rating algorithm aiming at overall peer-to-peer traffic reduction (and locality awareness) and decrease of load on costly links, thus diminishing operators costs. The rating algorithm is not only performed by a sole Oracle, as is typically proposed, but its operation is also supported by a similar entity located in other domains. Due to this concept, a usually omitted fact that the inter-domain routes are asymmetrical is properly dealt with. Simulations performed on a real topology show the usefulness of the presented approach.

Enterprise-oriented cybersecurity management

Information technology is widely used in processes vital to enterprises. Therefore, IT systems must meet at least the same level of security as required from the business processes supported by these systems. In this paper, we present a view on cybersecurity management as an enterprise-centered process, and we advocate the use of enterprise architecture in security management. Activities such as risk assessment, selection of security controls, as well as their deployment and monitoring should be carried out as a part of enterprise architecture activity. A set of useful frameworks and tools is presented and discussed.

Efficient Modelling of Traffic and Quality of Scalable Video Coding (SVC) Encoded Streams

In this letter, a new model for generating SVC-like traffic and estimating its quality is introduced. Comprising two independent components - i.e., the traffic generator and the quality estimator - the model can significantly speed up the development of SVC applications in various use-cases by relying on approximated properties of streams instead of real traces. The model is verified based on a set of video streams and the performance of its components is assessed.

Will P2P users cooperate with ISPs? A word-of-mouth communication approach

Researchers who address the problem of application-level traffic optimization often consider only the simplest comparison scenario: (a) the case before the option to cooperate and optimize the service is enabled, and (b) the case in which all clients try to optimize the traffic. In this paper, the situations that a user may not wish to cooperate or that a user does not perceive the optimization possibility to be valuable enough to cooperate are taken into account. An analytical model for estimating the popularity of the cooperate-to-optimize option is derived. A method for calculating the time-dependent value of the predicted popularity is presented. The model is verified by simulation experiments.

ISP-Supported Traffic Reduction for Application-Level Multicast

The paper proves that it is possible to optimize application-level multicast operation from the viewpoint of traffic flows. A modification of the FreePastry/Scribe application is proposed to enable cooperation with the IETF ALTO (Application- Layer Traffic Optimization) protocol. Consequently, the overlay topology is constructed taking into account the underlying network topology. The presented results show that costly traffic types can be reduced while the increase of the delay is not harmful.

Locality- and quality-awareness for P2PTV systems based on Scalable Video Coding (SVC)

In this paper, an innovative and adaptive BitTorrent-based peer-to-peer television (P2PTV) system is proposed and investigated. It is shown how end-users of such systems and Internet Service Providers (ISPs) may benefit from simultaneous usage of both (a) the recently standardized ALTO Protocol, and (b) Scalable Video Coding (SVC). The system description is followed by a thorough evaluation of the results gathered during the simulation experiments.

Book reviews [4 books reviewed]

The following books are reviewed: MIMO Communication for Cellular Networks (Huang, H. et al; 2012); Microwave and Millimeter-Wave Remote Sensing For Security Applications (Nanzer, J.; 2012); Scalability, Density, and Decision Making in Cognitive Wireless Networks (Marshall, P.; 2012); and The Art of the Data Center: A Look Inside the Worlds Most Innovative and Compelling Computing Environments (Alger, D; 2012).