The popularity of unmanned vehicles in numerous areas of employment, combined with the diversity and continuing evolution of their payloads, make the communication solutions utilized by such vehicles the element of a particular importance. In our previous publication, we confirmed a general applicability of wireless local area network (WLAN) technologies as solutions suitable to provide a control loop communication of unmanned surface vehicles (USVs). At the same time, our research indicated that WLAN technologies provide communication resources in excess of what is required for the above task. In this paper, we aim to verify if a WLAN-based USV communication solution can be reliably utilized for both time-sensitive control loop and high-throughput payload communication simultaneously, which could provide significant advantages during USV construction and operation. For this purpose, we analyzed traffic parameters of popular USV payloads, designed a test system to monitor the impact of such traffic sharing a WLAN link with a USV control loop communication and conducted laboratory and field experiments. As initial results indicated the significant impact of payload traffic on the quality of control communication, we have also proposed a method of employing Commercial Off The Shelf (COTS) hardware for this purpose, in a manner which allows the above-mentioned link sharing to operate reliably in changing real-world conditions. The subsequent verification, first in the laboratory and then during a real-world USV field deployment, confirmed the effectiveness of the proposed method.

The evolution of the 5 G and future 6 G networks into a virtualized infrastructure enables the deployment of virtual firewalls (vFW) to protect the network from undesirable traffic and other threats. The main advantages of the vFW systems come from the flexible deployment of vFW instances across the Telco Cloud-Edge Continuum (TCE) infrastructure and from horizontal scaling of vFW to accommodate daily changes in traffic demand. We propose a new virtual Firewall Allocation and Traffic Distribution (vFATD) approach to orchestrate the vFW system. We formulate the vFATD problem, design a MILP-based optimum orchestration algorithm, and propose k-center-based and genetic-evolution-based heuristic algorithms for practical use. Comprehensive experiments based on actual network topologies and traffic data from a mobile network operator confirmed that the proposed vFATD approach significantly outperforms the current approaches. The results say that the main gain comes from engaging traffic distribution that: i) reduces the vFW system costs by optimizing used computing and network resources, ii) improves its robustness against unexpected traffic changes, e.g., during DDoS attacks, and iii) relaxes the need for precise vFW provisioning as its performance is continuously adapted to actual traffic demands.

The evolution of the $\mathbf{5 G}$ systems into a virtualized infrastructure enables the deployment of virtual firewalls (vFW) to protect the system from undesirable traffic and other threats. The current orchestration algorithms usually provision vFW instances at network edges. We propose a new virtual Firewall Allocation and Traffic Distribution (vFATD) approach that flexibly allocates and scales vFW instances over the distributed edge-cloud continuum infrastructure to reduce the overall vFW system costs. We designed and evaluated the MILP-based exact and k-center-based heuristic orchestration algorithms. The experiments performed using actual data traffic from a mobile network operator confirm that the proposed vFATD algorithms are reasonable and may bring network providers significant gains.

The paper focuses on future 6G mobile systems deployed over the edge-cloud continuum infrastructure. The challenge is designing an effective orchestration method that allocates instances of edge applications and user plane functions, addressing the diverse requirements of involved stakeholders. We propose, implement, and evaluate new joint orchestration algorithms that take advantage of the abstract representation of edge-cloud continuum resources. The evaluation based on mathematical MILP models and trials in an experimental edgecloud continuum environment confirmed that the proposed joint orchestration outperforms other approaches.

This paper shortly describes the IP QoS System which offers strict quality of service (QoS) guarantees in IP-based networks and supports a number of, so called, classes of services. Such solution requires to implement in the network a set of QoS mechanisms and algorithm working on packet, connection request and provisioning levels. Furthermore, we require signaling system for informing the network about new connection request and network resource allocation capabilities for providing required resources to given connection. The IP QoS System is based on the next generation networks (NGN) and differentiated services (DiffServ) architectures and, at least for now, it is designed for single domain only.

Wydawnictwo SIGMA-NOT wydaje czasopisma fachowe informujące swoich czytelników o najnowszych osiągnięciach naukowych i nowoczesnych rozwiązaniach technicznych w Polsce i na świecie, popularyzuje problemy techniczne oraz poszerza wiedzę i kulturę techniczną.

Software upgrades, reconfiguration, and deployment of new services happen so frequently in the carrier-grade VNF-based networks that operators need automated orchestration and change management systems. The current approaches deal independently with each service and concentrate mainly on resource allocation or optimization of the change execution processes. We propose a new Joint Resource Allocation and Scheduling (JRAS) approach, where the orchestrator manages changes, addressing the diverse requirements and dependencies of all services together. These features result in significant gain achieved by JRAS compared to other approaches, as shown by the performed numerical analysis.

The Bluetooth Low Energy (BLE) MESH network technology gains popularity in low duty IoT systems. Its advantage is a low energy consumption that enables long lifetime of IoT systems. The paper proposes and evaluates new MRT management methods, i.e. exact and heuristic, that improves energy efficiency of BLE MESH network by minimizing the number of active relay nodes. The performed experiments confirm efficiency of the MRT methods resulting in significantly lower energy consumption of BLE MESH network.

The paper proposes provisioning methods for VoD service providers offering adaptive video streaming in a cloud environment. Our methods minimize costs paid by VoD provider thanks to rational use of on the fly video transcoding service which eliminates storage cost of rarely requested video profiles. In the paper, we formulate provisioning problem, propose optimization and heuristic methods that determine the best tradeoff between content storage and transcoding. The results of performance evaluation confirmed that proposed methods can significantly reduce costs paid by VoD providers.

Traditionally, video adaptive algorithms aim to select the representation that better fits to the current download rate. In recent years, a number of new approaches appeared that take into account the buffer occupancy and the probability of video rebuffering as important indicators of the representation to be selected. We propose an optimization of the existing algorithm based on rebuffering probability and argue that the algorithm should avoid the situations when the client buffer is full and the download is stopped, since these situations decrease the efficiency of the algorithm. Reducing full buffer states does not increase the rebuffering probability thanks to a clever management of the client buffer, which analyses the buffer occupancy and downloads higher bitrate representations only in the case of high buffer occupancy.

Currently exploited adaptive video streaming algorithms mainly focus on maximizing video representation while they usually not assess the risk of video freezing and not care about the influence of video representation switching. We propose a new Adaptation & Buffer Management Algorithm, called ABMA+, which selects video representation based on the predicted probability of video freezing. The algorithm continuously estimates segment download time characteristics and use the pre-computed playout buffer map to select the maximum video representation which guarantee smooth content playout. Our algorithm, thanks to the buffer map, avoids heavy online computation so it could be widely deployed on different terminals. The performed simulation and trial experiments confirm the efficiency of our approach.

New trends of the future Internet aim to overcome the best effort service and offer guaranteed service to the users. Guarantees should be acquired not only at the network level but also at higher layers in order to deliver the best quality of experience. This paper presents a new approach for HTTP-compliant adaptive applications. This solution fulfills the guarantees of maximum rebuffering probability even in highly variable environments as the future Internet seems to be. Guaranteed low rebuffering improves visibly the user's quality of experience during multimedia events. The tests performed confirmed that, unlike rate-based adaptation algorithms, our solution ensures maximum rebuffering and it decisively reduces rate switches in comparison with buffer-based adaptation algorithms.

The increasing popularity of Internet of Things (IoT) services causes tremendous growth of the amount of produced data. These data must be effectively stored and retrieved by the IoT service providers. The solution is to access the data through application programming interfaces. The paper focuses on the problem of designing an effective data storage service for IoT, which will be available through the universal application programming interface. We propose and analyze eight variants of the distributed data storage service that differ in the database structure, that is, the hierarchical structure based on Data-Oriented Network Architecture or the flat structure based on distributed hash table, the type of stored records, and the memory management algorithm that decides about using cache or base memory. The proposed solutions have been evaluated in the comprehensive simulation studies. The obtained results confirmed the effectiveness of the preferred solution with Dynamic Routing Records stored in the cache memory. Copyright (C) 2016 John Wiley & Sons, Ltd.

Information Centric Networks (ICN) enable network, server context and user context-awareness, to achieve an enhanced architecture for the delivery of the multimedia content. The information comes from different sources and serves as input for the decision algorithms for choosing the pertinent configuration such as the best server or the suitable delivery path. Therefore, the relevance of the input information and the efficiency of the decision algorithms are both crucial for the system performance. This paper proposes exploiting the multi-criteria optimization algorithms in the context of the ICN. Based on the approach of the reference level decision, an optimized algorithm is proposed, which considers the impact of different network and server parameters, and dynamically adapts the decision to the current state of the system. The additional contribution of the paper is comprehensive video content consumption simulation model, which represents large scale network. This model was designed to compare effectiveness of decision algorithms proposed for ICN. The presented simulation results prove effectiveness of proposed decision algorithm and suggest its deployment on the future media networks.

Przedstawiono infrastrukture sieci badawczej PL-LAB2020. Zaprezentowano 7 laboratoriow badawczych PL-LAB umozliwiających prowadzenie badan w glownych ich obszarach zdefiniowanych dla programu Horyzont 2020. Przedstawiono szczegoly struktury operacyjnej PL-LAB2020 lączącej zasoby poszczegolnych laboratoriow zlokalizowane w 6 ośrodkach naukowo-badawczych w jedno rozproszone środowisko badawcze. Ostatecznie pokazano, jak infrastruktura PL-LAB2020 zostala polączona z innymi sieciami badawczymi w Europie.