Poznań, Poland
Poznań, Poland

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Gierszal H.,Adam Mickiewicz University | Sdongos E.,National Technical University of Athens | Kiedrowski L.,ITTI | Korzeniowki D.,ITTI | And 7 more authors.
International Conference on Wireless and Mobile Computing, Networking and Communications | Year: 2016

Satellite transmission based on IP may play important role for communication between event site and PPDR centers during large planned scenarios and disaster/unplanned ones. Geostationary SATCOM links that can be installed ad-hoc in any location present reliable and efficient way to transmit IP data even for voice communication based on VoIP. Using different mechanisms that handle multi connections the reliability of data exchange among PPDR agencies can be improved. The efficiency of satellite communication is reported by tests done for TCP and UDP transmission in Ka band. © 2016 IEEE.


Andersson M.,Swedish Defence Research Agency | Patino L.,University of Reading | Burghouts G.J.,TNO | Flizikowski A.,ITTI | And 5 more authors.
2013 10th IEEE International Conference on Advanced Video and Signal Based Surveillance, AVSS 2013 | Year: 2013

In this paper we present a set of activity recognition and localization algorithms that together assemble a large amount of information about activities on a parking lot. The aim is to detect and recognize events that may pose a threat to truck drivers and trucks. The algorithms perform zone-based activity learning, individual action recognition and group detection. Visual sensor data, from one camera, have been recorded for 23 realistic scenarios of different complexities. The scene is complicated and causes uncertain and false position estimates. We also present a situational assessment ontology which serves the algorithms with relevant knowledge about the observed scene (e.g. information about objects, vulnerabilities and historical data). The algorithms are tested with real tracking data and the evaluations show promising results. The accuracies are 90 % for zone-based activity learning, 71 % for individual action recognition and 66 % for group detection (i.e. merging of people). © 2013 IEEE.


Flizikowski A.,University of Technology and Life Sciences in Bydgoszcz | Majewski M.,ITTI | Przybyszewski M.,ITTI
Advances in Intelligent and Soft Computing | Year: 2011

Call admission control in access network has become an interesting topic for the research community due to its potential applicability in broadband wireless systems. Admission control problem can be formulated as Markov decision process (MDP) and has proven to deliver optimal policies for blocking and dropping probabilities in wireless networks. This however typically requires the model to know the system dynamics in advance. One approach to solving MDPs considers letting CAC agent interact with the environment and learn by "trial and error" to choose optimal actions-thus Reinforcement Learning algorithms are applied. Abstraction and generalization techniques can be used with RL algorithms to solve MDPs with large state space. In this paper authors decribe and evaluate a MDP formulated problem to find optimal Call Admission Control policies for WiMAX networks with adaptive modulation and coding. We consider two classes of service (BE and UGS-priority) and a variable capacity channel with constant error bit rate. Hierarchical Reinforcement Learning (HRL) techniques are applied to find optimal policies for multi-task CAC agent. In addition this article validates several neural network training algorithms to deliver a training algorithm suitable for the CAC agent problem. © 2011 Springer-Verlag Berlin Heidelberg.


Flizikowski A.,University of Technology and Life Sciences in Bydgoszcz | Majewski M.,ITTI | Przybyszewski M.,ITTI
2010 Future Network and Mobile Summit | Year: 2010

The authors contribute to the spectrum of quality of experience (QoE) research by defining simulation platform for evaluation of VoIP quality of experience over a wireless WiMAX link. In particular the authors show how the Matlab/Simulink and ns2 integration can be facilitated to tackle the QoE aspects in a comprehensive manner. Furthermore the process of measuring QoE using an off-line implementation of the ITU-T E-model is presented and applied to the results of the QoS test campaign. Simulations are performed with the use of robust nb-LDPC coding scheme, which is current research topic in the FP7 DaVinci project. The obtained results of QoE over WiMAX are later compared to the results for Red-Solomon Convolutional Codes. Copyright © 2010 The authors.


Gierszal H.,Adam Mickiewicz University | Holubowicz W.,Adam Mickiewicz University | Kiedrowski L.,ITTI | Flizikowski A.,University of Technology and Life Sciences in Bydgoszcz
International Journal of Electronics and Telecommunications | Year: 2010

A new family of non-binary LDPC is presented that are based on a finite field GF(64). They may be successfully implemented in single-carrier and OFDM transmission system. Results prove that DAVINCI codes allow for improving the system performance and may be considered to be applied in the future mobile system.


Flizikowski A.,University of Technology and Life Sciences in Bydgoszcz | Majewski M.,ITTI | Puchalski D.,ITTI | Hassnaa M.,Orange Group | Choras M.,University of Technology and Life Sciences in Bydgoszcz
Advances in Intelligent Systems and Computing | Year: 2013

Mobile technologies, new interactive applications and the service providers' customer-centric approach are influencing the way of assessing QoE nowadays. Traditional QoE assessment methods proved to be effective when dealing with legacy audio/video services; however, current IPTV services provide features beyond traditional TV and are not limited to delivering audiovisual content but may also rely on auxiliary services (e.g. content recommendation). Personalization mechanisms that learn instantaneous user-context relation are interesting extension of the QoE parameters enabling improved experience customization. This paper is focused on the QoE-context relation for context-aware IPTV platforms offering personalized TV experience. The latter systems are in the scope of the UP-TO-US project which is treated in this paper as a reference project dealing with user experience and IPTV. Authors define a QoE architecture for validating traditional subjective assessment methodologies (e.g. based on human visual system modeling, or standardized methodologies like ITU-T BT.500-11) by adopting additional context characteristics - user emotions. Moreover the proposed QoE module is aligned with the architecture defined in the UP-TO-US. In the proposed approach to affective QoE authors foresee important role for learning algorithms that can be applied in order to build a user model (an agent reasoning on QoE based on the gathered knowledge about user-content relation). © 2013 Springer-Verlag.


Gierszal H.,Adam Mickiewicz University | Stachowicz A.,ITTI | Majerowski F.,ITTI | Kowalczyk B.,ITTI | And 3 more authors.
2014 Federated Conference on Computer Science and Information Systems, FedCSIS 2014 | Year: 2014

The paper presents requirements related to a heterogeneous interoperable and transportable gateway called HitGW that is designated to connect different incompatible communication systems used by First-Responders (FRs) and to make them interoperable with IP-based networks. The HitGW allows IMS type of services and applications over a broadband network composed of ordinary Public Protection and Disaster Relief (PPDR) networks and Commercial Communication Networks (CCNs). Such a system solution for FRs becomes indispensable for interoperable, effective, secure, and safety communications especially in national and cross-border crisis scenarios. The innovativeness in the chosen approach to design and implement such a system gateway primary consists in the user needs and current trends of PPDR networks toward 4G LTE type of networks and services. © 2014 Polish Information Processing Society.


Krenz R.,Poznan University of Technology | Brahma S.,ITTI
2015 IEEE International Black Sea Conference on Communications and Networking, BlackSeaCom 2015 | Year: 2015

In a majority of European countries a digital trunking TETRA system is used for Public Safety communication. This system offer voice communication and narrowband data services only. Since the introduction of first LTE commercial networks, LTE is rapidly gaining momentum within the Public Safety industry as well. Therefore it is important to verify the immunity of the system, originally designed for civil applications, to intentional jamming. In this paper some potential ways of attacks are discussed and an easy-to-implement method is analyzed in details. The results suggest that jamming LTE signals is relatively easy and can be done using low cost off-the-shelf equipment. © 2015 IEEE.


Holubowicz W.,Adam Mickiewicz University | Kiedrowski L.,ITTI | Romanowski K.,ITTI
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2011

The demonstration presents a simulation tool developed in the N4C project. The project involved development, integration, and deployment of delay-tolerant networks (DTN) and applications in remote areas. The simulation tool supports system integration and testing by connecting real and virtual hardware and software network nodes via DTNs simulated with the aid of the ns-3 network simulator. The examples shown illustrate node discovery and message transport - direct as well as using a data mule service. © 2011 Springer-Verlag.


In this paper, methods for increasing security of interconnection between telecommunication network and SCADA (Supervisory Control and Data Acquisition) systems are presented. Development and evolution of SCADA systems imply the need to ensure security, reliability and quality of service. It is very important for proper functioning of power grids, which are monitored and controlled by SCADA systems. INSPIRE project (Increasing Security and Protection through Infrastructure Resilience), conducted as a 7 Framework Program project European Union faces up SCADA systems requirements and proposes new mechanisms to provide security, resilience and quality of service. The proposed techniques and mechanisms are P2P technology and MPLS. New methods of monitoring, diagnosis and reaction are developed. Moreover offline decision support system called Decision-Aid Tool (DAT) has been created. Its operation is based on data from SCADA systems security ontology. Since SCADA systems are widely used to supervise the power grids, results of INSPIRE project are important for increasing power grids security and resiliency.

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