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Poznań, Poland

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.

Grazia C.A.,University of Modena and Reggio Emilia | Klapez M.,University of Modena and Reggio Emilia | Patriciello N.,University of Modena and Reggio Emilia | Casoni M.,University of Modena and Reggio Emilia | And 10 more authors.
International Conference on Wireless and Mobile Computing, Networking and Communications | Year: 2014

Wireless communication technologies are critical for public protection and disaster relief (PPDR) professionals during the emergency operations that follow natural or man-made disasters, scenarios in which commercial terrestrial networks often fail to provide the necessary support. The reason is threefold: they simply get disrupted by the disaster, they cannot sustain the sudden surge of network demand or they fail to deliver the necessary bandwidth and/or other QoS guarantees. In every PPDR operation reliable voice communications are critical, especially in the very early stages of the response; nevertheless, there is an increasing demand from the PPDR community for a wider range of data-centric services. While current technologies used for PPDR operations provide a rich set of voice-centric services, they are unable to sustain high-bandwidth data-oriented applications. As the PPDR-TC EU consortium, we propose a hybrid approach to tackle the question of determining the future architecture for Pan-European PPDR networks based on the integration of Terrestrial and Satellite technologies, presenting our first simulation results on the integration of LTE and Satellite Networks. © 2014 IEEE.

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 | 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.

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.

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