Piotr Gajewski

• Professor (Full) at Military University of Technology

The problem of waveform construction for mobile ad hoc networks with cognitive radio (MANET-CR) is discussed. This is the main limitation to widely use this very attractive technique, which does not need the deployment of expensive communication infrastructure. Two main questions correspond to MANET-CR effectiveness: spectrum sensing and spectrum s...

Radio environment maps (REMs) are beginning to be an integral part of modern mobile radiocommunication systems and networks, especially for ad-hoc, cognitive, and dynamic spectrum access networks. The REMs will use emerging military systems of tactical communications. The REM is a kind of database used at the stage of planning and management of the...

The Authors present a new approach to a method of dynamic spectrum management within military mobile ad hoc network. They propose that data concerning tactical radio operator’s combat readiness be used as context information for spectrum management. The readiness is determined based on monitored vital signs of and interaction with the tactical radi...

INTRODUCTION: The Authors present a new approach to a method of dynamic spectrum management for militarymobile ad hoc network. They propose that data concerning vital signs of tactical radio operators be used as contextinformation for spectrum management. If the operator’s inability to operate and protect the tactical radio is identified,actions (r...

The rapid development of systems using wireless technologies causes increasing problem of spectrum shortage. That is why a concept of dynamic access to the spectrum (DSA) has appeared. The most advanced form of DSA is the opportunistic access (OSA), which will find its implementation in the future solution of the cognitive radio. Nowadays, the rati...

Efficient Dynamic Spectrum Management balances the energy consumption problem, eliminates conflicts between the nodes, reduces the channel interference, divides the traffics over different channels and time slots. In this paper, we propose a new channel management algorithm for Cognitive Radio Sensor Networks, which heightens the energy efficiency...

This paper describes the idea of quality enhancements in the OLSRv2, one of the most popular and standardized proactive routing protocol for mobile ad-hoc networks (MANET). Proposed method calculates link metric value with respect to the link quality parameters like link delay, error rate and other state and time related link parameters. These para...

This paper deals with requirements related to the possibilities and limitations of using the commercial-off-the-shelf IPv6 components in tactical communications and information systems. It describes the requirements based on military communications network needs analyses. "NATO C3 Technical architecture" by NATO C3 Board Information Systems Sub-com...

Mobile Ad-Hoc networks (MANET) are widely used for data communication between mobile nodes on the digital battlefield. Clustering has evolved as an important research topic in military MANETs in reference to supporting the ability of C4I system reconfiguration in highly dynamic operation. Clustering is a process that divides the network nodes into...

Cognitive Radio (CR) usually performs an analysis of the existing environment, enabling collection of all information on current spectrum use and available resources, to decide on its own transmission parameters to optimize communication performance. From practical point of view, the principal task of spectrum sensing is an efficient detection of d...

The paper is devoted to the question of locating of radio wave emission sources by using of SDF technology. The generalized algorithm to estimate the radio transmitter coordinates has been presented. The Doppler characteristics are the basis to determine the location coordinates of a source. They are obtained as the result of measuring of instantan...

The paper is devoted to the question of locating of radio wave emission sources by using of SDF technology. The generalized algorithm to estimate the radio transmitter coordinates has been presented. The Doppler characteristics are the basis to determine the location coordinates of a source. They are obtained as the result of measuring of instantan...

The paper is devoted to the question of locating of radio wave emission sources by using of SDF technology. The generalized algorithm to estimate the radio transmitter coordinates has been presented. The Doppler characteristics are the basis to determine the location coordinates of a source. They are obtained as the result of measuring of instantan...

The paper is devoted to the question of locating of radio wave emission sources by using of SDF technology. The generalized algorithm to estimate the radio transmitter coordinates has been presented. The Doppler characteristics are the basis to determine the location coordinates of a source. They are obtained as the result of measuring of instantan...

The paper is devoted to the subject of simultaneous location of many radio waves emitting sources. The possibility to use the SDF method based on the Doppler effect and spectral analysis of signals received have been presented in it. The evaluation of the location procedure accuracy and time of realisation has been done according to simulation test...

The analysis of the literature shows that there is lack of attenuation prediction models in the urban environment for frequencies the most often exploited in military communication systems and for geometries of these systems (low hanged antennas). The only model that however require additional experimental verification is the one published in [5]....

Increasing demands are being placed on dynamic spectrum access as a result of overload of the frequency spectrum. In this paper we present a concept of frequency broker as a crucial element of coordinated spectrum management system for battlefield communication network. Critical problem in such system is automation of the collision-free frequency p...

The paper describes the method that enables to measure acoustic fidelity of audio Signals degraded with digital watermarks. Fidelity measurements of degraded acoustic Signals is suitable for such applications as distinguishing whether the acoustic record is signed with a digital watermark (watermarked) or not as well as evaluation of the degradatio...

This paper presents a location method of radio emission source, which is called Signal Doppler Frequency (SDF) or Doppler location method. The method is based on applied Doppler effect, including especially functional dependence defining variations of actual values of the received signal frequency as a function of coordinates’ changes for the measu...

Prezentowana w artykule problematyka poświęcona jest dopplerowskiej metodzie lokalizacji źródeł fal radiowych, nazywanej także metodą SDF. Podstawę metody stanowi wykorzystanie efektu Dopplera, a w szczególności funkcyjna zależność opisująca zmiany częstotliwości Dopplera sygnału w funkcji zmian współrzędnych sta-nowiska pomiarowego względem lokali...

For up-to-date commercial short-distance communication systems, e.g. RF systems of VHF bandwidth or WiFi wireless networks, the development of efficient and reliable algorithms and procedures for management of the radio network subscriber identity is becoming still more important and urgent need. The existing systems for that purpose are limited to...

The paper describes the method intended to au-thenticate identity of a VoIP subscriber with use of the data hiding technique that is specifically implemented by means of the echo hiding method. The scope includes presentation of experimental results related to transmission of information via a hidden channel with use of the SIP/SDP signalling pro-t...

The paper presents the results of implementation in the Matlab environment for watermarking embedder and extractor based on the Direct Sequence Spread Spectrum (DSSS). A block diagram of watermarking system, an analysis of watermarked signal reproduced as well as watermarking system robustness to degrading factors: lossy compression, signal-to-nois...

This paper focuses on performance evaluation to study the effects of the resource management strategy in ad hoc networks. The presented strategy is a result of the new outlook on the IEEE 802.11 networks capabilities and performance enhancement. The proposed solution is dedicated to real-time services support and is based on the concept of the Reso...

The paper presents a new mechanism of hidden and secure data transmission in wireless IEEE 802.11 networks in military applications. The mechanism allows us to switch WLANs from infrastructure to the ad-hoc mode simultaneously changing transmission channels and scrambling fragmented data in the MAC layer. Optionally, we can take advantage of extra...

Artykuł poświęcony jest problematyce wpływu długości oraz położenia odcinka pomiarowego na dokładność lokalizacji źródła sygnału radiowego przy wykorzystaniu metody dopplerowskiej (SDF). Przedstawiono opis wykorzystania metody widmowej do wyznaczania wartości chwilowej częstotliwości odbieranego sygnału. Ocenę efektywności opracowanej metody dokona...

This paper deals with the new location method of radio wave sources, based on the Doppler effect. In this method, position of the radio signal source is calculated on the basis of momentary frequency measurements taken by mobile receiver. Theoretical and simulating analysis of the presented methodology was made before empirical verification process...

This paper refers to the technology of the acoustic watermark Internet server, which distributes digital sound together with additional inaudible hidden data. We describe the main architecture of this server (software modules) as well as the main features of this system. The characteristic specification referring to the implemented watermarking ser...

The objective of this study is to test and optimize the design of a 16-element antenna array made up of radiating elements in the form of Tapered Slots Antenna (TSA). Optimization of array construction and results of measurement of radiating characteristic of antenna is presented in the paper. The results from the needs to develop broadband antenna...

The paper presents some most important design issues of antennas with modelled monopulse radiation pattern in both azimuth and elevation, especially of dielectric substrate microstripe antenna structures. An approach to optimisation of the antenna patterns is discussed and an example of circular antenna array solution is presented. The issue of fee...

Our aim is to develop the method of location subscriber to be used in military communication nets. This method is based on frequency offset measurement. Analytic description of the Doppler effect creates one of such possibilities. In this paper, an original location subscriber method is presented. We showed the Maxwell equations solution in the cas...

In this paper we present algorithm and hardware architecture of the new military communication device dedicated for VHF battlefield radio stations. The results of the compatibility tests carried out for this device according to the norm MIL-STD-461D are also presented together with the figures and comments. Measurements were carried out at the Elec...

Voice spoofing carry out in the telecommunications links is potentially one of the very dangerous and destructive attacks. This kind of attack is not such popular as the Caller identification spoofing attack, mainly because it required more advanced processing than simulation or changing Caller ID number. We present hypothetical type of the voice s...

Drift Scanner Method is very effective procedure used to reduce the phase drift effect in the radio links. The effect "out of tuned" signal in the basic frequency band is a result of small, long term stability codec's clocks both at the transmitter and receiver's side as well as small stability of HF or VHF carrier frequency in the standard modulat...

The problem of radio signal sources location is one of the directions of service range development in communication nets. An original methodology of the electromagnetic waves radiation sources position co-ordinates marking is presented in this paper. This method makes use of the measurement of the actual value received through moving receiver signa...

Modern watermarking systems operating on an acoustic layer of the host signal must meet a lot of constructional requirements. One of these requirements is watermark perceptual transparency at host signal presence and robustness to intentional and unintentional attacks. Developed systems also possess a dedicated bit rate for the steganographic mode...

Modern wireless network requires often use of a wideband antenna system. Here, the tapered slot antenna (TSA) is discussed to solve the problem of optimal solution taking into account parameters of antenna and its cost and easy construction. The short TSA without dielectric is proposed as an element of antennas array in frequency range above 2.4 GH...

We proposed an OFDM and watermarking based technology system for correspondent identity verifica-tion (CIVS) in military telecommunication digital channels. Correspondent personal identity signature (CPIS) is repre-sented by digital watermark. The main idea of this system solution is to verify the end user who sends acoustic signal, e.g., speech, m...

This paper describes conception of the correspondent authorization in the GSM link. Watermarking technology gives support for additional data hiding in the host signal. This additional data is known as a watermark signal. Watermark should be robust for loose compression in GSM 6.10 standard codec and should be transparent for human auditory system...

In this paper we proposed OFDM-based technology system for correspondent verification in telecommunication digital channels. The watermarking technology can be used for hiding secret digital signature in original signal. We proposed system based on psychoacoustic correction and OFDM technology using secret signature for sender detection.

Paper presents a novel modulation that can be used for short packet transmission in the HF channel with high reliability and small delay The results of simulation studies of our quantized MFSK show the significant advantage of this modulation over the classical modulation methods most frequently used in HF systems for the data transmission. There i...

W referacie krótko scharakteryzowano problematykę planowania rozmieszczenia stacji bazowych w systemach drugiej (np. GSM) i trzeciej generacji (np. UMTS). Następnie zaproponowano rozwiązanie wspomagające prace projektowania sieci mające na celu zapewnienie możliwie największego pokrycia rozpatrywanego terenu, przy minimalnej liczbie stacji radiokom...

This paper describes a new method of frequency offset correction to improve clock stability in communication systems where the temporary drift or jitter of phase angle is not accepted. This method bases on coherent spectral averag-ing with a special phase scanning algorithm. Achieved results show that proposed method is effective for strongly degra...

This paper presents a concept of a testbed designed for laboratory and field tests of wireless communication equipment and systems. The paper presents also a proposal of its use for evaluation of Quality of Service for defined particular scenarios. One of the testbed elements is a software defined arbitrary generator, that enables generation of bot...

The TD-CDMA technique is one of the modes assumed to use in 3G UMTS networks. The synchronization error influence on the interference level is discussed for TD-CDMA mode. The simulation model for method validation is described as well as the simulation results are also presented in this paper.

The radio-resources management (RRM) in future CDMA networks is discussed taking into account the variety of services classes in 3G/4G systems. An optimising algorithm to control of data streams in up-link is described. The required signal-to-interference ratio is a criterion used in this algorithm. For this criterion, a method of interference esti...

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First Page of the Article

An original hybrid method of channels assign-ment for DS-CDMA system is discussed in the paper. This method combines standard PN codes assignment policy and dynamic channel assignment procedure that minimise the cost of channel assignment. OPNET simulation model DS-CDMA system was used for assessment of the hybrid method. The re-sults of simulation...

The electromagnetic environment is made up of signals emitted by mobile and stationary radio stations in radio communications networks, transmitting stations in the radiolinie system as well as radar, navigation, jamming and other systems to be found in a given area. Formulas for coverage and minimum distance analysis, taking into account mutual or...

The paper presents the result of CDMA network modelling using OPNET software. Some results of our model investigation are also described here. Simulation result can be achieved using elaborated computer programs or commercial software tools. OPNET (Optimized Network Engineering Tool) is an example of such commercial software elaborated and delivere...

This paper describes a model of a system with wideband CDMA that is a proposal of user access for fu-ture UMTS. This model has been implemented using OPNET tool. The model enables network architecture, radio interface, mobile station motion, call generation, signalling, etc. The ex-amples of simulation results of call and handover blocking probabil...

Wideband CDMA method has been recently in-vestigated for its using in the future communication systems. Such systems capacity depends on many factors, the main is multi-access interference (MAI). MAI is an inherent CDMA property connected to correlation characteristics of codes used to access and to spreading. The influence on CDMA perfor-mance of...

Many channels assignment procedures and allocation strategies for cellular network have been discussed for various multi-access methods. The channel allocation both for new calls and for handovered ones should minimise the co-channel interference. In CDMA, channels are creating by spreading and accessing codes. The signal-to-noise ratio (SNR) is ge...

This paper presents tests results of long distance HF link and structure of used radio workstations for e-mail exchange, analog and digital voice transmission. Tests results are: average transmission time for short and long messages and percentage ratio of speech intelligibility for different speech transmission modes

This paper describes a model of a system with wideband CDMA that is a proposal for user access in the future UMTS. This model has been implemented using the OPNET tool. The model enables network architecture, radio interface, mobile station moving, call generation, signalling, etc. to be considered. The interference is discussed for two approaches:...

This paper describes performance of DS-CDMA system, which uses a soft handover method and a dynamic channel allocation policy. The considered system uses the same spectrum band in the system area. Assuming that there is a limited number of logical channels in the system, we can use an approach similar to a standard narrowband system and allocate ch...

The general concept of methodology of military CIS interoperability modelling is presented. Special attention is focused on the procedure of CIS interoperability examination. The idea of the procedure is derived from taxonomic methods. It gives the possibility to arrange the investigated systems according to the degree of fulfilment the interoperab...

The electromagnetical compatibility (EMC) criteria for radio systems engineering are discussed with multiple channel reuse for frequency, time and code division multiple access (FDMA, TDMA and CDMA) schemes in a mobile environment. The BER is usually used as a measure of digital signals transmission quality. In nonlinear radio-channels with multipa...

The electromagnetic environment is defined by signals emitted by mobile and static radio stations of the communication networks and radar and navigation systems located in a given area. The formulae for coverage as well as for admissible distance analysis in such an environment are presented. The software package for computer calculations of these...

The paper presents application of optimisation methods in planning and resource management for military wireless networks. Basic stages of planning and resources management in military wireless systems are presented. The optimal radio resource allocation problem is formulated as well as the optimal resources management for traffic service with the...