Telecommunications science

In-flight sensor system for collecting flight information and providing flight safety of unmanned aerial system

In the last decade there has been a rapid development of unmanned aerial aviation and various solutions are sought for gathering information from difficult access points or in cases where there is a risk to operators and technology. ...  read more

A remote controlled system implementation for object video monitoring

In the current article a solution of the problem with information taking from difficult to reach and dangerous earth places is described. The robots will be very useful in this case. In the article hardware part researching and designing ...  read more

A functional model extension of OMA device management

Machine-to-Machine (M2M) communications allow interworking of smart objects such as sensors, actuators and monitors, and development of innovative applications. Remote entity management provides means of managing M2M device life cycles. ...  read more

40 years an anechoic chamber for automatic antenna measurements in Department of Communication Engineering and Technologies at Technical University of Varna

The creation and development of the anechoic chamber for automatic antenna measurements in the Department of Communication Engineering and Technologies at Technical University of Varna since mid 1970’s to now days is described in ...  read more

Three element broadband acoustic array with constant array factor

In the paper a problem of spatial signals filtration with high selectivity is discussed. To approximate the ideal array factor – Kronecker-δ, approximation method of compressed cosines is used. The approximation with third-degree ...  read more

Sensitivity investigations of second-order bandpass/bandstop filter sections

Three recursive tunable biquadratic sections are studied and compared in this paper. The transfer function sensitivities and the impact of the quantization process of the multiplier coefficients on the behavior of the structures were ...  read more

Resource structure for smart metering systems supporting prepaid functionality

Smart metering is one of the main application areas of Machine-to-Machine communications (M2M). Smart meters using M2M can automatically collect and send data about energy supply and usage for monitoring and billing by utilities companies. ...  read more

Design and investigations of approximately linear phase Hilbert transformers

In this work a new design procedure of approximately linear phase (ALP) digital Hilbert transformers (HT) is proposed. First, the possible positions of the transfer function (TF) poles of such HTs realizations are studied and then different ...  read more

Approaching risk management in IT by implementing it in ITIL

The aim of this article is to suggest a way for adopting a strengthened risk management in the ITIL (Information Technology Infrastructure Library) framework which will be based on specific guidelines without changing the framework. ...  read more

Research of miniaturized hexagonal resonators

Abstract: This paper presents and researches the application of miniaturized hexagonal resonators in microstrip bandpass filters in the mobile communication systems. There are investigated both basic topologies of miniaturized hexagonal ...  read more