issue 1-2

20140102-05
A ZigBee based sensor network for road traffic monitoring
Emil E. Vladkov

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ZigBee is a popular wireless networking protocol for building self-configuring sensor networks. It proves to be both reliable and cost-effective, which makes it a preferred choice for the design of a traffic counting and monitoring ...  read more

20140102-04
Speech quality dependence investigation from transmission channel characteristics and voice encoding methods
Snejana G. Pleshkova, Kalina Hr. Peeva

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This article examines the dependence of speech quality from transmission channel characteristics and speech encoding methods. As speech quality estimation is proposed to use the objective methods for quality control and evaluation ...  read more

20140102-03
Model of information security system based on distributed data transmission
Elitsa D. Gospodinova, Tashko A. Nikolov

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This paper presents a model of security system for protection of information, transmitted over wireless networks. The model is design for implementation in terminals, having more than one independent one from another radio ...  read more

20140102-02
Dynamic queue management of partial shared buffer with mixed priority for QoS guarantee in LTE uplink
Georgi Balabanov, Seferin Mirtchev

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The main objective of this article is to propose and evaluate solutions for QoS guarantee of voice and multimedia traffic at the radio uplink interface of LTE networks. A novel queue named a Dynamic queue management of Partial ...  read more

20140102-01
Improvement of the information services by using means of the IT infrastructure library
Mario Ivanov

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In the present paper, the focus is on the process of determining effective key indicators in ITIL (Information Technology Infrastructure Library), and is provided an overview of the most popular key performance indicators. ...  read more

20150102-full
Issue 1-2, 2015

ELECTROTECHNICA & ELECTRONICA E+E

Vol. 50. No 1-2/2015
Monthly scientific and technical journal
Published by:
The Union of Electronics, Electrical Engineering and Telecommunications /CEEC/, BULGARIA

20150102-full

C O N T E N T S

TELECOMMUNICATIONS SCIENCE

Seferin T. Mirtchev
Internet evolution, teletraffic and QoS: a survey of network traffic 2

Emil E. Vladkov
A general concept and implementation of a DSP-based QAM digital modulator 18

Peter Z. Petkov, Boncho G. Bonev
Narrow beamwidth antenna for DTH satellite television 26

Veselin B. Demirev
Recent trends and future developments of SCP-RPSC high altitude platform systems 30

CONTROL ENGINEERING

Lyuben A. Iliev, Daniel L. Todorov, Nikolay P. Mihailov, Petko K. Mashkov


 ...  read more

20150102-07
Study of the elements of the photovoltaic system
Dimitar D. Arnaudov, Nikolay L. Hinov, Ivan I. Nedyalkov

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In this paperwork has been made a study of the elements of an off-grid photovoltaic system for power supplying of telecommunication systems and telecommunication modules. The laboratory model is described. The bi-directional ...  read more

20150102-06
Model order reduction for a single machine infinite bus power system
Kamen L. Perev

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The paper considers the problem of model order reduction for a single machine infinite bus power system by using a Legendre polynomials approximation based balanced residualization method. The model examines the small signal ...  read more

20150102-05
Specialized controller for managment of industrial and consumer lighting
Lyuben A. Iliev, Daniel L. Todorov, Nikolay P. Mihailov, Petko K. Mashkov

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A lighting controller prototype is presented, which is intended to be used for lighting control in poultry farms, where a precise control of the lighting cycle and intensity is required. Such farms require 24 hours per day ...  read more

20150102-04
Recent trends and future developments of SCP-RPSC high altitude platform systems
Veselin B. Demirev

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A new technology for broadband wireless access to the fixed networks, named High Altitude Platform Systems (HAPS) is under development now as an effective solution of the “Last mile” communication problems. The application ...  read more