THE MAIN DIRECTIONS OF THE CONCEPT OF COMMUNICATIONS IN A LOW-ORBIT RELAY SATELLITES COMMUNICATION SYSTEM

Рассмотрены проблемы организации связи в системе персональной подвижной спутниковой связи (СППСС) на низкоорбитальных спутниках-ретрансляторах для обеспечения широкополосного доступа к сетям передачи данных с применением небольшого персонального абонентского терминала (АТ). Дан краткий анализ существующих СППСС, определены требования к системе связи,представлены основные направления организации информационного обмена,предложенорешение создания АТ. The paper is devoted to the problems of communication organization in the low-orbit personal mobile satellite communication system for providing broadband access to data transmission networks using a small personal subscriber terminal. A brief analysis of the existing systems of personal mobile satellite communications is given, the requirements for the communication system are defined, the main directions of information exchange organization are considered, and a solution for creating a subscriber terminal is proposed.

Principles of creating a phased active antenna array for mobile satellite terminals based on a multilayer printed circuit board

The paper describes concept of the phased array antenna made on a multilayered printed circuit board for the subscriber terminal of a modern Ka-band mobile communication system. Two options of the array are considered: Rx- and Tx- arrays. The architecture of the PAA is described, and main problems arising when creating such antennas are discussed. The ways of their solution are offered. The multilayer printed radiator is described in details. The proposed concept will be useful for design of the phased array antenna experimental model.

Identification of Subscriber Terminals of Infocommunication Networks based on the Model of Forming Images in Modern Computer Systems

One of the important tasks of such theories as theories of pattern recognition and the theory of information security, is the task of identifying terminals of information and telecommunication networks. The relevance of the topic is due to the need to study methods for identifying computer network terminals and build information security systems based on the knowledge gained. The main parameters that allow uniquely identifying subscriber terminals in the network are address-switching information, as well as a number of parameters characterizing the software and hardware of the computer system. Based on the obtained parameters, digital fingerprints of subscriber terminals are generated. The using anonymous networks by users of subscriber terminals and blocking of the methods of generating and collecting digital fingerprint parameters, does not allow to achieve the required degree of identification reliability in some cases. Based on the peculiarities of digital image formation in modern computer systems, many transformation parameters make impact on the output graphic primitive, thereby forming a digital fingerprint of the subscriber terminal, which depends on the placement of samples in a pixel, the algorithms used to calculate the degree of pixels influence, and also the procedures used of smoothing images in the graphics subsystem. In this paper an original model of image formation by means of a subscriber terminal web browser that allows to increase the degree of reliability of identification under conditions of anonymization of users of information and telecommunication networks is propesed. Features of the digital images formation in the graphic subsystems of modern computer systems are substantiated. These features allow identification under a priori uncertainty regarding the modes and parameters of information transfer.