M. Bednarek

Reliability analysis of radioamateur communication

Abstract The following article describes diagnostic and reliability aspects of amateur radio communications. The intention of precise measuring of quality and accuracy of every contact was present in ham radio from very beginning. The reports were sent and they are still used today, in many variants. In time, the tools to measure ionosphere state and propagation conditions emerged. They are fundamental for communication, especially long distance ones. The article concentrates on description of digital amateur mode, JT9. This mode is very effective, enables worldwide reach and requires simple tools.

Selected Aspects of the Security of the Process Data Transmission in the Distributed Control System

Abstract Communication between the process stations of the distributed control system is carried out. By the supervision and therapeutic systems of the stations communication process diagnosis is performed. Supervision and therapeutic systems are responsible for the security of transmitted data. The security is considered in this article mainly in the aspect of resistance to external destructive factors on the data transmission process. It is assumed that the transmission security can be provided by mechanisms protecting the integrity of the transmitted data. Correctness of the data is controlled by using one-way hash function calculated on the basis of the transmitted value variable and also is attached to the transmitted data. This allows to maintain the integrity of the transmitted process data. A solutions using one-way hash function to protection of the transmission before changing message contents (caused by eg. intruder interference) are proposed in the article.

CONCEPT OF THE DATA TRANSMISSION SECURITY IN THE MOBILE DIAGNOSTIC SYSTEM / KONCEPCJA ZABEZPIECZENIA TRANSMISJI DANYCH W MOBILNYM SYSTEMIE DIAGNOSTYCZNYM

Abstract The concept of security data transmission in a mobile diagnostic system composed of the process stations (remote parts of the supervising and therapeutic system) and the operator station (local part of the supervising and therapeutic system) is presented. Process stations are connected to the operator station via radio modems. It allows the installation in mobile facilities. Communication between stations is realized via wireless access points. The examples of the application of the presented issues in mobile systems, as well as the potentially locations of the security risks of transmission are given. The possible options for secure communications are described. The assumptions of the concept of a secure communication in the diagnostic system are explained. Streszczenie W artykule przedstawiono koncepcję zabezpieczenia transmisji danych w mobilnym systemie diagnostycznym złożonym ze stacji procesowych (odległa część systemu dozorująco-terapeutycznego) i operatorskiej (lokalna część systemu dozorująco-terapeutycznego). Stacje procesowe systemu są połączone drogą radiową za pomocą radiomodemów ze stacją operatorską, co umożliwia instalację stacji w ruchomych obiektach. Komunikacja pomiędzy stacjami procesowymi odbywa się za pomocą bezprzewodowych punktów dostępowych. Podano przykłady zastosowania prezentowanych zagadnień w systemach mobilnych, a także potencjalne miejsca występowania zagrożeń dla bezpieczeństwa transmisji. Opisano możliwe warianty zabezpieczenia komunikacji. Przybliżono założenia koncepcji bezpiecznej komunikacji w systemie diagnostycznym.