Модернізація мереж поїзного радіозв’язку гектометрового діапазону

Abstract

UA: Впровадження мереж рухомого радіозв’язку на залізницях України розпочалося на початку 50-х років минулого століття на основі радіозасобів гектометрового діапазону радіохвиль. Використовуючи направляючі лінії, радіозасоби КХ діапазону забезпечують необхідну дальність в умовах експлуатації. На цей час їх використання не відповідає сучасному розвитку цифрових радіотехнологій і додаткових сервісів у мережах поїзного радіозв’язку. Збереження в лінійних системах радіозасобів гектометрового діапазону є анахронізмом, і їх використання недоцільне в подальшому, бо стримує запровадження цифрових мереж.

EN: The introduction of mobile technological radio communication facilities on the railways of Ukraine began after the development of the first railway radio station ZHR-1, which operated in the hectometer range of radio waves. According to the Frequency Plan, two channels with a frequency of 2.13 and 2.15 MHz in the hectometer range with a radio wave length of 141 m were allocated for the organization of technological radio communication networks on railway transport. The significant wavelength of hectometer range oscillations requires the use of extended linear antenna systems. The implementation of effective compact antennas in the GM range is difficult, especially for mobile and portable radio equipment in mobile radio communication networks on railway transport. The efficiency of locomotive antennas with a length of 7-12 m installed at a height of 0.8-1.0 m above the roof of the locomotive is 3-4 %. Significant levels of industrial radio interference require an increase in the level of useful signals with low efficiency of locomotive antennas. Thus, in the operating range of 2.13 MHz on sections electrified by alternating current, the minimum level of GM band signals is 72 dBmkV or more than 3000 mkV. The range of train radio communication channels of the hectometer range when using stationary antennas is only 4.2 km on sections of alternating current, which does not meet the requirements of the PTE. When using guide lines, a waveguide wire or colored wires of longitudinal power supply, the range on sections of alternating current increases to 11.4 km. Highfrequency signal excitation systems in the wires of 6.10 kV high-voltage lines create a voltage of 14.2 V. In order to reduce the impact on the characteristics of radio signals, automation power supplies are connected to the wires of the high-voltage line through blocking circuits. When the properties of the blocking circuits are degraded, the penetration of train radio signals causes a deterioration in the quality of communication and can create a dangerous source of electromagnetic interference for microprocessor automation devices, the voltage of which exceeds the standards for resistance to conductive interference (10 V). When using guide lines, operating costs increase. When using VHF radio equipment, the radio communication range can be up to 26 km for sections with autonomous traction, up to 15.6 km on DC sections and up to 11.8 km on AC sections, which meets the requirements for organizing networks within railway sections. This is a convincing argument in favor of implementing linear VHF networks in the VHF range. Thus, the organization of linear VHF networks in the VHF range allows you to ensure compliance with the radio communication range conditions and ensure the implementation of modern digital networks in duplex mode, handover and other services of digital systems.