Method for assesing the availability of radio channels in the mode with FRCH during a communication session

The paper presents the results of the development of a method for active control of operating frequencies for the transmission mode with pseudorandom frequency adjustment (RFR), implemented directly during a communication session. The traditional methods used in the VHF, VHF, and decameter wave (HF) ranges are considered, and their comparative analysis is performed in terms of applicability, advantages, and limitations. It is shown that most of the existing solutions assume the presence of a highly reliable reverse radio channel for the exchange of service information, which limits their use in conditions of unstable feedback. The calculation results used to estimate the channel resource of decameter radio communication lines are presented. A method of active frequency control that does not require a stable return channel is proposed and described in detail. An analytical apparatus has been developed to evaluate the time characteristics that determine the efficiency of bit information transmission under RFI conditions. Diagrams and graphs illustrating the key provisions of the method are presented. A quantitative assessment of the effectiveness of the proposed concept in comparison with traditional solutions has been carried out, with the introduction of a special indicator reflecting the time gain in restoring channel operability in case of loss of the suitability of pre-selected frequencies. The simulation results are presented, demonstrating the operation of the method in various interference conditions. The main conclusions are formulated and the directions of further research are determined.