Journal of Physics: Conference Series

Figure 3. Scheme of the TRC network with the display of the system elements that form separate 
communication channels between the train dispatcher and the driver 
The availability factors of different stationary radio stations along the section can be the same (in 
the case of using the same type of radio stations), or differ (if radio stations with different values of the 
availability factors are installed at different points and / or different redundancy of stationary radio 
stations is used at different points of the section). 
The availability factor for radio coverage depends on the level of signal from the fixed radio station 
observed at a particular point of reception. At the same time, communication at a given point is 
possible either with one stationary radio station (Figure 4), or with several (Figure 5) due to channel 
reservation for radio coverage. For each such case, the value of the channel availability factor will be 
determined separately in accordance with the communication channel scheme. 

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Intelligent Information Technology and Mathematical Modeling 2021 (IITMM 2021)
Journal of Physics: Conference Series
2131 (2021) 042096
IOP Publishing
doi:10.1088/1742-6596/2131/4/042096
5
Figure 4. Scheme of the TRC network with the display of the communication channel between the train 
dispatcher and the train driver through one stationary radio station 
Figure 5. Scheme of the TRC network with the display of the communication channel between the train 
dispatcher and the train driver through two stationary radio stations 
As mentioned above, the values of the readiness factors of all elements of the train radio 
communication system, except for the radio channel, can be found on the basis of regulatory 
documents. 
The most interesting task is to determine the value of the radio coverage availability factor. 
Let's consider this task in more detail. To do this, we will use the methodology for calculating the 
characteristics of radio communication channels on the territory of a railway station for the 160 MHz 
range, described in the Methodological guidelines for the organization and calculation of train radio 
communication networks of JSC Russian Railways, approved by order of JSC Russian Railways on 
December 23, 2013 No. 2854r. 
This technique is based on the use of the so-called "basic propagation curves" - graphical 
dependencies of the signal field strength on the distance between the transmitting and receiving radio 
stations (Figure 6). These dependences were obtained as a result of a large number of experimental 
measurements of signals in real conditions at railway stations and statistical processing of the obtained 
data. 
The basic propagation curves are constructed for specific initial data: 

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Intelligent Information Technology and Mathematical Modeling 2021 (IITMM 2021)
Journal of Physics: Conference Series
2131 (2021) 042096
IOP Publishing
doi:10.1088/1742-6596/2131/4/042096
6
– the voltage at the output of the transmitter u
1
= 148 dB, 
– the installation heights of the transmitting and receiving antennas h
1
and h
2
, 
– the gain coefficients of the transmitting and receiving antennas G
1
= 0 dB and G
2
= 0 dB, 
– attenuation in the antenna-feeder paths of the transmitter and receiver B
f
= 0 dB, 
– the probability of reliable communication in place and time is 50%.