During April 2021, the Regulatory Agency for Electronic Communications and Postal Services carried out extensive measurements and analysis of the quality parameters of services available to mobile communications network end-users of operators: Telekom Srbija, Telenor and A1 Srbija d.o.o, along rail corridors X and XI (Rail Corridors Benchmarking).

The Rail Corridors Benchmarking measurement trajectory included the following sections:

1. Batajnica-Šid-Batajnica, branch of corridor X
2. Belgrade-Vršac-Belgrade, branch of corridor XI
3. Novi Sad-Subotica-Novi Sad, branch of corridor Xb
4. Belgrade-Prijepolje-Belgrade, branch of corridor XI
5. Niš-Dimitrovgrad-Niš, branch of corridor Xc
6. Niš-Preševo-Niš, branch of corridor X
7. Niš-Belgrade-Niš, section of corridor X

The measurements did not include railroad section Belgrade-Novi Sad of corridor X, which is currently not in operation due to reconstruction work.

The network data were collected by using measuring equipment and performing voice and data transmission tests as well as simultaneous measurements using scanners for radio parameter collection. All three mobile communication networks were tested at the same time, on identical routes, via the same test telephones. The measurements were carried out inside a moving train, on all sections of corridors X and XI.

Rail Corridors Benchmarking measurements included almost  2100 km of railroads in the Republic of Serbia. During the campaign, more than 2000 calls and  4500 data transmission sessions were performed, in each of the operators’ networks, in all available technologies (2G, 3G, 4G).

A detailed display of the parameter values regarding the quality of voice and data transmission services in mobile communications networks, including radio signal coverage maps, along with the legend for the signal level by the transmission technology in the mobile communication networks of Telekom Srbija, Telenor and A1 Srbija d.o.o, according to rail sections, can be viewed here.

Noteworthy are no coverage zones:

• Belgrade-Prijepolje (particularly: Valjevo-Užice-Prijepolje),
• around Sićevačka klisura along rail branch Niš-Dimitrovgrad of corridor Xc,
• in the area of Grdelička klisura along branch Niš-Preševo of corridor X,
• section Belgrade-Niš of rail corridor X.

Rail Corridors Benchmarking results demonstrate the lack of the operators’ attention regarding the railroad corridors mobile communications network coverage. Quality parameter values of the electronic communications services are uneven, ranging from excellent to very poor.

Other railway directions, with the exception of those in Vojvodina, are not sufficiently covered by the operators’ mobile communication networks, resulting in an unsatisfactory user experience.



Figure 1: Typical 4G coverage map of section Belgrade-Prijepolje



Table 1: HTTP Small file download along section Niš-Dimitrovgrad

Table 3: Voice call setup time along section Niš-Dimitrovgrad

Table 4: Quality of voice service along section Niš-Dimitrovgrad