Between September and October 2020, the Regulatory Agency for Electronic Communications and Postal Services (RATEL) undertook comparative measurements and QoS analysis of mobile communications networks (Mobile Network Benchmarking) with all three mobile network operators in Serbia, from the user’s perspective, by measuring the quality parameters of voice service and data transmission service.

Telekom Srbija has shown the best results this year, thanks to significant quality of service improvements across all categories, followed by Telenor, which presented better performances compared to the previous year due to implementing VoLTE service (4G voice transmission, voice over LTE) before the launching of the campaign. Vip mobile, on the other hand, displayed a decrease in the quality parameters on account of the difficulties with DNS (Domain Name System) server functioning.

The mobile communications network testing was performed in 50 cities and along 10000 km of roads across Serbia. The measurements included three categories: large cities, small cities and roads.

During drive test measurements, more than 7000 voice service tests and 7000 sessions for each of the data transmission services in each operator’s network were carried out.

In addition to drive tests, walk test measurements along the following pedestrian zones in Belgrade were performed: Ada Ciganlija, Knez Mihajlova Street, Belgrade Waterfront, Zemunski kej.

For the calculation of the final score, the points relating to the services of voice and data transmission scored by the operators were added up, with the voice service weighting factor being 40% and the data transmission weighting factor 60% (transfer of data 40%, Web browsing 10% and YouTube 10%).

The results achieved by the operators for the services of voice and data transmission by category (large cities, small cities and roads) contributed to the values relative to these services. The calculation for the three categories is made separately, using predefined weighting factors for different categories, namely: large cities - 40%, small cities - 30% and roads - 30%.

As regards voice service, the following types of tests were conducted: call setup successful rate, telephony setup time and quality of voice call.

With respect to data transmission service, the following test types were performed:

• Small file transfer – Download – Designed for measurement of network setup time and user simulation of receiving small files online, such as pictures, mp3 files or e-mails.
• Small file transfer – Upload – Designed for measurement of network setup time and user simulation of sending small files online, such as pictures, mp3 files or e-mails.
• Large file transfer – Download – Designed for testing of network capacities expected to provide maximum continuous data transfer speed.
• Large file transfer – Upload – Designed for testing of network capacities expected to provide maximum continuous data transfer speed.
• Web browsing – Reference page, loading and opening speed testing of reference web pages on mobile phones.
• Web browsing – Live page, loading and opening speed testing of live web pages on mobile phones.
• YouTube – Live video stream quality testing.

The final score was reached by adding up the weighted values of the above categories or services.

The quality of services provided to users by the mobile network operators in Serbia is comparable to the EU quality of service.

The measurement system consists of two measurement vehicles equipped with identical measurement devices enabling the simultaneous testing of all technologies and services.

For voice service testing, Samsung Galaxy S10 smartphones were continuously calling each other within the same network, while the data transmission testing was carried out by means of Samsung Galaxy S9 smartphones.

The benchmarking campaign was conducted by company Crony a.d. Belgrade, in cooperation with Polish company Systemics-PAB, pursuant to a public procurement procedure published and carried out by RATEL.

The Benchmark scores with all detailed information can be found at http://benchmark.ratel.rs/en.