Vivacom's LTE network was found the fastest following measurements conducted by Global Wireless Solutions (GWS) between 15 October and 15 November 2016 on the five existing LTE networks in the country. Speed measurements were done in Sofia, Rousse, Sozopol, Kavarna and settlements on the Bulgarian Black Sea coast.
The measurements concerned three categories, data exchange, speed, and access to social media. At present, Vivacom's LTE network is available to over 6 million people, or over 83 percent of Bulgaria's population in more than 650 settlements.
Source: https://www.telecompaper.com/news/vivacoms-4glte-network-found-fastest--1178786