The paper explains the basic principle of operation of each mobile network, all generations of mobile networks, ie from the period when the idea of ​​mobile networks began to be born. It was explained how the 5G system was developed and what needs to be developed for the 5G infrastructure to work. With the arrival of the 5G network, the use of mobile systems will greatly expand, more precisely, the 5G system, if it continues like this, will be present in every segment of our society in a few years. 5G infrastructure will enhance and accelerate the growth of the world economy, but it will also make the life of "ordinary" people easier and safer. The prevalence of 5G network at the global level is still very small, the development of 5G network depends on the development of the country in which it is implemented, Well-to-do countries are leaders in the development of 5G infrastructure, both in the world and in Europe. In Croatia, 5G infrastructure is still lagging behind the rest of Europe, we do not have any active 5G network yet, but we are on the right track and we hope that this situation will change soon. Various organizations are being formed around the world to stop the development of 5G infrastructure, stating that it causes various health problems, mostly the creation of brain tumors. How much truth there is in such claims and what these organizations demand is explained in the last chapter.