In contemporary monitoring and fleet management systems, navigation systems and mobile networks have an important role. The use of navigation systems allow geting current parameters, like position (location), of the desired objects. This work presents an overview of the existing satellite navigation systems. It describes their characteristics with regard to the accuracy of locating, availability and improvements over previous systems. Mobile networks provide information (of the current and past vehicle location) transfer in real time. Combined -vehicle fleet tracking and the use of mobile networks are described. Possibilities of integrating satellite navigation system with vehicle sensors and communication modul are explained. And the requirements for service provider system infrastructure, which are used for vehicle fleet tracking, are defined, i.e. mobile networks architecture.