In both wired and wireless networks, synchronization is an important service for a wide range of applications in distributed systems. This includes radio interferometry. However, literature researches show that many distributed protocols cannot satisfy sub-ns time synchronization accuracy due to asymmetric delay errors, accumulated jitters and because of the strategy used to adjust offsets. This paper proposes a global time synchronization algorithm in distributed networks. The algorithm allows us to minimize asymmetric delays with sub-ns accuracy better than 10ps and achieved global time synchronization. The theory of the algorithm used is presented and analyzed.