Abstract: As one of the largest infrastructures of human beings, fiber optic networks support the information transmission and communication requirements of our society. In addition, further exploration of their usage in precision measurement, sensing and other fields for the integration of communication, sensing, computing, measurement and control, will be a new opportunity for fiber optic networks. This article briefly reviews the basic principle and research on fiber-based time-frequency synchronization, as well as applications in international scientific megaprojects such as the square kilometer array and other radio arrays. Current research on vibration sensing using optical networks, especially in improving vibration positioning accuracy and traffic information sensing, will also be described.