Abstract: Traditional network timing and satellite timing methods are restricted by timing accuracy and deployment environment. It is challenging to meet the demands of mobile network services for high-precision synchronization. To solve this problem, a design based on the low-cost baseband timing module for mobile terminals is proposed. A prototype consisting of software-defined radio-based 5G base station and Zhanrui module is implemented. An end-to-end error source model, principle and implementation of the network timing technology based on the air interface physical layer signal are defined. Issues including the air interface delay compensation method, error perception method and the robust statistical compensation method are discussed so as to achieve sub-microsecond synchronization accuracy in the mobile network. The experimental results show that the single-time timing accuracy is better than  10 - 7 s.

Key words: mobile network timing, absolute time synchronization, mobile communication, high precision timing