Research Of Time Synchronization Technology In TD-SCDMA System

TD-SCDMA is one kind of technology of 3G which is proposed to ITU by China in 1998. Now, it is asready one standard in 3G mobile technology and China Mobile is using this technology.TD-SCDMA system has a hash requirement for the time synchronization of the whole network. Currently solution is to install GPS receiver system in the core equipment room and every base station to realize synchronization between base station and base station controller and among every base station. However, on one hand, the installment of so many GPS receivers will lead to higher deployment and maintainence cost on the whole network. On the other hand, GPS system belongs to American Army. It has a big threat on the security of oue national telecommunication infrastructure. As there is a lot of research has been achived about using IEEE 1588v2 protocol in packet transport network to realize the transmission of high accuracy time synchronization signal, it can be considered that with packet transport network in TD-SCDMA system to realize time synchronization signal to be transmitted and distributed within the physical line. Then, it can avoid the requirement of istalling GPS receiver in every base station. At the same time, the Compass Navigation Satellite System has gradually been used in commercial. It can be considered that with CNSS receiver systemas a redundancy for GPS receiver system in time source (core equipment room) to improve the security of our national telecommunication infrastructure.Because of hash time synchronization requirement coming from TD-SCDMA base station, the paper dicussed time synchronization solution based on TD-SCDMA system, posed out the view that using IEEE 1588v2 message to realize time synchronization; then, it can adopt packet time transport network in TD-SCDMA system to realize time synchronization signal to be transmitted and distributed within the physical line; the thesis searched how to realize IEEE 1588v2 protocol with BCM56130, meanwhile, it shows the procedure that how equipment realizes time synchronization with IEEE 1588v2 protocol; for the choice of time source of TD-SCDMA system, gave out using CNSS receiver system to take place of GPS system; dicussed the network solution for time transport network of TD-SCDMA system and showed out the protection solution; at the end, with the experience of test about time synchronization network of TD-SCDMA system in China Mobile, proved the usability of adopting IEEE 1588v2 protocol in time transport network,the flexability of network solution and the feasibility of adopting CNSS system as a time source for TD-SCDMA system.