| 摘要 |
A star network type topology is implemented for a network synchronization system wherein synchronization information radiates from a centralized primary reference source (46) comprising the global positioning system (GPS). A GPS receiver (54) installed at each mobile switching center (14) and base station (18) of a wireless communications network supplies a stratum 1 classified clock pulse to a local clock (40). The local clock trains to this clock pulse and generates a corresponding stratum 1 classified synchronization clock pulse for controlling timing operations of the mobile switching center or base station. In the event the GPS primary reference source fails (72) or its accuracy degrades (74), a change is made to a tree or linear network type topology wherein the synchronization information flows downstream from the mobile switching center local clocks to the base stations. Operation of the network synchronization system is coordinated through a synchronization manager (52) maintained by the transport network management system (28) of the network. Highly accurate synchronization using these topologies supports the provision of value added services such as mobile station locating (102) and information time stamping. |
