A clock system, or clock network, refers to a fully synchronized network of clocks in constant communication with each other and in which each clock displays precisely the same time as all the others within the system. Although clock networks are commonly employed as synchronized timekeepers in schools, airports and hospitals, a global system of precise worldwide timekeeping that would be based on quantum technologies and orbiting satellites has been under consideration. A global quantum-based clock system would ensure the accuracy of high-frequency financial trades and Global Positioning Systems, while also providing a resource for studies of quantum gravity and relativity.
The need for the development of a reliable and accurately synchronized clock system was clearly indicated by the advent of the radio and television broadcast industries. Both fields operate on precise schedules in which each minute of airtime is planned in advance and all facets of the operation must be synchronized precisely. Emergency 911 dispatch centers across the United States have also relied heavily upon a synchronized clock system.