METHOD AND SYSTEM FOR ESTIMATING FREQUENCY UNCERTAINTY OF MOBILE RADIO SYSTEM WHICH IS ABLE TO USE TWO DIFFERENT MOBILE RADIO NETWORKS

摘要

PROBLEM TO BE SOLVED: To provide a method for estimating the frequency uncertainty of frequencies. SOLUTION: In this method of estimating the relative frequency uncertainty between two parts of a mobile radio system which is able to communicate via two mobile radio networks at specified first and second frequencies, each part of the system has a clock from which the specified frequency is derived and the uncertainty is estimated by measuring the number of pulses of each of clocks during the time window of duration T starting at a time (t). The method includes the following steps: a) measuring the number of pulses of each of the clocks at n intermediate times t+(T/n), t+(2T/n),..., t+(nT/n), when n is a positive integer, b) storing the number of clock pulses thereby obtained in memory, and c) calculating the relative frequency uncertainty at time t+T from the numbers of clock pulses stored in the memory.