APPARATUS AND METHOD FOR SELECTING REFERENCE CLOCK FOR GENERATION OF NETWORK SYNCHRONOUS REFERENCE CLOCK IN MOBILE COMMUNICATION EXCHANGER

摘要

PURPOSE: An apparatus and a method for selecting a reference clock for generation of a network synchronous reference clock in a mobile communication exchanger are provided to supply a reference clock for generation of a network synchronous reference clock to a network synchronous block by automatically performing a switching system to a different E1 framer when an error occurs in an E1 framer. CONSTITUTION: A plurality of trunk line interfacing units(100) receive a voice and character data from a different switching center(1), extract a reference clock for generation of a network synchronous reference clock from the voice and character data, and transmit it to a network synchronous block(400). A plurality of E1 framers(101) receives the voice and character data from the switching center(1) through a backboard(300), extracts a reference clock for generation of a network synchronous reference clock from the voice and character data, and mounted between mutually different exchangers to interface them. A controller(102) receives a reference clock select control signal from an upper control block(200), it outputs a reference clock select signal corresponding to the reference clock select control signal to a reference clock selector(103). The reference clock selector(103) receives the reference clock select signal from the controller(102), and selects an E1 framer(101) for supplying a reference clock according to the reference clock select signal. The upper control block(200) selects a plurality of E1 framers(101) to be used for reference clock supply , and outputs it. A backboard(300) connects the switching center(1), the network synchronous block(400) and the plurality of trunk link interfacing units(100). The network synchronous block(400) receives the reference clock for generation of the network synchronous reference clock outputted from the reference clock selector(103), generates a network synchronous reference clock by using the reference clock, and supplies it to each block mounted in the exchanger.