| 摘要 |
PURPOSE: A method for generating a dial tone of a WLL(Wireless Local Loop) is provided to create 2 tone frequency-type dial tones in an existing WLL terminal structure without using additional hardware, thereby creating various dial tones. CONSTITUTION: A system initializes a register of a microcomputer, and executes initialization processes of tasks as creating the tasks. The system controls a vocoder built in the microcomputer, and transmits data for generating a tone frequency to a CODEC. The CODEC generates tone frequencies such as cos(f1+f2) and cos(f1-f2) by using the data transmitted from the vocoder, and sums up the tone frequencies as one by a trigonometric function formula, then generates tone frequencies such as 2cos(f1)cos(f2).
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