Patent ID: 6842508

Claim:
A voice mail service system for a private switching system comprising: a system matching circuit and a system matching section configured to couple to a private switching system, which is a system of higher rank, so as to interface all information in relation to a call and management of a call including call-related messages, exchanging voice messages, recording and reproduction of processed voice data and perform interfacing for communication between a control section and the private switching system, which is a system of higher rank; a voice data memory to provide a voice mail function, and to store voice guide information in an address sector of a corresponding channel; a voice and signal processor to store voice data of the extension subscriber in the voice data memory and retrieve it so that the voice data can be transmitted; a communication controller to manage a state of each channel matching with the private switching system, which is a system of higher rank, process channel errors, and maintain and repair the channel and wherein the communication controller directly and automatically determines a busy or nonresponsive state of the subscriber in response to an incoming communication from a terminal and transfers the call to the system matching circuit and system matching section; and a control circuit to match with the private switching system, which is a system of higher rank, to control an operation for maintaining the voice mail function, wherein the voice and signal processor comprises: a vocoder coupled to the private switching system and configured to compress and modulate voice signals; a first high speed RAM to store an algorithm for a compression-modulation and a demodulation of the voice signals by the vocoder; a first buffer to store the voice signal compressed and modulated by the vocoder and the voice signal outputted; a first dual port RAM to maintain a smooth transmission and a smooth reception of the compressed and modulated voice signal to be stored in the voice data memory and the voice signal outputted; and a first interface circuit coupled to the vocoder and the first dual port RAM, so as to arbitrate and control occupations of a system interface bus by the vocoder and the first dual port RAM.