Hi-fidelity line card

DETAILED DESCRIPTION In accordance with an illustrative embodiment of the present invention, a high-fidelity voice/audio communication system is provided.
According to an aspect of the illustrative embodiment, a high-fidelity SLIC (HSLIC) device is provided that combines traditional BORSCHT functionality with high fidelity sampling and compression techniques.
The HSLIC preferably resides on a single plug-in line card contained within a multi-card chassis.
The line card includes an analog interface that connects to a two-wire subscriber line, a high fidelity codec for sampling the analog signal at a high resolution and converting high rate digital signals to an analog signal, a voice processing client running on a microprocessor and associated digital memory.
The voice-processing client forms data packets and forwards them, via a network interface circuit, to a communication network for transmission to a distant end subscriber.
The high fidelity codec preferably has a sample rate of at least twenty thousand samples per second, and no less than 4096 quantization levels, and up to a sampling rate of 44.
1 kHz with 65,536 quantization levels.
The voice processing client preferably includes an Internet Protocol (IP) processing client, Session Initiation Protocol (SIP) client, a Real Time Protocol (RTP) client, and other components of a communication protocol stack for establishing a connection over a packet based network by way of the network interface circuit, such as UDP and IP.
The high fidelity line card preferably provides line voltage and signals to operate a standard POTS subscriber device, where the standard POTS subscriber device may or may not provide enhanced sound characteristics, such as a broadband frequency microphone and speaker.
The data packets preferably contain compressed data samples, where the compression algorithm, is a negotiated configuration parameter.
Further parameters include the codec type and IP address.
The line card establishes a high fidelity audio connection by obtaining the address of the called party; sending an invite request to the called party; receiving an okay signal indicating that the request was received; sending an acknowledge signal; quantizing audio information at a sampling rate greater than twenty thousand samples per second with a resolution of no less than 4096 quantization levels; and, packetizing the quantized data for transmission to a remote device