一种基于PCM数字信号的传真控制协议软件检测方案

Fax Control Protocol Checking Software Method based on PCM Data

为了在模拟电话线路上检测G3传真通信,参照软件无线电技术思路,可利用软、硬件相结合的方案。硬件负责从接口上采集PCM数据,软件负责处理PCM话音数据如对PCM数据进行上采样、V.21FSK解码、HDLC帧解析,提取出传真控制协议报文,根据传真控制协议判断当前电话线路上是否正在进行传真通信。而且根据软件所在处理器的处理能力,可实现一路或多路PCM数据处理和信号处理灵敏度可调。该方案可以利用嵌入式处理器的处理性能,实现多路基于PCM话音数据的传真监测,降低硬件实施成本,在硬件平台实现国产化方向具有重要的意义。

For monitoring G3 fax communication on telephony line, and according to software wireless tech- nology, a method in combination of software with hardware is adopted, in which the hardware is responsible to capture PCM audio data, while the software to process PCM audio data, including to implement resam- piing, FSK decoding, HDLC frame detection and extract fax control protocol message, and based on these, to determine whether a fax communication is carried out on the telephone line. This method can be applied to embedded processors with which one or more audio streams can be handled, thus hardware cost can be grandly decreased, and China would have the product of its own independent intellectual orooertv rights.