PCM modem is the highest speed modem on the PSTN network,which offers 56 kbit/s data signaling speeds in the direction of ISP(Internet Service Provider)to client,which also is the hot subject of ITU TSS SG16.Now its related content is introduced.

• PCMModem是迄今为止在PSTN网上出现的最高速的Modem，它在ISP（InternetServiceProvider）到用户方向上实现了56kbit/s的数据传输速率，本文介绍了有关的技术概况。