These new type Digital PLC use SSB, QAM or TCM modulation technology and occupy the bandwidth between several kHz to dozens of kHz with the transmission speed less than 100kbps.

• 新型数字载波机使用的调制技术有SSB，QAM和TCM等，占用带宽为几kHz到几十kHz，数据传输率最高不超过100kbps。