缆线调制解调器（Cable Modem或称C.M.），是利用有线电视双向同轴电缆提供互联网相关应用服务的技术，上行频率介于5至50MHz，下行频率占用一个或以上的电视频道带宽（6MHz）。

A cable modem is a type of network bridge and modem that provides bi-directional data communication via radio frequency channels on a hybrid fibre-coaxial (HFC) and RFoG infrastructure. Cable modems are primarily used to deliver broadband Internet access in the form of cable Internet, taking advantage of the high bandwidth of a HFC and RFoG network. They are commonly deployed in Australia, Europe, Asia and the Americas.