Cable IP and Multimedia Access (CIMA) specifies the protocol and architecture for transmitting IP data and digital multimedia (video and audio) over digital cable (HFC or coaxial cable) access networks and in-home networks. CIMA has been developed and is being assessed by telecommunications experts become an industry standard in providing cost effective solution to manufacture and implement complex digital cable system.

　　Cable networks are tree structured networks with amplifiers and taps. They are traditionally designed for one-way services. As a result, cable networks present impairments in two-way communications, such as micro-reflections, narrowband ingress noise, and burst (or impulse) noise. Existing technologies of data over cables compromise the performances in the presence of severe impairments, such as might happen in cable networks of some countries. CIMA technology is designed to combat the impairment more efficiently. It is designed from ground up and takes advantages of the best and proven technologies of today.

　　In addition, CIMA specification unifies the communication protocols over the last mile cable network and in home network so that the two networks can interoperate smoothly. This reduces the overall cost of in-home and out of home network systems.