Digital Video Broadcasting – Cable (DVB-C) is the name of the technology that enables cable networks to distribute a large number of TV channels. The cable operator uses different frequencies to carry various channels over the same coaxial cable. DVB-C transmits digital audio/digital video streams using MPEG-2 or MPEG-4 compressions standards and file formats.
The DVB-C technical specification, which uses the same technology principles as terrestrial broadcasting, has been extremely efficient for content distribution.
TV channels may be transmitted through an open signal or using an encryption system, named Conditional Access (CA), which is usually embedded in the set-top-box provided by the cable operator.
Cable networks are likely to evolve to all-IP, which means that only internet protocol based technologies will be used instead of other technologies. Cable operators will abandon the use of DVB-C and will only use IP based DOCSIS to carry television services. The transition to all-IP has already started but will take some time to be completed. All-IP will change every aspect of television delivery and gives operators more flexibility.