Large transmission capacities are required for high-definition TV (HDTV) and video on demand (VOD) as well as for TV cable networks. However, the DVB-C standard, which has been in use since 1994, sets limits here. The objective of DVB-C2 is to increase transmission capacity by more than 30 % while maintaining the same channel bandwidth.
In addition to the single-carrier modes, orthogonal frequency division multiplex (OFDM) multicarrier modes are now defined in the standard. QAM orders of up to 4096 are now possible, as opposed to a maximum of 256QAM in the case of DVB-C.
In the OFDM modes, like in DVB-T/DVB-T2, pilots are used in order to adapt the receiver to the physical characteristics of the transmission medium by performing "channel estimation".
An improved error correction method, which is already being used in DVB-S2, delivers higher robustness against interference at similar signal-to-noise ratios. Therefore, reliable transmission is also achieved when using high-compression codecs.