US cable operator Cablevision has confirmed that it will offer 15 high definition channels from sibling company Voom using switched digital video.

The technology allocates capacity on an on-demand basis, using bandwidth to deliver services only when they have been requested by a customer's set top box. This enables cable operators to make a greater number of bandwidth-intensive services available, as swathes of spectrum do not need to be reserved in block.

Cablevision plans to roll out a new fleet of high definition set top boxes that support the technology and will offer them free to subscribers who possess devices that are incompatible. Some equipment with built-in digital cable tuners, such as some models of TiVo digital video recorders, will require a switched digital "tuning resolver" to ensure continued reception of channels delivered using the system.

Switched video for the delivery of linear TV channels has yet to be deployed by a UK cable operator. Last November, Virgin Media's content chief Malcolm Wall admitted that the service is "bandwidth constrained" and will only "add HD channels on a selective basis".