Delivering video channels over cable selectively, similar to video on demand (VOD), Web page retrieval and other two-way, request-response systems. Switched video, also called "switched digital video" (SDV) and "switched digital broadcast" (SDB), provides greater channel capacity than the traditional method of transmitting all cable channels to the TV at the same time. It takes advantage of the fact that only a small percentage of channels are watched in a particular neighborhood at a given moment.
A New Infrastructure
Switched video requires set-top boxes with two-way communications and a switching infrastructure. When the viewer selects a different cable channel, the set-top box orders that channel from the distribution hub like a video on demand (VOD) program. The distribution hub transmits the channel to the local node, making it available for that neighborhood.
Switched and Non-Switched
When only selected programs are transmitted, the network can provide much greater TV channel capacity over its physical channels.