Switched Digital Broadcast (SDB) is a new technology that has generated considerable interest because it promises better utilization of HFC bandwidth combined with the potential to offer the customer a virtually unlimited number of broadcast (linear) channels. However, progress on implementation has been slow, and the focus has been on vertical solutions that do not inter-work with other services such as digital ad insertion, VOD, and network-based PVR. Moreover, there is no clear revenue model for SDB; it is a technology rather than a service.
SDB promises the greatest increase in bandwidth efficiency when it is applied to the 'long-tail' content which is rarely viewed. However, it is difficult to predict which channels will represent this group and how real-world events dynamically change the popularity of a given channel. What is needed is an intelligent system that can adapt to instantaneous changes in channel viewing behavior.
This paper describes an approach to providing Switched Digital Services that combines the video digital processing required for ad insertion (both into broadcast and on-demand programming) with the ability to switch video in unicast or multicast modes. Therefore future digital switched services must seamlessly include support for advanced features such as targeted Ad Insertion, Fast Channel Change, VOD, and Network PVR.