Doug Jones
Chief Architect,
Cable
Q. Everyone's talking about switched broadcast these days. What are the benefits of the technology?
A. Extensive field trials have shown that switched broadcast frees up between 50% and 80% of the digital spectrum, depending on design parameters. This is because switched broadcast transmits programs to a service group only when a subscriber within that group requests it, and removes it when it is no longer being viewed. Years of analysis have shown that, at any one time, less than half of the programs in the digital tier are being watched. Consequently, a switched tier requires fewer QAMs than are needed by traditional broadcast tiers. For example, 80 programs that would normally consume 8 QAMs may need just 3 QAMs when switched.
Q: Why are we hearing so much about switched broadcast now?
A: A number of factors, including increasingly savvy subscribers, and the maturity of the technology, are converging to propel switched broadcast to the forefront of almost every cable operator's business model.
There's an analogy here with DOCSIS, an area where I've been personally involved for many years. Just like DOCSIS, switched broadcast opens the door to more possibilities, both for cable companies, and subscribers. Switched broadcast gives cable operators the opportunity to dramatically expand the content they provide to subscribers, enabling them to offer HD versions of SD programs, broaden VOD choices, or add higher speed broadband tiers. They can also leverage the spectrum reclaimed by switched broadcast to provide long-tail programming that may include content addressing a wide array of hobbies or interests, and expanded lineups of international TV shows.
Q. That sounds good. How can switched broadcast be implemented by cable operators?
A. BigBand Switched Broadcast deploys quickly at both headend and hub locations. Our headend solution acquires and processes content, converting it from VBR (variable bit rate) format to CBR (constant bit rate), before distributing it over a standard multicast IP network to the hubs. Edge QAMs within the hubs replicate programs and switch them to nodes where and when the subscribers have actively requested that programming. Our server suite manages communications with STBs (set-top boxes) to determine which programs are being viewed by subscribers.
Q. How does switched broadcast from BigBand Networks interoperate with platforms from other vendors?
A. BigBand Networks is committed to provide, open, standard-based solutions capable of communicating and processing video, voice and data. We are working directly with operators to provide solutions that meet their back-office specifications. In addition, our solution leverages protocols such as IGMP (Internet Group Management Protocol), SNMP (Simple Network Management Protocol) and utilizes proven transport methodologies such as DWDM, SONET and GigE for effective and economical traffic of video. In addition, our solution works with any STB return channel, including Scientific-Atlanta, Motorola and DSG (DOCSIS Set-top Gateway).
Q. How do you see the current generation of switched broadcast evolving?
A. BigBand Switched Broadcast can be a stepping stone to ever greater personalization of digital video services for subscribers. One of the ways to achieve this is migrating to switched unicast. In a switched unicast environment, each viewer receives a unique program stream, providing cable operators the ability to offer new and enhanced services and match advertisements to viewer's interest more closely. Personalized news and music networks are two additional examples of how the evolution of switched broadcast can enable greater content personalization. All of these enhancements can be significant sources of revenues for cable operators in the future.