Broadcom Corporation has introduced a system-on-chip (SoC) solution that dramatically increases the speed of channel changes for cable, satellite or terrestrial digital TV, resulting in latency times as low as 100ms. With channel change times up to five times faster than found on some digital TV services, the FastRTV Channel Change Acceleration technology has the potential to significantly improve the viewing experience, given that up/down channel ‘zapping’ remains one of the most common functions of TV, and is likely to remain so even in the age of on-demand, connected interactivity and content recommendation.
US cable operator Comcast is the first service provider to deploy the technology and is using it for its universal digital transport adapters (uDTAs), which are being used to transition customers from analogue to standard-definition digital services. According to Broadcom, FastRTV dramatically reduces the GOP (Group of Pictures) delay and other key delays in channel change times. “The details are proprietary but GOP delays is one major component of the channel change times,” the company reveals. FastRTV Channel Change Acceleration will not work for IPTV.
A GOP is the number of frames between I-frames in MPEG compression, with decoders looking for the next I-frame (or full compressed frame that does not reference another frame) in order to switch channels. PSI (Programme Specific Information) and Conditional Access are among the other known processes that, in general, could impact the speed of digital channel changes. FastRTV is now available in a wide range of Broadcom cable SD and HD set-top box SoC solutions and also for uDTAs. It works with existing CA systems and does not require changes to broadcast streams, the company adds. The first Broadcom SoC solution to support FastRTV technology for digital cable TV deployments is the Broadcom BCM7002 cable uDTA SoC. The company is talking about “near instantaneous channel changing” with devices using this SoC.