With digital accounting for 43 percent of basic cable subs at end-2005 and growing, cable systems can look to the day in the future when they can reclaim their analog spectrum to instead transmit more capacity-efficient digital services.
Cable operators are offering digital services such as HDTV, video-on-demand and Internet protocol (IP) voice with various equipment configurations, but available bandwidth remains a constant concern. "The continual introduction of additional advanced services unquestionably puts a strain on network capacity," says Ian Olgeirson, senior analyst with Kagan Research. "However, the cable industry has a host of options at its disposal to increase the available bandwidth and more efficiently use existing capacity."
In looking at capacity allocation, an analog TV channel typically occupies a 6 MHz slot (MHz is a megahertz, a unit of frequency equal to one million cycles per second, an indicator of data flow speed). Thus, a cable system allocates about 360 MHz for 60 analog channels. As a typical cable system has 750 MHz of total capacity with hybrid fiber coax (HFC) lines, the 60 analog TV channel package gobbles up nearly half of its capacity.
The timeframe for when cable will shut down analog remains uncertain. One possible scenario is not a total shutdown, but a gradual reduction in analog channels, which instantly opens capacity for digital services.
Cable operators are offering digital services such as HDTV, video-on-demand and Internet protocol (IP) voice with various equipment configurations, but available bandwidth remains a constant concern. "The continual introduction of additional advanced services unquestionably puts a strain on network capacity," says Ian Olgeirson, senior analyst with Kagan Research. "However, the cable industry has a host of options at its disposal to increase the available bandwidth and more efficiently use existing capacity."
In looking at capacity allocation, an analog TV channel typically occupies a 6 MHz slot (MHz is a megahertz, a unit of frequency equal to one million cycles per second, an indicator of data flow speed). Thus, a cable system allocates about 360 MHz for 60 analog channels. As a typical cable system has 750 MHz of total capacity with hybrid fiber coax (HFC) lines, the 60 analog TV channel package gobbles up nearly half of its capacity.
The timeframe for when cable will shut down analog remains uncertain. One possible scenario is not a total shutdown, but a gradual reduction in analog channels, which instantly opens capacity for digital services.