Wednesday, April 11, 2007
"Switched Digital Video" basically relies on the fact that people generally don't watch more than one channel on a given TV set at the same time. That means that the cable TV provider really only has to deliver one channel to that particular TV set at any given time. Using conventional cable TV technology, the method of delivering programming follows more of a "shotgun approach" in which all channels are delivered to all subscribers at the same time and the individual set top cable boxes are left to sort out all of the different channels. With "Switched Digital Video," the cable TV provider only sends the channel that the viewer wants to watch. Since this limits the number of channels being sent at any given time, more channels of data intensive TV programming (like high definition television) can be provided to choose from.
Right now, with the shotgun approach to cable TV, cable TV providers have to make hard choices about what channels they provide. Since most cable TV providers are running at capacity and expanding bandwidth means an expensive and labor intensive process of digging up old cables and burying new ones, they have to be very picky about what channels they provide. This situation is made even tougher by the fact that HDTV programming can require between six and ten times the bandwidth of normal TV (depending on whether it's in 720p or 1080i resolution). This means that if a cable TV provider wants to add an HDTV channel to its lineup, it either has to make expensive upgrades or drop as many as ten normal channels. Considering that at least one satellite TV provider plans to provide as many as 100 national network HDTV channels by the end of 2007, the cable TV industry has a serious problem.
Now with "Switched Digital Video" there's a sign of hope for the continued ability for the cable TV industry to be competitive in the world of HDTV.