 espaethDigital PlumberPremium,MVM
join:2001-04-21
Minneapolis, MN
kudos:2
 ·Clear Wireless
| {quantity of stuff} in a {size} bag Once next-generation speeds see broader deployment at lower prices (Comcast is promising full DOCSIS 3.0 deployment by the end of 2010), and vendors begin producing simpler solutions to help Luddites pull Internet video from the web (or PC) to the living room -- Cable operators will have a fight on their hands. Cable executives know it -- which is why they're working hard to hoist the metered billing model upon unwilling consumers. This is completely ignoring the fact that this can only go so far. Comcast's DOCSIS 3.0 deployment is 4 channels downstream -- that's 24MHz (4 x 6MHz channels) out of a 750MHz typical cable distribution plant. Not only do you have less space to work with, but you don't have the efficiency of straight MPEG2 Transport Stream mapping into QAM. You have Video container transport stream (mpeg/real/flash/whatever) as payload inside a layer4 transport header (UDP/TCP), inside an IP header, inside an Ethernet header, mapped into a QAM DOCSIS data channel.
So, you have more overhead on the video signal and less frequency space to work with.
IP Video is cool -- it enables a vast many options that are not available using traditional broadcast methods. It will continue to thrive as an augmentation to existing broadcast video channels. As for replacing broadcast distribution, basic grade school algebra will help you work out why Internet based video won't take over. Unicast streams (to enable the anytime/anyplace nirvana of Internet video) require linear scaling in bandwidth as each subsequent viewer watches the content. Multicast streams have better scaling factors, but require everybody to watch a common feed and incur vastly more overhead than existing traditional video streaming over broadcast channels.
I'm afraid anyone who earnestly believes IPTV is really going to knock out broadcast video is simply standing on the tracks waiting for the freight train of reality to arrive. |
