> -----Original Message----- > From: opendtv-bounce@xxxxxxxxxxxxx=20 > [mailto:opendtv-bounce@xxxxxxxxxxxxx] On Behalf Of John McClenny > Sent: Monday, February 28, 2005 5:01 PM > I was in a meeting last week with some cableish vendors and=20 > they were talking about the MSOs moving to a (not the right=20 > technical name ) switched video delivery nearer the edge. =20 > Basically IP multicast with RF channel multiplexing instead=20 > of a shared Ethernet network. They said that the MSOs were=20 > starting to deploy this and that it is an intermediate step=20 > toward full IP network. I hadn't heard of this functionality before. >=20 > This makes an IPTV and a MSO network look just about the same=20 > from an application perspective. >=20 > Any cable people know anythig about this? Yes. Switched broadcast is the term that gets thrown about. There are variations on the theme, but in essence for the less popular channels you only send the continuous feed to a given edge device if someone attached to that edge device requests it. The 20% or so popular channels are distributed as they are now and the remaining 80% go switched, allowing their channels to be reclaimed and made=20 available for on demand applications.=20 The continuous feed may be multicast, in which case the edge device has to know how to join the multicast group etc. Or it may originate in a central server as a shared, on-demand unicast feed. If multiple people on the edge device 'tune' to the channel, they share the feed. Each approach has its pros and cons. gary Gary Hughes Director of Media Engineering Broadbus Technologies, Inc. ghughes@xxxxxxxxxxxx v: 978 264 7919 f: 978 264 9108 -------------------------------------------------------- This email message and any files transmitted with it contain = confidential information intended only for the person(s) to whom this = email message is addressed. If you have received this email message in = error, please notify the sender immediately by telephone or email and = destroy the original message without making a copy. Thank you. ---------------------------------------------------------------------- You can UNSUBSCRIBE from the OpenDTV list in two ways: - Using the UNSUBSCRIBE command in your user configuration settings at FreeLists.org - By sending a message to: opendtv-request@xxxxxxxxxxxxx with the word unsubscribe in the subject line.