I agree with CNET's "Five reasons to not buy a CableCard".
There's a long and sordid history in the Cable Industry behind the CableCard. From the outside it seems like a fine idea, but none of the insiders wanted it, so it happened slowly. Now that it's here, it's obsolete as the version available now only supports 'one-way' video services, i.e., traditional broadcast TV. EPG, VOD, built-in PVR, and more interactive services, all require two-way communication, which is not in this version.
There are specs in CableLabs for the two-way version, but it's not clear if they're finished or even workable. And more likely the existing specs would be trumped by the industry's NGNA -- Next Generation Network Architecture effort (see http://www.cabledigitalnews.com/ngna/ngnaprimer.ht ml for an NGNA primer). The cable video industry is a bit peculiar to the computer and networking crowd because there is basically only proprietary systems. There are standards-based components and approaches, but by the time a whole system is built, Set Top Boxes are not interoperable across multiple systems. The the kicker: with mostly analog video on cable systems, usually almost all the bandwidth was tied up with programming. That left no available spectrum to introduce a different, competitive system. Once a vendor got into a city, the operator never changed over to a differerent vendor in that city, because the switching cost was too great.
There's a chance this will change, due mostly to digital TV requiring less bandwidth, pent-up demand for new technology (VOD & PVR primarily), and the great success cable has had with DOCSIS-based Internet Access (they make a ton of money on it!) leading to some appreciation for open standards and interoperability. We'll see.
Uhh, the downstream most certainly *is* shared. Read the DOCSIS spec at the SCTE web sight (http://scte.org/documents/pdf/SCTE2312002DSS0209. pdf). Typical deployment these days is one 6Mhz RF channel per 2000-3000 homes passed serving area, with 27Mbps downstream in the channel. The MC16 card has one downstream and 6 upstreams. The upstreams typically serve a 500 Home passed section of the larger serving area.
These are typical numbers but any particular location may be significantly difffernt. If an area gets too busy it's pretty easy to deploy more bandwidth by using more 6Mhz RF channels or sharing the downstream over a smaller area.
Wood's Hole Oceanographic Institute (whoi.edu) has made some very nice animations illustrating the ocean currents, including what happens when increasing amounts of fresh artic melt water enter the North Atlantic -- the Gulf Stream is blocked, and the prevailing westerly winds are no longer warmed, and then Europe enters a new little Ice Age, just like 1400-1850.
Slashdot Mirror
...I heard it called the Foreplay. It's not clear what happens after that...
-- Jim
I agree with CNET's "Five reasons to not buy a CableCard".
t ml for an NGNA primer). The cable video industry is a bit peculiar to the computer and networking crowd because there is basically only proprietary systems. There are standards-based components and approaches, but by the time a whole system is built, Set Top Boxes are not interoperable across multiple systems. The the kicker: with mostly analog video on cable systems, usually almost all the bandwidth was tied up with programming. That left no available spectrum to introduce a different, competitive system. Once a vendor got into a city, the operator never changed over to a differerent vendor in that city, because the switching cost was too great.
There's a long and sordid history in the Cable Industry behind the CableCard. From the outside it seems like a fine idea, but none of the insiders wanted it, so it happened slowly. Now that it's here, it's obsolete as the version available now only supports 'one-way' video services, i.e., traditional broadcast TV. EPG, VOD, built-in PVR, and more interactive services, all require two-way communication, which is not in this version.
There are specs in CableLabs for the two-way version, but it's not clear if they're finished or even workable. And more likely the existing specs would be trumped by the industry's NGNA -- Next Generation Network Architecture effort (see http://www.cabledigitalnews.com/ngna/ngnaprimer.h
There's a chance this will change, due mostly to digital TV requiring less bandwidth, pent-up demand for new technology (VOD & PVR primarily), and the great success cable has had with DOCSIS-based Internet Access (they make a ton of money on it!) leading to some appreciation for open standards and interoperability. We'll see.
Uhh, the downstream most certainly *is* shared. Read the DOCSIS spec at the SCTE web sight (http://scte.org/documents/pdf/SCTE2312002DSS0209. pdf). Typical deployment these days is one 6Mhz RF channel per 2000-3000 homes passed serving area, with 27Mbps downstream in the channel. The MC16 card has one downstream and 6 upstreams. The upstreams typically serve a 500 Home passed section of the larger serving area.
These are typical numbers but any particular location may be significantly difffernt. If an area gets too busy it's pretty easy to deploy more bandwidth by using more 6Mhz RF channels or sharing the downstream over a smaller area.
Wood's Hole Oceanographic Institute (whoi.edu) has made some very nice animations illustrating the ocean currents, including what happens when increasing amounts of fresh artic melt water enter the North Atlantic -- the Gulf Stream is blocked, and the prevailing westerly winds are no longer warmed, and then Europe enters a new little Ice Age, just like 1400-1850.
See Abrupt Climate Change: Should We Be Worried?
and Abrupt Climate Change.
-- Jim