Future internet speeds - must suck to be AT&T...

[kjnorman]

Thank you Loadstar, you explained it much better than I did :rock:

[tencom]

Uh, no. You might be thinking of some of the diagnostic screens that you see on your digital cable box that show stuff like an IP address and other TCP/IP related information. This is strictly how for the "addressable" part of the cable box - it's what it uses to get the cable guide and other information, and how the cable company contacts the box. It has nothing to do with the video.

Digital cable channels contain MPEG-2 MP@ML compressed video transmitted via QAM 256 modulation over the coaxial line. HD cable channels are also transmitted via QAM 256 - not sure what they used to compress the video. I think it might be MPEG-2 MP@HL.

IPTV is a completely different beast. Instead of modulating the different channels to run across a coaxial line like cable TV does, the whole thing is one giant TCP/IP network. The "channels" are just multicast H.264 video streams that your box connects to when you tune to that channel. It's really not much different than if you were to load up Windows Media Player or RealPlayer on your computer and connect to a live stream - the set top box just makes it "feel" more TV-like by automating and hiding all the process of connecting to the different streams.

Cable television uses the same format for both there  Internet services such as Roadrunner and digital cable television. They both uses  packets with an destination address at the header which is consistant with the "Internet Potocol"
 when your refer to QAM256 it only refers to the type of modulation thats being enployed to transfer the data Were cable is using the MPEG 2 format for digital television and Uverse is using the MPEG 4 format no matter what digital compression format is beig employed  they still are using packet switching to divert the packets to the right destination.

[tencom]

Fiber itself really isn't that bad... and with the sharp increase in costs of copper, the difference in cost is shrinking.

The major cost difference is the labor involved, the equipment needed, and the training for your employees to know how to properly install, terminate, and repair fiber. There's lots of expensive, very technical equipment required to properly handle fiber optic line, and if it isn't installed properly, it don't work.

As I understand it,  Verizon is spending 19 billion dollars on there FTTH FIOS system and ATT is spending about 6 bllion for there FTTN Uverse system both pass about the same number of homes. Quite a large difference in cost. Maybe thats why no other corporation is following Verizon lead.

[TPK]

As I understand it,  Verizon is spending 19 billion dollars on there FTTH FIOS system and ATT is spending about 6 bllion for there FTTN Uverse system both pass about the same number of homes. Quite a large difference in cost. Maybe thats why no other corporation is following Verizon lead.

I think the reason why fiber to the home costs so much more is due to the replacement of the infrastructure that has to be put in to wire up each house with fiber, as opposed to leveraging the existing coppor wire that is already running to everyone's home, and through everyone's back-yard....  I think thats where the cost difference comes in...  Fiber has to be put in place, but coppor is already there, so coppor is cheaper...   Of course fiber is better (much much much better)...

Also you have the legal hassle of dealing with the state and local municipalities and their backwards zoning restrictions whenever you try to push through some new technology that requires building something...  Lawyers fees, bribes to local politicians, kickbacks to various unions and other groups, all add to the cost of putting a new infrastructure in place....

If you compare fiber to something like coaxial cable, even if it did cost more per foot to run fiber than coax, I bet that the costs would still even out, since you can run a fiber for hundereds of miles before you have to re-amp and repeat the signal, wheras with coax you have to constantly put in repeaters to amplify and repeat the RF that is being passed through the wire...  The higher the frequencies, the more you have to amplify, etc...  That costs money in installation and in maintainance, which I imaigne outweighs the costs of fiber...

Another thing I don't understand is why u-verse would opt to re-encode to mpeg-4, when they could have waited to get their DSL speeds up to the point where they could deliver mpeg-2 straight to the home, without having to go through the trouble of re-encoding it..    I suppose there is a lot of cost to that (since they appear to be doing it so poorly)....

Isn't the entire broadcasting industry on the mpeg-2 standard???  I know at least broadcast television is but how does it work at the back-end for all those digital cable stations??  Arent they delivered to the cable companies via satellite in an mpeg-2 format???  Wouldn't it be easier, cheaper, and be better quality if U-verse just passed us their mpeg-2 directly, rather than having to re-encode it to mpeg-4 and give us that??

I know that they are trying to conserve on bandwidth, so they can deliver to us more channels at a given time, but wouldn't it make sense then to give us a mixture of mpeg-2 and mpeg-4 (hell, make 2 sets of HD channels, one high-qualtiy and one mpeg-4 quality)...  Then they could stem off all the picture quality complaints and since they really won't have to re-encode anything (since its all delivered to them in mpeg-2 anyhow) it wont cost them that much (if anything) to do it....

Or am I wrong about how the cable industry works???   I wish I knew....

[LoadStar]

Cable television uses the same format for both there  Internet services such as Roadrunner and digital cable television. They both uses  packets with an destination address at the header which is consistant with the "Internet Potocol"
 when your refer to QAM256 it only refers to the type of modulation thats being enployed to transfer the data Were cable is using the MPEG 2 format for digital television and Uverse is using the MPEG 4 format no matter what digital compression format is beig employed  they still are using packet switching to divert the packets to the right destination.

I'm sorry, but your understanding of how cable television operates is incorrect.

There is no packet switching going on with digital cable at this time. Your cable line contains all the channels available on digital and analog cable that are available to everyone else in the Milwaukee Time Warner area. Every channel is modulated to a specific frequency across the cable physical plant. That's the reason that Time Warner is limited in what channels they can add... there's a specific limit to the frequency bandwidth available.

Switched Digital Video does move closer to how IPTV behaves, but not how it is implemented. With SDV, the cable box "asks" the headend systems for a specific channel. The distribution node servicing a neighborhood then dynamically allocates a specific frequency and activates the requested channel on that frequency. It's still technically not packet switching... between the headend and the distribution node, everything remains the same as it is now, with every channel being sent out to every distribution node. The distribution nodes just are upgraded to be more intelligent, turning off certain channels that aren't being watched.

The only possible common thread between cable and IPTV is that both use a MPEG compression algorithm... and not even the same MPEG compression method, so even that's a tenuous thread between the two. Other than that, there is really absolutely no similarity between IPTV and Cable TV.

[LoadStar]

To add/clarify/simplify:
- IPTV: H.264 packets are encapsulated into IP packets, which are then transmitted as any other IP packets across a TCP/IP data network.
- Digital cable: MPEG-2 packets are modulated (not encapsulated) to a specific frequency, then transmitted on that frequency on the HFC (Hybrid Fiber Coaxial) radio frequency "network" (not a data network - just a series of interconnected wires that contain a radio frequency signal).

Because there's no encapsulation with cable TV, there's no packet switching going on. It's all RF (Radio Frequency) -- even Road Runner, which is an IP service that has been modulated into a radio frequency signal.

Or in other words, hopefully more simple than any of this:
- IPTV is a data network that contains video as one of it's components.
- Digital cable is a radio frequency service that contains data as one of it's components.

[tencom]

Video On demand uses Packet switching, how else can they direct an event to your TV  and the program guide is also viewer requested. both  interact with the viewer.  With video on demand you can conrol the pace, of a recorded video just as you can with a DVD or VCR thru your cable  remote.

[LoadStar]

Video On demand uses Packet switching, how else can they direct an event to your TV  and the program guide is also viewer requested. both  interact with the viewer.  With video on demand you can conrol the pace, of a recorded video just as you can with a DVD or VCR thru your cable  remote.

With Video on Demand, when you order the video via your cable box, it sends the order for a specific program back to the headend. The headend then begins transmitting the video modulated to a newly allocated QAM channel, which is then transmitted. Again here, there is no packet switching - it's strictly RF modulated digital video.

The ability to order the program, fast forward, and rewind is all done via IP, true, but just as with Road Runner, it's IP packets that have been modulated to an RF signal and sent back to the head end. The video remains strictly RF modulated MPEG-2 video.

[MDR]

With Video on Demand, when you order the video via your cable box, it sends the order for a specific program back to the headend. The headend then begins transmitting the video modulated to a newly allocated QAM channel, which is then transmitted. Again here, there is no packet switching - it's strictly RF modulated digital video.

The ability to order the program, fast forward, and rewind is all done via IP, true, but just as with Road Runner, it's IP packets that have been modulated to an RF signal and sent back to the head end. The video remains strictly RF modulated MPEG-2 video.

 I've been researching buying a new HDTV on some forums. The one's with QAM tuners will receive  VOD on your node even though you haven't ordered it ( provided it's a clear QAM channel) . They mention how people (the one's who actually ordered it) would keep rewinding and fast forwarding while you lurked and watched their show.

If your TV has a QAM tuner built in, bypass your box and hook up your Ant. In  directly to the cable wall outlet. Do a channel scan and see what get. I,m not sure what's clear QAM on TWC but you will see all available. Of course if VOD or PPV are clear QAM these channels will come and go as others view them so you would have to rescan to get current offerings.

Mdr

[picopir8]

I highly doubt it would be this easy.  While the channel would be available, I suspect that the content delivered on that channel would be encrypted similar to channels on the HD package.

[LoadStar]

I highly doubt it would be this easy.  While the channel would be available, I suspect that the content delivered on that channel would be encrypted similar to channels on the HD package.

You're right, usually it should be encrypted.

However, I have indeed seen exactly what was described - I scanned through the stations, and stumbled upon one showing a Showtime On Demand program on some frequency/channel that didn't match up with a known Clear QAM channel. I watched it for a bit as the person played it for a while, then rewound and replayed a portion of the program.

More than likely if it ever comes through in the clear, it's a glitch in the system, I'd suspect.

[tencom]

TWCs Video On Demand  was sent unencrypted until about June of 2004 when encrpytion was initiated. I still have in my computer files, video samples of complete VOD channels The channels that TWC used for VOD were 80,81, and 82 and some of the video material that were ordered from this node area are inapproiate for children.