Time Warner Cable Tuning Adapter (ALL LOCATIONS) / Bugs & Issues

Discussion in 'TiVo Series3 HDTV DVRs' started by dolfer, Feb 26, 2009.

  1. dlfl

    dlfl Cranky old novice

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    Jul 6, 2006
    Dayton OH

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    It's not at all clear that the CATV plant is responsible for all or even most of the "SDV tuning failures" (in TiVo's). There is evidence to suggest it is a problem in the USB handshake between TA's and the TiVo, so it may be a failure of either of those devices, which I find easy to believe.

    If the CATV plant is at fault, I guess we should just tell TWC support "your plant is improperly engineered". :rolleyes: I'm almost tempted to make that call just to see what response I would get. :D
     
  2. kevin120

    kevin120 New Member

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    yes there is a is limitation of overall bandwidth in a SDV pool when the pool is peaking to the point of where they need to add more QAMs to the pool there is a SDV congestion issue pertaining to bandwidth. I find it funny that TWC added 22 HD channels since North Texas had the SDV pool expanded to 24 QAMs from 16.

    We got:
    Reelz Channel HD
    Ovation HD
    Hub HD
    Bloomberg HD
    E! HD
    Style HD
    Oxygen HD
    OWN HD
    Sportsman Channel HD
    Fox Deportes HD
    Halogen HD
    Showtime Extreme HD
    Showtime Next HD
    Showtime Women HD
    Showtime Beyond HD
    ThrillerMAX HD
    MoreMAX HD
    TMC Xtra HD
    GAME2 HD
    IFC HD
    MLB Strike Zone HD
    3D Special Events 2

    I have a feeling once Austin gets more SDV QAMs they should see the channels in the list above that they don't have added to the system shortly after the changes are made.

    Three likely channels to be added between july and august:
    MTV2 HD
    TV Land HD
    PAC-12 Network National SD/HD

    TWC has a deal to make all three of these national and MTV2 HD and TV Land HD are supposed to roll out nationally this summer on TWC.

    Also there are nowhere near 2000 homes per node in an SDV system let alone 1000 it is probably closer to 250-500 although several nodes might make up a SDV tuning service group.
     
  3. lrhorer

    lrhorer Active Member

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    If that were true, then more likely than not it would also impact non-SDV channels. The TA overwrites the channel map for all digital channels when it is functional. Moreover, a failure on the USB port would not result in a tuning denial. A tuning denial response means the TiVo has successfully contacted the headend host and the host has responded that there are no available QAMs.

    Have you ever seen the movie I, Robot with Will Smith? In the movie, James Cromwell's character, a hologram, keeps telling Will Smith's character, "You have to ask the right questions." Tell the CSR you need to speak with an engineer who knows how many nodes are in the city and how many subscribers, and how many tuning requests are serviced on average per hour.
     
  4. lrhorer

    lrhorer Active Member

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    This is rarely the case. When it is the case, a single SDV QAM per node in a city the size of Dallas or Austin can support hundreds of channels. Once again, it is the number of unique streams on a node that determines how many QAMs per node are required, not the number of channels offered by the CATV system. Reduce the number of subscribers per node (the CATV system hopes by increasing or re-organizing the number of nodes, not reducing the number of subscribers), and the number of channels that can be delivered increases exponentially.

    Yet again, this is rarely the case. It is certainly not impossible, but the issue is not bandwidth but the number of unique streams on a node.

    Um, OK. Eight linear QAMs can handle 16 channels. Eight SDV QAMs can handle many, many times that. The small number of channels they added clearly has nothing to do with the number of QAMs per node they added. Indeed, adding more SDV channels decreases (slightly) the number of necessary QAMs, since adding more channels decreases the penetration of the existing channels.

    I really couldn't say. I may be mistaken, but I think Austin has as many SDV QAMs as we do in San Antonio, and we have had those channels for ages. OTOH, I don't know the node loading in Austin vs. San Antonio, either.

    I never said there was. I explicitly said typically 400 - 1000, serving perhaps up to 3000 receivers, assuming an average of 2 dual tuner DVRs per subscriber and 3 subscribers for every 4 homes passed. That may be a bit high, but it is a good, round number.

    It depends on the CATV company. The lowest number I have ever heard quoted was 400 homes, or about 300 subscribers. It's possible some CATV companies have installed enough nodes to make the number as low as 250 homes or under 200 subscribers. That is an awfully small number, though. A 750 MHz system can pretty easily support at least 150 HD streams. I know for a fact some CATV systems pass as many as 1000 homes per node, especially in areas of low penetration. There is no point in adding more nodes if half the people in the neighborhood don't have cable.
     
  5. lrhorer

    lrhorer Active Member

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    It varies from city to city, but look in the TA diags and it will tell you. It might even vary from node to node or hubsite to hubsite. Here at my house it is 16.75 MHz. It's always going to be between 5 MHz and 40 MHz.
     
  6. dlfl

    dlfl Cranky old novice

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    Dayton OH
    OK, here is some evidence to consider:
    http://www.tivocommunity.com/tivo-vb/showthread.php?p=7963092
    I think what I call an "SDV Tuning Failure" is different from what you're calling a "tuning denial response".

    An SDV tuning failure, whether during manual tuning or when trying to start a recording, results in a black screen and the mismatch between frequencies shown for the channel in the Cable Cards (DVR Diagnositics) or the TA, as shown in the photos attached to the linked post. If it was a recording attempt the recording history says it failed because no video was present. If it's manual tuning, you get a blank screen -- forever or until you re-tune, e.g., channel up/down, upon which it usually tunes OK.

    Then there is the other type of failure (denial ?) which, if tuning manually, results in a message saying to press select to try again -- which usually works. I don't know what happens with this type failure when it is trying to start a recording.

    I get both types of failure occasionally when manually tuning. I lose 1 to 3 recordings a week. In both cases the failures occur only on SDV channels.
     
  7. kevin120

    kevin120 New Member

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    I find it interesting that you keep mentioning that a single QAM per node can support 100s of channels that is wrong 10 channels max at a time on each QAM per node with 100s of unique QAM channel muxes throughout the system due to customer requests but the cable company only does about a 2:1 ratio of channels per QAM so if they reclaim a QAM with 10 channels they utilize that QAM with 20 SD SDV channels not all at once so if you have 200 SD switched you are going need 10 QAMs to handle the load and if you add HD channels to the mix they have a 6:1 QAM ratio so for every QAM that is reclaimed with 3 HD channels you can put 6 SDV HD channels in their place per QAM. So if you have a 100 SDV HD channels divide by 6 and you get the maximum QAMs you need for HD only but TWC squeezes in more channels per QAM in the pool so yeah they need 24 SDV QAMs to keep up with the growing number of HD channels being switched and more tuners being added.

    These should be the new SDV QAMs come June 26th in Austin:
    585MHz
    591MHz
    597MHz
    603MHz
    609MHz
    615MHz
    621MHz
    627Mhz
     
  8. dcstager

    dcstager 1st Gen Tivo Owner

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    Skagit...
    Great discussion. But if fewer HD channels are SDV, is my point about there being fewer tuning failures reasonable? I just want the Tivo to work. I hate missing the recordings. I'm getting more and more failures lately and it's just fortunate that the deep cable channels rerun the shows many times so I get my shows, but now always the first run. Some deep cable shows are one time only and I just hate looking through the recording history and seeing the "video was not available" message.
     
  9. dlfl

    dlfl Cranky old novice

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    Dayton OH
    The question is are your current tuning failures all on SDV channels? If so then it's likely having more channels on SDV will result in more tuning failures.

    Here is how you tell a (successfully tuned) channel is SDV, using your DVR Diagnostics and Cisco TA tuning adapter diagnostics screens:
    http://www.tivocommunity.com/tivo-vb/showthread.php?p=8024241#post8024241
    You get the frequency of the channel(s) from DVR Diaganostics (cable card) and use those to ID the channels in the TA info.

    You can also try to get a list of SDV channels from your TWC customer service. Good luck with that -- and don't trust it even if you do -- based on my experience.
     
  10. dcstager

    dcstager 1st Gen Tivo Owner

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    Skagit...
    Sorry, I'm not being clear in my question. I record mostly HDTV channels and a few SDV channels. Most, but not all my tuning failures are on SDV HDTV channels. I've had blank video on FOX and ABC local HDTV channels once each as well. But I'm hoping the move of more HDTV channels away from SDV will generally be a good thing and I'll miss fewer recording.
     
  11. kevin120

    kevin120 New Member

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    They are not going to be moving channels away from SDV instead they are adding bandwidth to the SDV frequency range so that there are less issues with channels being blocked. Dallas had this done last year and they reclaimed over 8 frequencies to add more bandwidth for SDV and VOD as they added 8 QAM carriers to SDV and 4 QAM carriers to VOD in North Texas. TWC in Austin is going be using the reclaimed bandwidth for SDV channels not moving existing SDV channels off of the SDV servers.

    TWC is going to be doing this in most of the state:
    Corpus Christi date TBA
    Austin June 26th
    Waco June 26th
    Rio Grande Valley June 19th
    El Paso August 21st

    From the looks of the tuning problem dlfl might be on to something about the tuning adapter because in North Texas we have the Motorola MTR700 tuning adapters and I don't hear about missed recordings also these tuning adapters never did have the problem with the blinking green light.

    I personally have motorola DCX cable boxes and never have recordings that are blocked due to SDV channels so maybe it is a issue on the Cisco tuning adapter connection to the Tivo.
     
  12. lrhorer

    lrhorer Active Member

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    Industry norm rate shaping is 12 SD channels, 6 SD + 1 HD channel, or 1 SD + 2 HD channels.

    SDV hypothetically allows a completely unique set of channels to be served on each and every QAM across the city. Now, in reality there will be widespread duplications of individual streams across the city, and that must be taken into consideration in capacity management, but the number of possible channels deployed is without limit.

    I seriously doubt that. There is no need. With SDV, one can easily manage 20:1 or more. Indeed, the local TWC franchise has an 850 MHz system with 72 analog channels still on tap. That leaves at most 343 MHz, or 57 QAMs to deliver all their digital channels. They supply 573 video channels, with 97 full time HD channels and over a score of On Demand HD channels. That amounts to at a minimum an equivalent of 60 linear HD QAMs and 32 linear SD QAMs. After adding in services like start-over and IPPV, that number probably nearly doubles.

    That is not industry norm rate shaping, nor is it TWC's policy, at least here in San Antonio, and I have the recordings to prove it. The HD channels frequently average 18 Mbps, and that would be impossible with 3 HD channels per QAM. Some CATV providers have indeed crammed 3 HD channels per QAM, but doing so has generated a significant amount of complaints about PQ in those systems.

    One can deliver vastly more than that. Again, there is no hypothetical limit to the number of channels a CATV company can deliver over SDV. As long as the number of unique HD videos per node does not exceed twice the number of SDV QAMs and the number of unique SD videos does not exceed the number of QAMs, the available palette of channels has no theoretical limit.

    What exactly is it, do you think, that puts a limit on the number of SDV channels that can be offered (not delivered, offered) city-wide per QAM?
     
  13. lrhorer

    lrhorer Active Member

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    That is no doubt true. As long as the upgrade does not require additional overall bandwidth, adding a QAM is a fairy inexpensive way of delivering more service, especially On-Demand and trick-play features like start-over. The most obvious means of doing this is to convert an analog carrier to SDV.

    I never have any problems with tuning denials or tuning failures here in San Antonio, either, and I have three Cisco TAs. I do occasionally have problems with total lock-ups that completely drop either all SDV channels, all encrypted channels, or occasionally all channels, period. None of these are the result of bandwidth limitations, and clearling the issue requires either pulling and re-plugging the USB cable, rebooting the TA, or in the latter case rebooting both the TA and the TiVo.
     
  14. dcstager

    dcstager 1st Gen Tivo Owner

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    Skagit...
    With the Cisco lawsuit, maybe TW can return the whole bunch as defective and replace every Cisco tuning adapter with a Motorola version?
     
  15. lrhorer

    lrhorer Active Member

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    They would have to tear out and re-build their entire data infrastructure, including their server farms and all their STBs and DVRs.
     
  16. Teeps

    Teeps Well-Known Member

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    Torrance,Cal...
    So are you saying that tuning adapters are not built to a single standard?

    I'm confused... on more than one level with this particular SDV discussion.

    A link to some reading would be welcome.

    Thank you.
     
  17. unitron

    unitron Well-Known Member

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    The Cisco ones work with Cisco stuff "upstream" and the Motorola ones work with Motorola stuff.

    Like they say, standards are a wonderful thing because there are so many of them.:rolleyes:
     
  18. lrhorer

    lrhorer Active Member

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    Nope. There are no SDV standards whatsoever, but there are two sets of competing proprietay protocols: Cisco and Motorola. The FCC never required a standard, so CableLabs never wrote or implemented one. There have been some proposals, namely DCR+ and tru2way, but so far nothing has really gelled. The CE manufacturers are pushing hard for DCR+, but CATV companies would rather have their gonads removed with a baseball bat. The CE manufacturers are uninspired by tru2way, and many of us consumers hate tru2way, including me. Big Brother needs to keep his pointy nose out of my business and allow me to run whatever software I like on a machine that I own. TiVo is bad enough. Tru2way (specifically OCAP) is legally sanctioned evil.

    Well, as far as the SDV standard, it is a little hard to link to something that does not exist. For the rest, Google is your friend. Try here for starters.
     
  19. lrhorer

    lrhorer Active Member

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    Whihc is one big reason why a TA is required in the first place. If there were a single standard, the device could be universally modified to support it. As it is, a TiVo designed to work on a Cisco system would not work on a Motorola systrem, and vice-versa.
     
  20. Teeps

    Teeps Well-Known Member

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    Thanks lrhorer,
    Your answer tells me all I need to know about the evil that IS SDV.
    Or, how to virtually stuff 10 pounds of crap in a five pound bag.

    If verizon ever comes to my part of the city... say good bye to cable.
     

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