What is SDV? SDV stands for Switched Digital Video, a scheme where not all TV channels are broadcast out from the cable headend to the homes that it serves all of the time. This is attractive to cable companies, because they can offer more TV channels than their cable plant has the bandwidth to broadcast. For example, your cable company may have 10 different channels in your lineup, but only 5 physical channels to send them from the headend to the houses they service. This requires a cable box that can communicate back upstream to the headend and say “I would like to watch ESPN2HD now” and then headend would take that request, assign it to a frequency and then tell the cable box “ESPN2HD is available on xxx,xxx kHz” What does this mean for the Series 3, Tivo HD and TiVo Premiere? With out an additional Tuning Adapter supplied from the provider, the Series 3, Tivo HD and TiVo Premiere is not able to communicate upstream to the cable headend, so it cannot send the request for channels that are assigned to SDV. Users of the S3 and THD will not be able to watch or record any of these channels. Which channels will be converted to SDV? Traditional methods send every channel to everyone, and if no one on your head-end is watching that channel, the bandwidth is effectively wasted. SDV allows them to turn off that channel when it's not being watched so that another channel can occupy that bandwidth. If a channel is always being watched it will probably never be converted to SDV. So the less popular a channel is, the more likely it will be converted to an SDV channel. See this Multi-Channel news article. That being said, there are some providers who use SDV to deploy a very large number of channels, though. The solution The NCTA and TiVo worked together for over a year and finally the first working solution has reached TiVo owners in NJ on Comcast. The device from both Cisco and Motorola are called Tuning Adapters (formerly known as Tuning Resolvers) and connect via USB to the TiVo (9.4 or higher) and feature pass-through coax connections, so a splitter is not needed. So when you attempt to tune a channel delivered using SDV, the TiVo sends a signal via USB to the Tuning Adapter which sends the signal via coax upstream to the providers head-end. This turns the channel on and returns the tuning information back to the TiVo. In a demo at the Cable Show a few years ago I had a chance to play and was not able to notice any difference in speed when changing channels that were deployed with traditional QAM or SDV. Depending on the head-end there are two solutions, Motorola and Cisco (formerly Scientific Atlanta). If your operator hands out Cisco set-top boxes, then odds are they'll use a Cisco TA. The Cisco STA1520 The Motorola MTR700 Some providers are offering these for free, but some charge at first or after a few months. Here is TiVo's FAQ that address the Tuning Adapter. Here is Time Warner's FAQ about the Tuning Adapter. San Antonio TWC customers can pre-order their Tuning Adapter from here. Here is some of the history of the Tuning Adapter, formerly known as the tuning resolver: http://www.tivolovers.com/2007/05/10/mr-tivo-goes-to-washington Here is TiVo's official info on the adapter. http://tivosupport2.instancy.com/LaunchContent.aspx?CID=CBECF1B9-88DE-4B74-82C1-754C3260112A CableLabs press release about USB dongle http://cablelabs.com/news/pr/2007/07_pr_dcr_devices_112607.html NCTA and TiVo press release http://www.prnewswire.com/cgi-bin/s...11-26-2007/0004711019&EDATE=#linktopagebottom Of if you want to do something about it, report your missing channels to the FCC. http://www.fcc.gov/cgb/complaints_general.html What about FIOS? Right now, because of the fact that FIOS uses fiber optic cable to your house, FIOS has no plans to deploy SDV – they have instead chosen to invest in expanding their QAM RF overlay infrastructure and use IPTV for PPV and VOD. Where is SDV located right now? SDV deployments are changing very rapidly and impossible to track, in fact even most of the CSRs don't know if their company uses SDV and even if they do, not which channels. Tuning adapters are here to stay TiVo has asked the FCC to modify the rules pertaining to 3rd party CableCARD devices and eliminate Tuning Adapters. The proposed solution was to allow the TiVo to communicate via IP to the operators servers to perform the requests that are currently handled by the TA. This would've require that you have internet service from the same provider, but would eliminate a set-top box from the equation. TiVo claimed it was necessary to increase reliability and would reduce costs for the operators. The NCTA and its members claimed that the TAs are well accepted and supported and it is not necessary to make any changes. The FCC determined that it would rather not mandate a specific solution, but instead mandated the SDV channels work for CableCARD users and will be making it easier to report issues so that consumers could help enforce the mandate.