• Why does x area have more HD channels than my area?
• What does the June 12th digital transition mean to me?

(back)More HD is coming. What, when and where is up to each region. Many area's need to work on "reclaiming" some spectrum which can be used for more HD launches. Reclaiming bandwidth can come from migrating an analog channel to digital, or re-optimizing a multiplex so that 3 HD channels can fit in the same space a regular analog channel would fit. Migrating HD from the normal 2:1 to a 3:1 mux would be unnoticed for most people since the channel mapping stayed the same, it was just the source that changed. Each analog channel slot can contain up to 12 (soon to be 15 with new grooming) SD digital channels. Many Comcast systems have over 2/3rds of their bandwidth dedicated to Analog channels. It is vital that these channels are migrated to digital for better resource allocation over the RF network.

With any channel launch or frequency change, there is a LONG drawn out process that must be followed. The FCC requires notice to be given for any channel changes or removals/repositions. Corporate must approve any channel change requests and then there is the marketing side with contracts, timing and advertising. For any MAJOR changes Comcast is required to give 30 days notice, and just getting that out can sometimes be troublesome. One way around a 30 day notice in a channel add would be a soft launch. A soft launch is when channels will appear 'out of the blue'. Usually a week or two later there will be an ad in your local paper saying that the channels will be available 30 days from now, but you can enjoy a 'free preview' today.

It's also because of this required notice, along with the mis-match of channel maps, channel locations, etc, between all the various systems throughout their history of acquisitions that you end up having the channels all over the place. Comcast tries to stick things where they can find room. A region may have 30+ channel lineups to handle each with it's own bandwidth limitations. Imagine playing a really hard game of Soduku. If you simply make a change to a multiplex in one area, it's likely to affect 30 other area's because they are pulling the video from the same multicast IP address. Everyone must be coordinated and on the same page. Adding/changing channels can be a very messy and tedious project.

Definitions:
Multiplex - communicates two or more signals over a common channel
Mux - Shorthand for Multiplex. 2:1 Mux means 2 signals are broadcast over a common channel. 3:1 means 3 signals are broadcast over a common channel, etc.
RF - Radio Frequency
SD - Standard Definition (up 480i resolution)
HD - High Definition (1280x720p or 1920x1080i resolution)
Multicast - addressing is a network technology for the delivery of information to a group of destinations simultaneously using the most efficient strategy to deliver the messages over each link of the network only once, creating copies only when the links to the multiple destinations split.
Bandwidth - The width, usually measured in hertz, of a frequency band; Of a signal, the width of the smallest frequency band within which the signal can fit; A measure of data flow rate in digital networks typically in bits per second; The capacity, energy or time required

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by cypherstream
last modified: 2009-05-22 15:29:36

(back)Below you can find the official Comcast website concerning the Digital Transition:
»www.comcast.com/dtv/homepage.html

The June 12th digital transition will have absolutely NO EFFECT on your Comcast service! This date is a Government mandate that only affects over the air broadcasters. Cable systems are using their own private RF spectrum over fiber and coaxial cable. Comcast will do what they want with their spectrum when they want. Expect Comcast to take advantage of the situation by attracting new customers signing up to basic cable because their over the air antenna no longer works. Comcast will also take advantage to run additional outlets in homes where some rooms relied on rabbit ears while only the primary room or two had cable.

You may of heard of Comcast digital migration website seen here: http://comcastdigitalworld.com/ or »www.comcast.com/digitalnow It's true that digital signals are a much more efficient way of transmitting video. Remember, with every one analog channel removed, about twelve (or more) digital channels can be added. With the much higher bandwidth requirements of HDTV channels, each analog removed will also allow a system to add three additional HD channels or an additional 38mbps of data.

Because of the efficiency with the digital transmission, Comcast will (at their pace) migrate channels from analog to digital. Please note that they will offer discounts on set top boxes and other promotions in migration area's. Remember this is at Comcast's own pace, and has nothing to do with the 6/12/09 date that the FCC set for local broadcasters. Keep an eye on your monthly billing statement or local newspaper for details.

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by cypherstream edited by sansri88
last modified: 2009-02-13 16:32:13

• What is Interactive TV or “iTV”?
• What do “ETV” and “EBIF” refer to?
• What capabilities are available for ETV applications?
• What is tru2way (OCAP) in relation to Interactive TV?

(back)Interactive TV (ITV) is an umbrella term used across many industries and countries. It is not specific to any technology and can include EBIF, tru2way, and a multitude of other technologies deployed around the world. Think of ITV as encompassing any user experience that might be enabled on television beyond the traditional guide/DVR/VOD interface. One of the many features of Comcast's ITV is Caller ID on Screen. Currently Comcast ITV features only work on Motorola based equipment. SA/Cisco set tops are slated to receive ITV features later this year. New ITV features are in development and testing, and will be rolled out on a market by market basis.

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by cypherstream

(back)ETV stands for Enhanced Television. EBIF is a technical term (Enhanced Binary Interchange Format) associated exclusively with the CableLabs open standard specification. The EBIF spec allows apps to be written once, and run everywhere when the standard is followed. EBIF is a ‘lightweight’ technology that can run on even "low-end" set-top-boxes like the widely-deployed Motorola DCT 2000.

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by cypherstream

(back)ETV applications are typically bound to programming on cable networks allowing for interactive overlays that correspond to the video content. The capabilities of these applications include:

* Graphic Overlays - Present on-screen widgets allowing subscribers to interact using their set-top remote control
* Synchronized Delivery - Insert applications into programming (either pre-produced or live) to synchronize interactive overlays with the broadcast content
* 2-way communication - Send form posts from the set-top box through the cable head-end to a response server via HTTP. This allows for applications such as voting/polling and advertising requests for information (RFI)
* Telescoping to VOD - Interface with the video on demand layer to jump from linear programming to VOD assets
* Dynamic Data - Use existing data feeds to update interactive applications with news, programming info, product info, polls, etc.
* DVR Support - Set recordings for episodes or series on DVR boxes.
* Personalization & Targeting - Store user data to create customized experiences

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by cypherstream

(back)Tru2way is cable’s next-generation hardware/software platform that enables advanced interactive TV applications. Tru2way complements EBIF in that it is a more advanced technology that runs on tru2way certified devices, whereas EBIF uses a thin-client approach that is compatible with the lowest-common-denominator of set-top boxes in the field today. For Comcast, EBIF applications will also run on tru2way devices.

For more information see:

* CableLabs OpenCable FAQ
* OCAP/EBIF Developer Network

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by cypherstream

• Useful external links
• Comcast Motorola Equipment

(back)How to download unencrypted programs from your DVR to your PC?
»www.avsforum.com/avs-vb/showthre···t=403695
It only applies to unencrypted channels, aka clear-QAM Channels. Usually, those are the broadcasting channels and the expanded analog channels.

Comcast HDTV section on avsforum.com:
»www.avsforum.com/avs-vb/showthre···t=424081
Avs Forum contains discussion on many topics for the A/V enthusiast, like TV programming, detailed discussions on hardware(cable boxes, DVRs). This is the main Comcast HDTV page on the avsforum.

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by Travelfan1

(back)The following websites pertain to information regarding the Motorola equipment.

How to use a Motorola DVR

I-Guide manual (PDF)

Motorola Customer Premises Equipment (Set-Tops)

There are a few series of Motorola set tops.
The low-end Motorola 68k models include the DCT-1700, 1800, and 2000. Due to the limited memory and processing power, these models have a reduction in amount of guide data that is stored in memory. While they can still support simple ITV applications, the local area will need to employ guide filters to these set tops that prevent them from loading a full set of guide listings. Also ITV transparency elements are not available, as well as video scaling. The general performance (navigation and channel changing) is much slower. These set tops are SD capable ONLY. Back in the early days of HD, a Motorola HDD-200 sidecar box could be connected to the data port on DCT-2000's to enable HD decoding.

The mid-range Motorola MIPS-32 models include the DCT-2500, DCT-700, DCH-70, DCH-100, DCH-200. These models are noticeably faster than the older 68k models. They support video scaling, which means you will see the current channel scaled down to fit in the upper right corner of the guide. These set tops are SD capable ONLY.

The high-end Motorola MIPS-64 models encompass a larger subset of equipment:
DCT-5100 Original HD set top (DVI Interface)
DCT-6200 Most popular HD set top (DVI Interface)

DCT-6208 Single Tuner HD DVR (DVI Interface) (80GB)
DCT-6412/6416 Dual Tuner HD DVR (DVI Interface, except for Phase 3 set tops have HDMI) (120GB/160GB)
DCT-3412/3416 Digital only Dual Tuner HD DVR with HDMI (120GB/160GB)

DCH-6412/6416 Cable Card Dual Tuner HD DVR with HDMI (120GB/160GB)
DCH-3412/3416 Digital only Dual Tuner Cablecard DVR HD DVR with HDMI (120GB/160GB)

DCX-100 MPEG4 compatible SD Digital only set top with 1GHz tuning (M Models support MoCA) and Cablecard
DCX-700 Small Form Factor MPEG4 compatible HD Digital only set top with 1GHz tuning (M Models support MoCA) and Cablecard
DCX-3200 MPEG4 compatible HD Digital only set top with 1GHz tuning (M Models support MoCA) and Cablecard
DCX-3400 MPEG4 compatible Digital only HD DVR with 1GHz tuning (M Models support MoCA) and Cablecard

The latest DCX models have the most available memory and processing and can be configured with as much as 512MB RAM, and 320GB Hard Drive (DCX-3400). The DCX-3200 and DCX-3400 also allow native HD resolution pass-through, video sharpness post processing, and Dolby Digital Plus. The DCX models also run much cooler than their DCH / DCT cousins. All guide and ITV features will work on the MIPS-64 based architecture.

The Motorola naming scheme is as follows:
DCT series - integrated security (no cable card slot)
DCH series - separable security (cable card pre-installed)
DCX series - separable security (cable card pre-installed), Advanced functions (Processor, Memory, MoCA, MPEG4, Dolby Digital Plus, 1GHz Tuning)
QIP series - integrated security (no cable card slot), MoCA and IPTV functionality paired with traditional QAM tuning. This series is only used for Verizon Fios.

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by cypherstream
last modified: 2010-02-17 12:35:59

• If I buy a digital cable box from a web site like EBay, will it work?
• What do I need to get digital cable?
• What do I need to receive HD service?
• Cable Card, TiVO, and Comcast STB: What's best for me?

(back)More likely than not digital cable boxes for sale on Ebay or sites like Craigslist, and others, were stolen. Comcast will not activate stolen boxes bought off the internet.

If you have bought one, you should return it to the closest Comcast location and pick up a legal box from that center.

If you want digital cable service, you should rent a cable box from Comcast or purchase a TiVO or a Moxi unit.

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by sansri88 edited by Travelfan1
last modified: 2008-12-16 10:47:44

(back)First, congratulations on making the step forward into the digital realm!

In order to receive digital cable from Comcast, it is recommended that you rent a cable box from Comcast.

If you wish to order HD service, please see this question.

For digital service in standard definition, you need to get one of the following cable boxes from Comcast. Note, you may also order DVR service. In that case, you may receive an HD DVR (if no SD-DVRs are available).

In Motorola areas, you may get:
-DCT700
-DCT2500
-DCH100
-DCH70

In Scientific Atlanta/Cisco areas, you may get:
-Explorer 940
-Explorer 8300 DVR
-Explorer 8240 DVR
-Explorer 8000 DVR
-Explorer 4250C
-Explorer 4250
-Explorer 4240C
-Explorer 4200
-Explorer 3250
-Explorer 3200
-Explorer 3100
-Explorer 3000
-Explorer 2200
-Explorer 2100
-Explorer 2000
-Explorer 1850
-Explorer 1840
-Explorer 1800

In certain systems, Pace set top boxes may also be available. Please inquire at your local office for the availability of the aforementioned cable boxes.

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by sansri88

(back)To receive HD service from Comcast, you need the following equipment:

-An HD capable television
-High Definition set top box, from either Comcast or a 3rd party, or;
-Cable Card slot in television, or;
-QAM tuner in television.

In order to access all the HD channels on your service level, you must have a set top box or a cable card slot in your TV. A QAM tuner may only pick up your local channels in HD and nothing more.

High Definition boxes that are currently offered by Comcast are as follows:

In Motorola areas, the HD boxes that are offered are:
-DCT6200
-DCT5100 (Depreciated)
-DCT641x (DVR)
-DCT341x (DVR)
-DCH6200
-DCH641x (DVR)
-DCH3200
-DCH341x (DVR)
-PACE RNG110 (small black HD set top with no front clock display)

In Scientific Atlanta/Cisco areas, the HD boxes that are offered are:
-SA 8300HD (DVR)
-SA 8300HDC (DVR)
-SA 42x0HD
-SA 42x0HDC
-SA 3xxxHD

You may also purchase a TiVO or Moxi unit for use on a Comcast system. It does require a Cable Card from Comcast, which may need a truck roll for installation.

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by sansri88 edited by cypherstream
last modified: 2010-09-28 07:41:57

(back)When you get digital cable, you have several choices for service. Today, those choices consist of the (1) Comcast STB or DVR and (2) existing one-way CableCard devices like TVs, the TivoHD, and Moxi. Next year, customers in most markets will have another option: (3) CableCard devices with true2way. There are advantages and disadvantages to each solution.

With a Comcast STB/DVR, you receive all the SD and HD programming that you pay for, plus access to Comcast's On Demand and PPV services. Comcast is responsible for troubleshooting problems and replacing dead/defective equipment. Cost varies by market, but the typical premium over basic cable is $6 to $9 per digital outlet (includes one STB). HD adds $5-8, and the DVR adds another $13-$15 on top of that. Contact your local office for more information.

By using the Comcast STB/DVR, you are limited to whatever software and hardware capabilities that Comcast offers in your area. With the Comcast DVR software, you cannot remotely schedule recordings, you cannot download recordings to your computer, and you cannot remotely access the recordings stored on other DVRs in your home. Comcast does plan to add remote scheduling to their DVRs before the end of the year. In most markets, Comcast uses Motorola DVRs that do not support storage expansion beyond the built-in 20-30 HD hour capacity. In some markets, Comcast uses Scientific Atlanta DVRs that unofficially support external expansion with eSATA drives.

Existing CableCard devices like the TivoHD and Moxi receive all the SD and HD programming that you pay for, but they do not support Comcast's On Demand services or IPG; furthermore, some Comcast PPV content must be ordered over the phone. The TivoHD and Moxi provide their own program guide with 14-days of program information; they download this guide information from their servers used a wired or wireless connection to your home network. Advantages of the TivoHD and Moxi DVRs include superior DVR functionality, usability (ex: no remote lag, improved commercial skipping), up to six times the capacity (157 HD hours), support for external hard drives (up to 300+ HD hours), remote scheduling, and PC/Mac integration. Other TiVo features include multi-room viewing and the ability to download SD and HD recordings to your computer.

CableCards are essentially access cards; they plug into the device and authorize all of the channels you pay for. The TivoHD and Moxi both support dual tuners with a single CableCard (M-CARD). Comcast will provide one free CableCard as part of digital service, but additional CableCards will cost $1.50-$2.50/ea. If you have another Comcast STB/DVR in your home, or buy a second TivoHD, you may be assessed an additional "outlet fee."

You do not pay Comcast STB or DVR fees to use CableCard devices like the TivoHD and Moxi. The purchase of a TiVo or Moxi DVR typically results in lower monthly fees, but it takes years for that savings to offset the purchase price. People who buy a TiVo or Moxi typically do so because they want the improved DVR functionality, usability, and storage capacity. If you decide to buy a TiVo or Moxi, do so with the knowledge that that Comcast is not responsible for replacing dead/defective equipment (with exception to the CableCard).

TivoHD

The TivoHD DVR is available in 160GB (21 HD hours) and 1TB (157 HD hours) versions; it also supports 500GB and 1TB external drives. The 160GB and 1TB versions are $250 and $480, respectively, from Amazon.com. One of the following subscriptions is required for the first TiVo: $12.99/mo, $129/yr, $299/3yrs, or a one-time payment of $399. Subscriptions are discounted for each additional DVR. TiVo essentially gives you two options; you can (1) buy the box below cost at $250 and pay monthly or yearly subscription fees, or (2) pay $250+$399=$649 upfront and never have to worry about fees again.

Video Demos of TivoHD: Basic functionality | Netflix, Youtube, Video Podcasts | Viewing Computer Videos

Features:
• dual ATSC (OTA) / QAM (digital cable) / analog tuners
• support for MPEG-2, MPEG-4 AVC (H.264), and VC1
• program guide with filters, favorites, and fully customizable channel list
• 14-days of program information available on all channels (except ClearQAM channels), downloaded using your choice of ethernet, wireless, or a phone line.
• pause and rewind liveTV on both SD and HD channels
• record high-definition at 100% original quality
• record one HD channel while you watch another HD channel on the same box
• record two different HD channels simultaneously, while you watch a third, previously recorded show
• separate coax inputs for antenna and cable (split internally), with direct support for all digital cable channels without a cable box (using CableCard); will integrate cable and OTA in a single guide
• highly responsive "trickplay" functions (pause, replay, rewind, ffw, rew, 30sec skip, slow mo, etc) with no lag
• simple commercial skipping with 30sec skip (or 60x FF)
• name-based recording (aka "set it and forget it" recording), with ability to record only new episodes and ignore repeats
• always buffers both tuners (30 minutes each), so you can pause one live TV channel at a commercial, switch to another channel to watch for awhile, pause that, and then switch back to the first channel to resume where you left off, skipping commercials as you go
• when watching a liveTV program on either tuner, pressing record will save it from the beginning
• remembers where you left off in every recording, so you can resume watching from where you left off at any time
• conflict management with automatic rescheduling so programs missed due to three-way conflicts are automatically recorded the next time they air
• overlap protection to eliminate conflicts when three or more programs overlap by up to five minutes
• recorded history to tell you when a series program did not record and why (ex: because it was a repeat, because there was a conflict, etc)
• simple search by title (searches 14 days of listings)
• advanced search options with boolean operators, including the ability to automatically record all future programs matching a search
• multiple episodes of the same program are grouped into folders to reduce clutter and simplify navigation
• separate recorded lists and channel lists for adults and children (four-digit passcode required to switch from child list to adult list)
• undelete through a "Recently Deleted" folder at the bottom of the recorded list
• external drive expansion (with select 500GB and 1TB external drives)
• ability to download SD and HD recordings from the DVR to your computer in MPG format (note copy-protected recordings from premium movie channels cannot be downloaded)
• ability to view DVD rips and PC videos from your computer
• multi-room SD and HD viewing with another TiVo
• remote scheduling via the web and mobile phone
• variety of output modes, including "native" to output all formats as is without conversion
• 16:9 anamorphic SD output through s-video and composite outputs
• all SD and HD outputs active simultaneously
• support for internet videos / podcasts; and
• Netflix SD/HD streaming and Amazon Unbox SD/HD PPV

TiVo recently announced plans to support On Demand with cable providers that use VOD systems from SeaChange. This capability is coming to the TivoHD later this year, although no further details are available, beyond what is mentioned in the press release. Comcast uses SeaChange to deliver its On Demand in most, but not all markets. Comcast has not said whether it will support this upcoming functionality on TiVo in markets that use VOD systems from SeaChange.

If you would like to learn more about the TiVo, or are a new TiVo owner, see the AVS TivoHD FAQ.

Moxi
The Moxi DVR includes a 500GB drive (75 HD hours); it also supports external drives up to 2TB. It costs $799 from Amazon.com, but that price includes a lifetime subscription for guide data and updates, so there are no future fees.

Video Demos of Moxi: Demo for Engadget | CrunchGear

Moxi advantages compared to the TivoHD:

•16:9 HD menus with crisper, sharper, text and graphics
•Picture window on every menu screen that shows the current liveTV channel and/or current recording.
•1.5 hour HD buffer per tuner (compared to 30min HD buffer per tuner on TiVo)
•Can record three cable channels at the same time (two digital, one analog) when the free WinTV-HVR-1950 USB tuner is connected.
•Clear QAM channel mapping through a web interface to fully support HD locals on cable -- with program information-- without the need for a CableCard.
•DLNA 1.0 client support allows access to music, photos, and videos on computers, network attached storage, mobile phones, and other devices without proprietary software.
•Conflict management allows you to choose which of the two conflicting programs you would like to skip. You aren't limited to skipping the lower priority program.
•No advertising whatsoever in the UI.
•Storage expansion works with any external eSATA drive up to 2.0TB, not just the My DVR Expander (500GB, 1TB).
•External drives can be added and removed at will to archive recordings; recordings are not split across internal and external drives, so recordings are not lost when a drive is removed.
•Adjustable duration on skip button (30 seconds, 3 minutes, etc).
•Ability to display a small guide at bottom of the screen.
•On-screen widgets for weather, sports scores, stock quotes, etc, updated in real time.
•Online scheduling with real time conflict resolution and the ability to edit/delete recordings online
•Includes backlit remote (included with 1TB TivoHD XL, but a $50 option on the standard TivoHD)

Moxi disadvantages compared to the TivoHD:

•$799 @ Amazon.com with lifetime service and 500GB drive; there is no option to purchase for less with monthly or yearly fees
•No ATSC (OTA) support; the Moxi is cable only.
•No built-in support for analog channels; customers must request a free USB device to add a single analog tuner to the box.
•Cannot download or transfer recordings to a computer; cannot view DVR recordings on a computer.
•No support for multi-room viewing (Moxi plans to add this feature later this year).
•No wishlists or comparable functionality (can't record based on search).
•No overlap protection, so 1-2 minute program overlaps cause conflicts that can result in missed recordings.
•Does not keep a record of recorded programs to prevent re-recording the same programs after they are deleted from the DVR.
•No display of recorded history or missed programs due to conflicts; if a program is not recorded due to a conflict, there is no record of that on the Moxi.
•Lacks "traditional" grid-based program guide and shows less program information on screen than TiVo.
•No manual recording screen. You can only create recordings from the program guide or by selecting a search result.
•When you stop or finish a recording, the Moxi always displays a liveTV window, even when that is a recording-in-progress (such as a sporting event); there is no way to exit a recording without seeing the liveTV window.
•No option to use a phone line for guide downloads; a network connection is required, using a direct run of ethernet cable, a wireless bridge, a powerline adapter, or a MoCA adapter.
•No support for Netflix's HD; only supports Netflix SD, and only does so when a Windows PC is on and running the PlayOn software.
•No support for Amazon Unbox's HDTV VOD service with series and movies downloads in 1080p24 with DD5.1 ($4.99 per HD movie, $2.99 per HD episode).
•Auto-correction on FF / REW not as accurate as TiVo (subjective)
•Interface not as intuitive (subjective)

If you would like to learn more about the Moxi, see the Moxi web site.

Moxi and TiVo have different design philosophies. Moxi provides more features and options for liveTV viewing and display, whereas TiVo provides more features and options for recording. If you watch 60% liveTV and 40% recorded, you'll probably be happier with Moxi; if you watch 20% liveTV and 80% recorded, then you'll probably be happier with TiVo.

Tru2way devices require and use the same CableCards as the TivoHD and Moxi, but they also incorporate a bidirectional hardware receiver and a Java virtual machine. Tru2way devices download and run a Java version of the cable company's STB/DVR software. This allows the cable company to provide their own interface, guide, and VOD on customer-owned hardware. In 2010, users should be able to purchase tru2way DVRs for under $400 with much greater capacity and support for external storage.

The obvious disadvantage of true2way is that functionality is limited to whatever Comcast offers in your particular market. With true2way DVRs, Comcast retains exclusive control over what options you have for the software and interface. If the Comcast STB/DVR software is chock full of advertisements, or it limits how you can skip commercials, then that is what you get on the tru2way box. At this time, it is unknown whether customers will be able to eliminate their DVR service fees with the purchase of a tru2way box. Tru2way equipment still needs Comcast software to function, and there is nothing that says that software must be completely free.

A hearty thanks to KenAF and miscDude for their contributions to this FAQ entry.

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by sansri88
last modified: 2009-05-18 21:19:54

• What is QAM
• What is a DTA? What channels can I get with a DTA
• How does Comcast's Video Distribution Network Work?
• What are the national 3:1 HD muxes from Comcast?

(back)QAM stands for Quadrature amplitude modulation. It's a modulation scheme that transmits data by changing the amplitude of two carrier waves. The two carrier waves are out of phase with each other by 90 degrees. Digital Cable uses QAM to transmit the majority of their signals. Two major QAM schemes are 64QAM and 256QAM. 64QAM contains data throughput around 28 mbps, where 256QAM has data throughput of 38.8 mbps.

If your TV has a QAM tuner, it has the ability to read this signal and display it. The cable company can encrypt the digital video carried in a QAM signal and this is commonly referred to as Encrypted QAM. To receive Encrypted QAM, you would require a cable card or an official Comcast digital receiver. A QAM tuner on a TV or DVD recorder does not 'map' the channels to the same location on the Comcast channel lineup card. A QAM tuner will display unencrypted channels on their physical location in relation to the frequency they are carried on.

Some area's are able to pass PSIP data along with local broadcasts. PSIP data is embedded in the digital information that tells your TV what channel number to display. For example, Channel 3 in HD may embed 3.1 in it's video stream. Your TV would be able to tune this by typing in 3-1. Each Comcast area is different, and some may not pass PSIP, so look for HD locals on odd numbers, such as 113.1, etc..

It's also recommend to force your TV or DVD recorder to rescan the QAM channel lineup from time to time. Additional channels may show up unencrypted or may of changed frequencies. Comcast does not guarantee channel availability through a free QAM tuner.

If your looking for a QAM channel lineup, there is no official one from Comcast. You could try the SiliconDust HD-Home Run page. Enter your zip code at this following website:
»www.silicondust.com/hdhomerun/channels

Then choose your Comcast service from the pick list menu.

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by cypherstream edited by sortofageek
last modified: 2011-01-26 14:57:52

(back)DTA stands for Digital Transport Adapter. It's a very cheap and basic cable box that allows you to watch, with digital quality picture and sound, in Comcast words, all Limited Basic and Expanded Service channels, as well as "certain" Digital Starter channels. In other words, a DTA is a unencrypted QAM receiver for an analog TV. Comcast can remotely program the DTA with the correct channel lineup up until Expanded Basic. (Usually the first 99 channels). Consult your local Comcast center for an applicable channel lineup card for details.

Currently Comcast is offering in many markets the first 2 DTAs for free and it's charging 1.99(plus taxes and fees) per DTA after the first 2 ones. You should keep in mind that usually Comcast doesn't charge anything for the first digital box if you subscribe to a Digital Starter and above package.

The main reason Comcast is offering the DTAs is to allow Comcast to push as many analog channels to digital as possible, freeing up bandwidth for faster Internet speeds, more HD channels, etc.

Special credit to SND2005 for taking pictures of the DTA and allowing us to post them in the FAQ.

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by Travelfan1 edited by cypherstream
last modified: 2009-05-22 15:21:07

(back)The Master Headend or does their bit in aggregating and sending the video signals in MPEG format across the CRAN network. From the cran it goes to the various local headends via Multicast UDP through routers. Finally the local hub picks up the signal and converts it to RF to shoot out over the network. There is also a VOD server farm, which could reside in it's own building or in a regional headend depending on the local archetecture either built by Comcast, or inherited from acquisitions. VOD has been known to spread apart to other larger headends in the region for redundancy. There are various hubs spread out along the plant house the OOB communications equiptment and the VOD (and potentially SDV) edge qams.

There are digital controllers that address all of the set top boxes in the area's. For Scientific Atlanta sites there's a *NIX based server called the DNCS, while Motorola sites there is a server called the DAC. While DNCS's and DAC's pretty much do the exact same job, the way they do it on a SA plant vs Motorola plant are ENTIRELY different. Motorola tends to break things out a bit more with NC1500's, RPD's, etc.....While SA tends to centralize things a bit more within it's DNCS/Appserv setup.

Definitions:
Headend - The control center of a cable-television system, where incoming signals are amplified, converted, processed, and combined into a common cable for transmission to subscribers.
CRAN - Comcast's Reginal Area Network
Multicast - network technology for the delivery of information to a group of destinations simultaneously using the most efficient strategy to deliver the messages over each link of the network only once, creating copies only when the links to the multiple destinations split.
UDP - A communications protocol that is mostly used to send streamed material over a Network
VOD - Video On Demand
SDV - Switched Digital Video - A method of broadcasting only channels that are currently tuned, rather than every channel offered at once.
DNCS -Digital Network Control System
DAC - Digital Addressable Controller
SA - Scientific Atlanta (now owned by Cisco).
NC1500 - Motorola device that links application servers and set-tops using Internet Protocol (IP) to deliver data packets through the out-of-band data channel.
RPD - Motorola's Return Path Demodulator for interpreting commands from the Motorola Cable Box back to the Cable Headend.
OOB - Out of Band communication. Method used to program cable boxes remotely, while allowing their tuners to be on any channel.

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by cypherstream
last modified: 2009-05-22 15:51:09

(back)Although this list is not complete, here are the majority of the Muxes from Comcast Media Center. They are available on the CRAN network, and some of them are available via Satellite. For an explanation of CRAN and what it means for you, please see this entry courtesy of our friends in Comcast HSI: »Comcast High Speed Internet FAQ »What is CRAN?

A 3:1 HD mux means 3 HD channels in 1 38.8mbps QAM. Instead of dedicating 19.4mbps for one HD channel, it is varied depending on the channels on each QAM. As of late Comcast has modified their "muxes" in order to improve picture quality; they place 2 1080i channels and 1 720p channel together.

Mux 1 Starz East, HGTV, A&E
Mux 2 Food, SciFi, UniversalHD
Mux 3 Discovery, USA, NatGeo
Mux 4 HDTheater , Animal Planet, History
Mux 5 HBO East, Max East, TLC
Mux 7 AMC, Golf, CNN
Mux 8 Disney, ABC Family, Science
Mux 9 FX, Speed, Fox News
Mux 11 IFC HD, WE HD, Fuse HD
Mux 12 Encore HD, Fox Bsiness, Hallmark Movie Channel
Mux 14 Bravo, CNBC, QVC
Mux 15 MGM HD, ESPNews, Toon Disney
Mux 16 Lifetime Movies, Biography, Planet Green
Mux 17 E!, Travel, Cartoon
Mux 18 Starz Edge, Starz K&F, Starz Comedy
Mux 19 Spike, Lifetime, Nickelodeon
Mux 20 G4, Style, TV One

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by cypherstream edited by sansri88
last modified: 2009-02-13 17:01:47