Switched Digital Video (SDV) allows cable operators to send certain channels to customer’s homes only when the channels are requested. This technology gives your cable provider the ability to more efficiently use the existing bandwidth to offer more channels.

NOTE: Switched Digital Video only affects HD TiVo DVRs, and is not related to the transition to digital antenna signals. If you have a Series2 DVR and want information about converter boxes, click here.

TiVo does not distribute Tuning Adapters – only your cable provider can do that – but with the most current software update, your HD TiVo DVR is fully compatible and ready to display SDV channels as soon as a Tuning Adapter is installed. 

The following sections give an overview of how SDV works. In addition, this article includes the following information:

Where to get a Tuning Adapter

Connecting a Tuning Adapter to your TiVo DVR

Does the DVR still need CableCARD(s)?

Programming and data flow

What if a cable is disconnected?

Requesting an SDV channel

How recordings work

When does a channel “switch away”?

Program guide data and your channel lists

TiVo upgrades and exchanges 

Cable without SDV

In this example, the cable provider is broadcasting every channel in the lineup at the same time, consuming all the bandwidth, even though the customers in the area are only tuning to a small subset of the channels.

Cable with SDV

In this example the cable company is sending only the channels the customers are currently tuning to. Notice that bandwidth is now available for additional channels.

Two-way communication is required

Before you can view or record a program on an SDV channel, your DVR must be able to send channel requests back to the cable headend. HD TiVo DVRs are one-way devices, so they cannot send the required channel requests.

Starting soon, cable providers who have deployed SDV technology in their headends will begin issuing Tuning Adapters to customers who have HD TiVo DVRs. A Tuning Adapter is a set top box that provides two-way capabilities, so your DVR can request SDV channels. (Series2 and Series2 DT DVRs are unaffected, because they can use a cable box to provide two-way communications.)

IMPORTANT: At present, cable providers are not planning to offer access to VOD (video on demand) programming through the Tuning Adapters.

There are two Tuning Adapter brands, Motorola and Cisco. Motorola CableCARDs work with Motorola Tuning Adapters. Scientific Atlanta and NDS CableCARD work with Cisco Tuning Adapters.

Where to get a Tuning Adapter 

Like your CableCARDs, the Tuning Adapter must be issued by your cable provider. The Tuning Adapter will not have to be customized for the DVR, however; like a cable box, the installer can simply connect the Tuning Adapter and it is ready to go.

Tuning Adapters are in the process of being field tested by major cable providers, and this testing must be completed before these devices are rolled out to the general public. Some cable providers plan to send installers to connect the Tuning Adapters. Some will allow their customers to pick up the Tuning Adapters from a local office and install them themselves.

If switched digital video is already in your area, or is about to roll out to your area, you will receive a letter from your cable provider telling you what options are available.

Connecting a Tuning Adapter to your TiVo DVR 

You can connect the Tuning Adapter to your TiVo DVR during Guided Setup or at any time after the DVR completes Guided Setup.

The following illustration shows the cabling between an HD TiVo DVR and a Tuning Adapter. (Not shown: power cords plugged in to outlets.)

1. Attach the cable from the wall into the RF In connector on the Tuning Adapter. 
2. Connect one end of a coax cable from the RF Out connector on the Tuning Adapter. Connect the other end to the RF In connector on the DVR. 
3. Connect the Tuning Adapter’s USB cable to the USB port on the Tuning Adapter. Connect the other end to one of the USB ports on the TiVo DVR. 
4. Attach the power cord between the Tuning Adapter and an electrical outlet.

The first time you connect the Tuning Adapter, you will see “Please wait…Acquiring channel information.” for a few minutes while the Tuning Adapter channel list is downloaded.

When the download is complete, the Tuning Adapter is ready to operate.

Does the DVR still need CableCARD(s)? 

Yes. CableCARDs are still required to decrypt encrypted programming and to decode copy-protected channels.

Your CableCARD(s) will need to be authorized for the additional channels. Some cable providers will allow their customers to pick up a Tuning Adapter at a local office and will “hit” the CableCARDs remotely to authorize them to display all the channels in the SDV lineup. Some will send an installer to connect the Tuning Adapter and either swap out the CableCARD(s) or call in to get the existing ones re authorized. Still others may offer multiple installation options. Your cable provider will give you complete information when they roll out Tuning Adapters in your area.

If the Tuning Adapter is not operational because it is disconnected, powered off, in standby mode, or is getting a firmware update, the DVR uses the channel map on the CableCARD to tune to your channels. During these times, you will not be able to view or record programming on SDV channels.

Programming and data flow 

The RF cable from the wall to the Tuning Adapter to the DVR carries in-band programming (the shows you watch) and out-of-band communications, including channel maps for the Tuning Adapter and CableCARD(s). If the Tuning Adapter is disconnected, in standby mode, or powered off, the DVR still receives the RF signals. While the Tuning Adapter is powered on, it boosts the signal strength slightly, so that there is no drop in signal strength due to the Tuning Adapter’s operation.

Channel requests go from the DVR to the Tuning Adapter over the USB connection. The DVR can only detect the Tuning Adapter if the two are connected by a USB cable.

What if a cable is disconnected? 

If the RF cable between the Tuning Adapter and the DVR is unplugged (or the RF cable between the wall and the Tuning Adapter, for that matter), you see the message “Searching for Signal” because the DVR is missing its program stream.

If the USB cable is disconnected, you will see this message. When you press SELECT to continue, the DVR will begin to use the CableCARD channel map(s) for all new tuning operations. You will not be able to view SDV channels.

When you reconnect the Tuning Adapter, you will see the following message. Press SELECT to continue. You will now be able to access all your channels, including SDV channels.

Requesting an SDV channel 

You request an SDV channel in the same way you tune to a channel when no Tuning Adapter is attached: use the CHAN UP/DOWN button, select the channel from the Guide, or enter the number using the buttons on the remote. If the channel is not currently broadcasting to your neighborhood, an SDV server at the headend sets the channel up on one of the unused frequencies and sends the programming to you. The time to set up the channel and send the tuning information to the DVR is so short that you may not be able to tell the difference between this operation and a conventional channel tune.

Each time you tune to a channel, a timer on the SDV server resets for that channel. After a time period chosen by your cable provider elapses (usually a few hours), you will see the following message:

The SDV server uses this communication to determine if someone is actively watching the channel or if the TV was simply tuned to that channel when it was turned off. If you press SELECT, the timer for the channel resets.

If you do not press SELECT, the server may temporarily remove the channel to make room for another, requested channel. If this happens you will see the following message:

To get the channel back, simply tune to it. If bandwidth is available, the server will set the channel up again. If you still see this message, it means that there is no bandwidth available to send you the channel.

IMPORTANT: Cable providers are working very hard to “size” SDV areas so that all customers in each area receive the channels they request. SDV and Tuning Adapters are very new technologies that are being deployed rapidly, however. While it is possible for you to request a channel that the cable provider does not have the bandwidth to send, this should be very rare. If you have any concerns about SDV or Tuning Adapter operations, please contact your cable provider.

How recordings work 

When the DVR begins a recording, it sends a signal to the Tuning Adapter that includes a channel request and the information that it is recording. While the recording is in progress, the Tuning Adapter sends periodic signals to the headend to indicate that the channel is in use, so your recordings do not get cut off.

When does a channel “switch away”? 

A channel may switch away when a channel reaches its timeout and no one in the area confirms that they are still viewing the channel and no recordings are detected. Some SDV servers remove the channel immediately. If the DVR is tuned to this channel, you will see the message “This channel is temporarily unavailable.”

Some SDV servers keep broadcasting the current channel until the bandwidth is required to meet another channel request. In this case, the original request to press SELECT to stay on a channel has timed out, and the channel switches off without any additional warning.

Program guide data and your channel lists 

There is only one set of program guide data for each headend. Your cable provider can tell you which channels are available without a Tuning Adapter and which channels you receive with a Tuning Adapter.

If you live in an area that already has SDV, and you have not yet received a Tuning Adapter, you can go into your channel list and deselect the channels you do not yet receive. When you receive your Tuning Adapter, you can go back into the list and add the new channels. To display the channel list screen from TiVo Central select Messages & Settings > Settings > Channels > Channel List.

TiVo upgrades and exchanges 

If you upgrade your DVR to a newer HD model or if your HD TiVo DVR needs repair and you receive a replacement from an exchange, you can connect the Tuning Adapter to your new DVR and it will be operational immediately. All channels that are not copy protected, including SDV channels, will be visible.

You will still need to call your cable provider to get the CableCARD(s) paired to your new DVR before you can view copy-protected channels.