Cisco Headend Digital Broadband Delivery System User Guide

4002178 Rev C 

Channel Selection Options 

3-19 

System operators have identified a need for CableCARD™ hosts to tune different 

sources when a particular service is selected based on the capabilities of the host. 

Fully interactive set-tops with a CableCARD slot can operate as a two-way 

CableCARD host, while the majority of retail CableCARD hosts do not and are one-

way only.  For example, the vast majority of CableCARD host televisions sold at 

retail stores are one-way devices and cannot perform interactive services like VOD. 
A new feature in the Digital Network Control System (DNCS) allows you to specify 

two sources for a single Service Application Manager (SAM) service. This feature 

allows you to identify one source for two-way CableCARD hosts, as well as existing 

set-tops with embedded security, and another source for one-way CableCARD hosts. 
In addition to adding the ability to tune to a different source, a second capability has 

been provided. You can now hide services from a one-way CableCARD host. This 

additional capability allows you to offer selected services to only the existing 

embedded security set-top population as well as to the newer two-way CableCARD 

host devices. 
This section provides the procedure for specifying two sources for a single SAM 

service. This procedure is useful when provisioning one-way CableCARD host 

devices (for example, most retail televisions with CableCARD slots). A procedure for 

hiding services from one-way CableCARD hosts is also provided. This procedure 

does not affect services on two-way hosts such as newer CableCARD host-equipped 

set-tops 

The DNCS builds the channel map (that is passed from the CableCARD module to 

the CableCARD host) by looking for SAM services with a watchtv or music 

application URL. Typically, any service using one of these URLs will be put into the 

CableCARD channel map. The DNCS allows you to add an extension to the SAM 

services application URL in order to cause one of the following behaviors:  
• 

The CableCARD host will tune to an alternate source ID when the service is 

selected. 

• 

The DNCS will not include the service in the CableCARD channel maps when 

they are built. 

In addition, you can use this feature to prevent PPV and IPPV services from 

displaying as "black screen" services on one-way CableCARD hosts. This condition is 

prevented by modifying the URL for the event use service that is associated with the 

PPV/IPPV service. As indicated earlier, these modifications only impact the service 

information sent to one-way hosts.