In its effort to reclaim analog spectrum, Comcast Corp. (Nasdaq: CMCSA, CMCSK) has gotten down to its most basic video service tier.

It's possibly the last phase of Project Cavalry, where Comcast is distributing Digital Terminal Adapter (DTA) devices to shift channels to digital format, freeing up valuable analog capacity. The initial phase converted 35 to 40 channels, and now Comcast is working on the rest -- those in its most basic "B1" packages (an average of about 20 channels, depending on the system). (See Comcast's $1B Bandwidth Plan and Comcast Sends In the All-Digital 'Cavalry'.)

A Comcast spokeswoman estimates that this phase -- which is underway in Philadelphia, Indianapolis, Houston, Chicago, Boston and other markets -- is 22 percent complete. It started in March 2010 with Augusta, Ga., which coincidentally is the technical trial site for Xcalibur, a nimble video platform that will rely heavily on the cloud. (See Comcast to Swing Xcalibur Wide in 2012, Comcast Tests Broadband-Fed Xcalibur Service and Comcast Courts the Cloud.)

Customers with older analog TVs will be forced to use set-top boxes to get B1 channels. While some customers will certainly howl about that, Comcast is trying to appease them by offering three free DTAs. (Comcast offers two DTAs and one interactive, VoD-capable set-top for free to customers who subscribe to B2, the advanced basic tier). (See Comcast Seeds Digital Shift With Free Boxes.)

All this reclaimed spectrum is going toward more digital services. The MSO, for example, is increasing its HD lineup to about 120 channels from about 100 in B1 migration markets, while reserving capacity for other future services such as Xcalibur.

Comcast is migrating B1 to digital just as the U.S. cable industry is urging the Federal Communications Commission (FCC) to let MSOs encrypt their basic tier once they've gone all-digital. Cablevision Systems Corp. (NYSE: CVC) obtained a special waiver from the FCC about a year ago to do so, meaning that customers who use digital TVs with embedded QAM tuners to receive basic channels "in the clear" are now required to use set-tops or TVs that can support the CableCARD, or boxes that support the MSO's new downloadable security system. (See Cablevision Looks to Lock Up Basic Video Tier .)

DTAs don't use CableCARDs, but the models Comcast deploys are capable of activating a content protection scheme called "privacy mode." (See Comcast Lights Up DTA Encryption .)

— Jeff Baumgartner, Site Editor, Light Reading Cable