Digital Transport Adapters (DTAs) are one-way devices that convert incoming digital signals into analog signals that can be viewed by older television sets. Most are simple "channel zappers" that do not support on-board electronic program guides nor can handle interactive applications such as video on demand (VoD). Their inherent one-way capabilities also prevent them from viewing channels delivered in a "switched" tier.
Some MSOs, most notably Comcast Corp., are using DTAs to fuel analog reclamation strategies. In the Comcast example, the MSO is migrating channels from its analog advanced basic tier to digital format. Once that occurs, analog TVs would then require a DTA (or a regular set-top box) to view those channels. (See Comcast's $1B Bandwidth Plan and Comcast Seeds Digital Shift With Free Boxes.)
Several vendors have developed DTAs for the U.S. cable market. Pace Micro Technology, Motorola Inc., Cisco Systems Inc., and Thomson are all already on board as DTA suppliers to Comcast. Evolution Broadband LLC, meanwhile, has developed a DTA (using the Digital Video Broadcast, or DVB, platform) it's targeting to small- and mid-sized MSOs as a component of a broader all-digital video platform. (See Evolution Thinks Small .)
The DTA market has not developed without controversy. A July 2007 Federal Communications Commission (FCC) mandate prevents MSOs from deploying set-tops with integrated security, forcing most MSOs to deploy set-tops with the removable CableCARD. DTAs, at $35 to $50 per unit, are said to cost hundreds of dollars less than an entry-level, CableCARD-based set-top. (See Countdown to 'Seven-Oh-Seven'.)
In June 2009, Evolution obtained a three-year waiver to couple its DTAs with an integrated conditional access system from Conax AS. Since then, several parties have urged the FCC to rescind it on the notion that the waiver will hinder CableCARD adoption and undermine the development of a retail market for TVs and set-tops based on the tru2way platform.
Cisco, Moto, Thomson, and Pace are also seeking similar waivers at the FCC for DTAs that can activate a "latent" content protection scheme via a firmware upgrade.
The current DTA crop can display standard-definition video, but Evolution is working on a model that can feed through and display high-definition programming.
For more on DTAs, please see: