Broadcasters are prepared to announce later today that Washington D.C. will be the first U.S. city to receive free digital TV (DTV) transmissions for their mobile devices. Broadcasts using the mobile DTV technology are expected to be available at some point in July or August, and will be provided by local affiliates of CBS, NBC, PBS, FOX and Ion.

Initial broadcasts will be indistinguishable from those sent to television sets, meaning that current mobile phones, laptops and in-car entertainment systems won’t be able to take advantage of the service. While mobile phones are a leading candidate for adoption, most major carriers offer their own paid TV services and thus are hardly jumping in line to sign up for the free broadcasts.

Some of the more recognizable companies backing the new technology are Dell, Samsung, LG and Kenwood. Dell is expected to show a laptop prototype featuring a built-in mobile DTV receiver at the National Association of Broadcasters trade show in Las Vegas this week, and Kenwood is said to be developing car-based receivers.

The service is projected to make its way to a couple dozen other cities, including Atlanta, Boston, Chicago, New York, Philadelphia and San Francisco.